View Full Version : Marco's 'tube rolling' and valve power amp adventure
Vinyl Grinder
05-03-2008, 16:59
Moved from another thread:
I'm doing some 'tube rolling' with the Yaqin, and very interesting it is, too... :wow:
Marco.
You changed those ''Electron'' 'KT-88's yet ?
Andre,
Nope, mate - they're next on the list, to be replaced with cryo'd 'Winged C' Svetlana KT88s...
The Chinese 12AX7s have been replaced with Cryo'd 12AX7 Svets, and the Chinese 6N8Ps replaced with Cryo'd Svet 6SN7s - the difference is not subtle!!!
I'm also upgrading the valves in the Croft with NOS Mullard military spec ECC83 and brown base ECC35s.
Marco.
Vinyl Grinder
05-03-2008, 19:38
Andre,
Nope, mate - they're next on the list, to be replaced with cryo'd 'Winged C' Svetlana KT88s...
The Chinese 12AX7s have been replaced with Cryo'd 12AX7 Svets, and the Chinese 6N8Ps replaced with Cryo'd Svet 6SN7s - the difference is not subtle!!!
I'm also upgrading the valves in the Croft with NOS Mullard military spec ECC83 and brown base ECC35s.
Marco.
You of all people to fall for the cryo crap..Had that crap with the CD's few years back didn't we...Your not too concerned about what the high intensive heat does to the valve in the long run then?
Mmm... I don't know if the cryo thing is crap or not yet. I've still to evaluate that one properly.
One thing's for sure though Chinese valves are shit (in comparison to something more decent)!
NOS military spec is the way to go and my favourite tube so far is Mullard.
Marco.
Steve Toy
05-03-2008, 19:58
Cryogenics does not involve heat. It involves freezing to nearly absolute zero.
I don't think that's what Andre means, Steve.
Marco.
Vinyl Grinder
05-03-2008, 20:56
No Steve it's not what i mean.
Try the Electro Harmonix tubes Marco..
I've tried EH KT88's in my amp, good tubes. Svetlanas are better though, IMHO. I'm using re-issue Gold Lion cryo KT88's at the moment, but TBH I think I'll be going back to the Svet's. Outstanding valves!
I have a spare quad of Svetlana's if anyone wants to give them a try.
As for the Svet 12AX7's, forget it! The only ECC83/12AX7 I've tried that was worse was a Golden Dragon. There are MUCH better ECC83 type valves to be had.
Vinyl Grinder
06-03-2008, 00:23
I've tried EH KT88's in my amp, good tubes. Svetlanas are better though, IMHO. I'm using re-issue Gold Lion cryo KT88's at the moment, but TBH I think I'll be going back to the Svet's. Outstanding valves!
I have a spare quad of Svetlana's if anyone wants to give them a try.
You tried 6550 in it?
I've tried EH KT88's in my amp, good tubes. Svetlanas are better though, IMHO. I'm using re-issue Gold Lion cryo KT88's at the moment, but TBH I think I'll be going back to the Svet's. Outstanding valves!
That's interesting, Mike. The Golden Lions are supposedly much revered. However I suspect that the current re-issues are manufactured by a division of Sovtek and bare little resemblance to the original Genlex (or GE) design from the 1950s.
I have a spare quad of Svetlana's if anyone wants to give them a try.
If you don't mind, then yes definitely. It will allow me to hear the difference between those and the Electron KT88s in the Yaqin before shelling out on new set of cryo'd Svets.
I'll send you a PM :)
As for the Svet 12AX7's, forget it! The only ECC83/12AX7 I've tried that was worse was a Golden Dragon. There are MUCH better ECC83 type valves to be had.
Indeed. I prefer the Electro Harmonix 12AX7, but my favourite is the NOS Mullard ECC83 - yummy!
I even replaced the voltage regulator valve in the Croft (a NOS Amperex) for a NOS Mullard 85A2, which isn't really in the signal chain, and for some bizarre reason it made a difference... :scratch:
What are your favourite 6SN7/6SL7 or ECC35 types? I don't think there's anything to touch the NOS military spec ones, although they are pricey. My favourite so far are Mullard ECC35 brown base, and Tungsol. I also like the American NOS Philips ones currently for sale at Watford Valves for £16.
Marco.
I use NOS GEC KT88's in my valve amp, a work mate had a quad set of unused ones sat in his shed gathering dust! Also have a set of Svets
The OPTX's are important as the valves, I upgraded mine to a pair of custom wound from Sowter, they wasn't cheap but made quite an improvement over the standards
I use NOS GEC KT88's in my valve amp, a work mate had a quad set of unused ones sat in his shed gathering dust!
Nice find! How much did you offer him? ;)
Btw, any idea why my 'upgrading' the voltage regulator valve in my preamp would have made a difference (an improvement) to the sound? I'm a bit puzzled as to why this has happened as (as far as I'm aware) it's not in the audio signal chain. A brief idiot-proof explanation (if there is a technical one!) would be appreciated :)
Marco.
Vinyl Grinder
06-03-2008, 11:58
Nice find! How much did you offer him? ;)
Btw, any idea why my 'upgrading' the voltage regulator valve in my preamp would have made a difference (an improvement) to the sound? I'm a bit puzzled as to why this has happened as (as far as I'm aware) it's not in the audio signal chain. A brief idiot-proof explanation (if there is a technical one!) would be appreciated :)
Because the power supply in any amp is one of the most important sections, you can have the greatest designed amp in the world but if you aint got the juice department upto scratch, no use really.
Because the power supply in any amp is one of the most important sections, you can have the greatest designed amp in the world but if you aint got the juice department upto scratch, no use really.
I totally agree with that statement, as it has always been my experience, however I'm just a tad surprised at how much that particular component has impacted on the sound. Changing the Yugoslavian-derived Ei ECC83 above it for a NOS Mullard version was even more significant!
I will put a couple of them in the Yaqin to replace the new stock Electro Harmonix 12AX7s and report back in due course.
Marco.
You tried 6550 in it?
No - But it's on the 'to do' list! :)
That's interesting, Mike. The Golden Lions are supposedly much revered. However I suspect that the current re-issues are manufactured by a division of Sovtek and bare little resemblance to the original Genlex (or GE) design from the 1950s.
If you don't mind, then yes definitely. It will allow me to hear the difference between those and the Electron KT88s in the Yaquin before shelling out on new set of cryo'd Svets.
I'll send you a PM :)
Indeed. I prefer the Electro Harmonix 12AX7, but my favourite is the NOS Mullard ECC83 - yummy!
The current Gold Lions are "recreated down to the finest detail" (allegedly) by New Sensor Corp:
http://www.newsensor.com/ProductHighLight.aspx?ProId=1149
With regard to the Mullard ECC83 - I'm busy hoarding them :ner:
Try to get hold of a/some Mullard CV4004 types, they're based on the SQ version of the ECC83 - The M8137. The most yummy of all!
Brimar's are very very close too, as are smoothplate Telefunkens. If you're very lucky/flush you might find a Telefunken ECC803S - but don't hold you're breath!
Cheers,
Mike.
Nice find! How much did you offer him? ;)
Btw, any idea why my 'upgrading' the voltage regulator valve in my preamp would have made a difference (an improvement) to the sound? I'm a bit puzzled as to why this has happened as (as far as I'm aware) it's not in the audio signal chain. A brief idiot-proof explanation (if there is a technical one!) would be appreciated :)
Marco.
Actually it is Marco, at least as far as AC is concerned it can have a big effect on sound quality. It's more noticeable with SE amps than PP admittedly but even with PP amps it's still necessary to consider the PSU as part of the signal chain.
Hi Neal,
I agree, and it's definitely what I'm hearing. Last night at a friend's house we compared three different voltage regulator valves in a Croft preamp - all NOS, from Amperex, Mullard, and an unmarked military spec one, and they all sounded different.
However, where it's really at is the output valves. There are five inside the Croft, and NOS Mullard ECC35 brown base are, so far, much better than anything else I have heard.
Mike,
Try to get hold of a/some Mullard CV4004 types, they're based on the SQ version of the ECC83 - The M8137. The most yummy of all!
Brimar's are very very close too, as are smoothplate Telefunkens. If you're very lucky/flush you might find a Telefunken ECC803S - but don't hold you're breath!
Regarding the Mullard, that's very interesting. I will look into that. Now that I'm on a journey 'maxing-out' the Croft (and Yaqin), valve-wise, I know that I'll not be satisfied with anything but the best! :)
We tried a Brimar ECC83 last night and found it a bit warm sounding and 'polite' compared to the Mullard. What I've found with Mullards is that they just sound 'right', with no emphasis on any part of the frequency range - they have a lovely natural 'tone'. I've had no experience of Telefunken so far.
Marco.
Nice find! How much did you offer him? ;)
Btw, any idea why my 'upgrading' the voltage regulator valve in my preamp would have made a difference (an improvement) to the sound? I'm a bit puzzled as to why this has happened as (as far as I'm aware) it's not in the audio signal chain. A brief idiot-proof explanation (if there is a technical one!) would be appreciated :)
Marco.
He said I either take them or they are to be chucked in the bin, they was a spare set brought years ago for a big guitar amp which was long gone
As Neal mentioned the psu is part of the signal chain so the quality has an audible effect, upgrading the PSU's in almost all equipment influences the sound quality, some much more than others.
One of the reasons why a lot of solid state amplifiers,CDP's sound poor because of the cost cutting and poor implementation of the PSU, improve the PSRR and it usually improves the sound
He said I either take them or they are to be chucked in the bin...
Drats, what an inconvenience, eh?
I trust you replied along the lines of: "Oh ok, I suppose I can help out and take them off your hands..." :eek:
I totally agree about PSU quality being hugely important to performance - it's just that I didn't think changing a little voltage regulator valve would have such a profound effect on the sound.
I'm really enjoying this valve malarkey. This Yaqin Chinese amp is a phenomenal bargain. Frankly, its performance makes the price paid for it (£300 direct from China) a total joke. Even in its current state it's as good as any valve integrated or power amp I've heard up to £2K, and hooking it up to the Croft and using it as a pre/power combo takes it into a different league again.
Upgrading the relatively poor quality Chinese valves raises its game further and removes an annoying brashness in the midrange which opens up the sound quite dramatically, and by the time I've finished with it, having the unnecessary solid-state integrated circuitry removed and replaced with point-to-point hard wiring, a solid copper chassis designed to replace the current brass one, and the unit converted to 240V (without needing to use a step-down transformer) which I should be able to do for around £1500, I'm confident it will compete with some respected hi-end designs up to £5k.
Once this has been done I will write a full review for the benefit of anyone else considering going down this route. Make no mistake, this amplifier is a REAL giant-killer and is set no doubt to ruffle a few feathers in the UK valve scene!
Stay tuned, folks... :smoking:
Marco.
I've been trying to find info on this amp, is this the one you have
http://www.hi-end.on9mart.com/products/amplifiers/integ_amp/AI-YQ-100B/YQ-100B-01.jpg
http://www.hi-end.on9mart.com/products/amplifiers/integ_amp/AI-YQ-100B/YQ-100B-09.jpg
Yep, that's the fellow!
And as you can see from the second picture, there's a lot of circuit boards in there to rip out and replace with point-to-point wiring like there is in a proper all-valve design.
It sounds fantastic just now, used in conjunction with the Croft, particularly since upgrading the valves, but I think when the above mentioned modifications have been carried out it will sound truly amazing.
Do you think there would be any mileage in also upgrading the transformers, say with Sowters? They'll have to be changed anyway I would guess when the unit is altered to take 240V.
Marco.
Vinyl Grinder
09-03-2008, 13:25
Do you think there would be any mileage in also upgrading the transformers, say with Sowters? They'll have to be changed anyway I would guess when the unit is altered to take 240V.
http://www.hificollective.co.uk/transformer/custom_transformer.php
If your willing to spend on this thing I'd certainly upgrade the iron, especially the output transformers, although not cheap theres no way I'd go back to the supplied ones in my amp.
Of course its all down to the quality of the originals being used regarding performance boost.
Double C cores are reported to be the best but these can be mega expensive
You could always try some simple component changes on the pcb circuit to start with, most of those components look to be bog standard including what looks like polyester coupling caps, grid stopper resistors look like metal films and the electrolytics for the cathode bypasses look to be standard lytics, you could go nuts if you wanted:eyebrows:
Then theres the rectification which looks to be silicon based, could try some ultra fast diodes or the Cree high voltage schottkies before trying valve rectification
BTW I'd certainly play about with the existing PSU first before upgrading the PSU traffo, if you decide to go for valve rectification you'd probably need a different traffo anyway than whats used with solid state rectification
Theres a chance you may not like valve rectification in the amp;)
Interesting, Leo - particularly about the valve rectification. Does that have the tendency to make the sound 'softer'?
One of the things I like about the Yaqin is that it has the 'drive' and 'dynamic impact', for want of better expressions, of a solid-state amp, and yet also the subtleties and magical sounding midrange of valves. Maybe that's because there's a fair bit of solid-state in the Yaqin!
I can tell you though that simply upgrading the Chinese valves to Russian ones, from Electro Harmonix and Svetlana, significantly elevates its (already excellent) performance. As it is with the new valves it's easily as good as most £3k designs, which is remarkable when you consider that even with upgrading the valves I've spent no more than £500 including its original purchase value!
So ok, let's say you were modifying the Yaqin and had £1500 to upgrade it (which is the most I'd spend) which aspects of its design would you target first for modifying/upgrading?
I definitely want to do away with the internal circuit boards and fit point-to-point wiring, as I believe there is a 'signature' with printed circuit boards that you don't get with hard wiring, so apart from that, what else would you suggest doing? :)
Marco.
Vinyl Grinder
09-03-2008, 18:31
I definitely want to do away with the internal circuit boards and fit point-to-point wiring, as I believe that there is a 'signature' with printed circuit boards that you don't get with hard wiring
That's easier said than done, i hope you know what your doing, infact if your going to the trouble of that & replacing all the iron, why not just build another amp based on the circuit.
Yeah I know, you're right, but trust me I have enlisted the help of an expert, or at least I will be doing so in due course... There's no rush though at the moment as it sounds superb and I'm enjoying my music very much :)
Let's see what Leo has to say about things.
Marco.
Interesting, Leo - particularly about the valve rectification. Does that have the tendency to make the sound 'softer'?
One of the things I like about the Yaquin is that it has the 'drive' and 'dynamic impact', for want of better expressions, of a solid-state amp, and yet also the subtleties and magical sounding midrange of valves. Maybe that's because there's a fair bit of solid-state in the Yaquin!
I can tell you though that simply upgrading the Chinese valves to Russian ones, from Electro Harmonix and Svetlana, significantly elevates its (already excellent) performance. As it is with the new valves it's easily as good as most £3k designs, which is remarkable when you consider that even with upgrading the valves I've spent no more than £500 including its original purchase value!
So ok, let's say you were modifying the Yaquin and had £1500 to upgrade it (which is the most I'd spend) which aspects of its design would you target first for modifying/upgrading?
I definitely want to do away with the internal circuit boards and fit point-to-point wiring, as I believe there is a 'signature' with printed circuit boards that you don't get with hard wiring, so apart from that, what else would you suggest doing? :)
Marco.
So far and my honest opinion yes, I've always found valve rectification to sound softer in the bass than solid state rectification, pre-amps and lower current devices can be different but with a power amp I think valve rectification takes things too far , I've always found that deep and tight control of the speakers missing.
Others may disagree of course;-)
If I had 1500 to spend what would I upgrade, I can't comment on the output transformers as I don't know how good the standard ones are, if they was cheaply wound I'd certainly upgrade them, the improvement in sound I got with the Sowters in my system was not subtle, mainly noticed in the bass and dynamics, jmore effortless.
If the output transformers are already decent quality in the Yaquin then the benefits would be more subtle
Any valves that uses low voltage DC for the heaters is something worth looking at , ditching the standard rectifiers for high current schottkies is worthwhile doing, improve the decoupling as much as you can to lower noise, Guido Tent is supposed to sell some nice heater supplies if you don't fancy building something from scratch
Do the same with the HT supplies but obviously you need rectification and smoothing thats suitable for high voltage, lots of choice from the ultra fast type diodes to high voltage scottkies from Cree
Cathode bypass caps, anode resistors, grid stopper resistors, coupling caps, if it uses feedback then the components there are all parts that effect performance, if any of the parts especially capacitors look to be cheapo branded I'd change them to better quality, not just to improve the sound but mainly the reliability too, nothing worse than having crappy capacitors that go leaky inside a warm valve amp, poor quality parts tend to deteriorate quicker and this can be heard in the sound after a while
I tend not to recommend particular brands of capacitors and resistors as there is so many options and most of the boutique types like Blackgates can add signature, I'll let others comment on those, some swear that blackgates sound fantastic as cathode bypass caps.
I personally try to stick with reliable longer life, higher temp industry grade types
You'll certainly be able to hard wire this beastie although it will take some work, a handful of tag boards, good quality wire in there should sort it, just plan and draw it all out first, hopefully you can get a schematic which is really needed before doing anything anyway tbh, could even try different input valves if you are going to hardwire it although if the existing valves sound ok I wouldn't bother
With your current budget you have a huge amount of options
Interesting stuff, Leo.
I had a feeling that valve rectification might soften the sound - that is definitely not what I want, so unless someone knowledgeable can give me a good reason to go down this route then that particular part of the amp will remain solid-state.
Regarding the output transformers, would they need to be changed if the unit was converted to 240V? If not, then I might leave them as they are.
So apart from that, I'll probably just go for internal hard-wiring and having certain key components upgraded, which I will take advice on.
If anyone else who's knowledgeable about electronics would like to comment, please feel free. All input is welcomed! :)
Marco.
Hi Marco
Funny things you're doing there! Mind you Mullard was the brandname for Philips products in the UK.
You're not using an ECC83 in the amplifying chain I hope? That one has far too big input capacitance and you'll have a roll off at higher frequencies. In the past it was only used at phono input (that's where a roll off is needed). Nowadays a 6N1P (at 3 mA) does a better job there.
Oh and I love the Svetlana 6550!
Have fun
John
Interesting stuff, Leo.
I had a feeling that valve rectification might soften the sound - that is definitely not what I want, so unless someone knowledgeable can give me a good reason to go down this route then that particular part of the amp will remain solid-state.
Regarding the output transformers, would they need to be changed if the unit was converted to 240V? If not, then I might leave them as they are.
So apart from that, I'll probably just go for internal hard-wiring and having certain key components upgraded, which I will take advice on.
If anyone else who's knowledgeable about electronics would like to comment, please feel free. All input is welcomed! :)
Marco.
No, the output transformers are fine, its the main PSU traffo that needs changing, its primary windings are wired for the mains AC input but the secondary voltages remain the same
Vinyl Grinder
10-03-2008, 21:07
Interesting stuff, Leo.
I had a feeling that valve rectification might soften the sound - that is definitely not what I want, so unless someone knowledgeable can give me a good reason to go down this route then that particular part of the amp will remain solid-state.
Regarding the output transformers, would they need to be changed if the unit was converted to 240V? If not, then I might leave them as they are.
So apart from that, I'll probably just go for internal hard-wiring and having certain key components upgraded, which I will take advice on.
If anyone else who's knowledgeable about electronics would like to comment, please feel free. All input is welcomed! :)
Marco.
Your best taking the transformer in sowther for them to replicate you one to suite our voltage, they can make one to match the size of the original.. or who ever. you have a lot of things to take into account,you need your H.T voltages & other secondaries ie:heaters, you need to know what currents you require..is the amp useing input filter choke of capacitor etc..you got centre tapping percentages to consider...
Hi John,
Hi Marco
Funny things you're doing there!
Really - such as? :)
You're not using an ECC83 in the amplifying chain I hope?
Well yes, but only in my preamp (where there was already one fitted by the manufacturer). It was an Ei-branded Yugoslavian ECC83, which I replaced with a NOS Mullard ECC83, and the difference was very noticeable, i.e. much better!
That one has far too big input capacitance and you'll have a roll off at higher frequencies.
I can't say I've noticed that - in fact quite the opposite, the sound is much more open and detailed. However perhaps the effect you're referring to is relevant in another application?
Nowadays a 6N1P (at 3 mA) does a better job there.
When you say "there", John, where exactly do you mean - in the preamp or the power amp? In the Yaqin valve power amp it uses two 12AX7 valves at the front, four 6SN7s in the middle, and four KT88s at the back.
In the Croft preamp there are five ECC35 type (or 6SL7) and the single ECC83 above the rectifier valve.
Where would the 6N1P you're referring to go?
Oh and I love the Svetlana 6550!
What is the difference in sound between the 6550 and KT88? I have only heard KT88s.
Thanks for your help! :)
Marco.
Vinyl Grinder
10-03-2008, 21:54
Marco '6550' is a cleaner sound than 'KT88'
No, the output transformers are fine, its the main PSU traffo that needs changing, its primary windings are wired for the mains AC input but the secondary voltages remain the same
If the transformers are fine I'll probably leave them as they are. The thing is, the amp sounds great as it is, especially since I changed the Chinese valves, so I don't want to muck things up. You know what it's like when you've got a sound that you really enjoy - piss around too much and you can lose it!
My thinking at the moment is to go for the point-to-point wiring and probably upgrade the capacitors, and then leave well alone and enjoy the music, safe in the knowledge that I've got an absolute bargain :)
Marco.
Marco '6550' is a cleaner sound than 'KT88'
That's interesting, Andre. I'll look into that one, as I haven't finalised which main valves I'm using yet. It's between 'Winged C' Svet KT88s, Golden Lion KT88s, Tesla KT88s, or 6550s (which make is best I don't yet know) :)
Marco.
Leo's given you some good advise Marco but I can't help thinking the best way of spending 1500 quid in a diy manner would be to go out and buy a WD88V !
Point to point wiring ain't necessarily better in fact it can cause more issues especially if you are very neat and tidy with it. If you're still tempted to go-ahead and try some stuff then I would follow Leo's advise and start at the psu.
Not all valve rectifiers sound soft it does depend on implementation and amp topology, IE SE amps I think sound better for them than SS and the WAD 300B I have uses one as a soft start rectifier and it has plenty of speed and punch.
Vinyl Grinder
10-03-2008, 22:45
Personally i think i'd blow my cutter on the chrome chassis version of this.
http://www.audionotekits.com/kit1s.html
i think you can get a constructed one.
Leo's given you some good advise Marco but I can't help thinking the best way of spending 1500 quid in a diy manner would be to go out and buy a WD88V !
Point to point wiring ain't necessarily better in fact it can cause more issues especially if you are very neat and tidy with it. If you're still tempted to go-ahead and try some stuff then I would follow Leo's advise and start at the psu.
Not all valve rectifiers sound soft it does depend on implementation and amp topology, IE SE amps I think sound better for them than SS and the WAD 300B I have uses one as a soft start rectifier and it has plenty of speed and punch.
Is this Neal;) how doing matey
Got to admit I was impressed with the WD88V, very nice bit of kit that for the price!
That's interesting, Andre. I'll look into that one, as I haven't finalised which main valves I'm using yet. It's between 'Winged C' Svet KT88s, Golden Lion KT88s, Tesla KT88s, or 6550s (which make is best I don't yet know) :)
Marco.
I have a quad set of Svet 6550C's, bit lighter in the bass than the KT88's IMO but are nice valves, cheaper too!
You know I'm posting on here and my valve amp doesn't get much use anymore:o
Leo's given you some good advise Marco but I can't help thinking the best way of spending 1500 quid in a diy manner would be to go out and buy a WD88V !
Hi Neal,
Leo's advice has been great, as always. You're absolutely right of course about the WD88V, in fact I had considered this before buying the Yaqin. Thing is now I'm on a bit of a 'journey' with the Yaqin, and since I've been blown away by how it sounds with the Croft I'm keen to find out just how good it can get! :)
Point to point wiring ain't necessarily better in fact it can cause more issues especially if you are very neat and tidy with it.
I don't really understand. Can you explain?
If you're still tempted to go-ahead and try some stuff then I would follow Leo's advise and start at the psu.
I totally agree, and that's exactly what I'll be doing.
Not all valve rectifiers sound soft it does depend on implementation and amp topology, IE SE amps I think sound better for them than SS and the WAD 300B I have uses one as a soft start rectifier and it has plenty of speed and punch.
Interesting - it looks like I may have to do some more research in this area.
Marco.
Its a shame theres no easy way you could try a valve rectifier in the existing amp just to give an idea what effect it has on the sound
Hi Leo,
Fortunately there is :)
I know a chap who runs a business specialising in building valve amplifiers, and who has ordered a Yaqin with the specific intention of modifying it. I'll be in contact with him when he's doing the modifications and will ask him to let me hear the amp with and without a valve rectifier, and then decide myself which I prefer.
He's the one who'll be doing the point-to-point wiring and the rest of the modifications to my own Yaqin. Basically, when he's finished modifying his own one I'll have a listen and compare it to mine, find exactly what modifications he's carried out, and then if it's significantly better than mine I'll have mine done the same way.
I may also tailor the modifications to my own specifications if I consider some of what he has done is not to my taste; either way I'll be listening and judging things as the modifications progress. It should be very interesting. I will of course report my findings here in due course.
Marco.
Good idea MArco. It still won't beat a WD88VA though! :ner:
Who knows, mate. We could always do an A/B comparison when the Yaqin is fully tweaked.
Are you a betting man? ;)
Marco.
That confident, eh? :lol:
Marco.
Hi Leo,
Fortunately there is :)
I know a chap who runs a business specialising in building valve amplifiers, and who has ordered a Yaqin with the specific intention of modifying it. I'll be in contact with him when he's doing the modifications and will ask him to let me hear the amp with and without a valve rectifier, and then decide myself which I prefer.
He's the one who'll be doing the point-to-point wiring and the rest of the modifications to my own Yaqin. Basically, when he's finished modifying his own one I'll have a listen and compare it to mine, find exactly what modifications he's carried out, and then if it's significantly better than mine I'll have mine done the same way.
I may also tailor the modifications to my own specifications if I consider some of what he has done is not to my taste; either way I'll be listening and judging things as the modifications progress. It should be very interesting. I will of course report my findings here in due course.
Marco.
That will be ideal for you then, if he's a valve building specialist I'd imagine he'll have a few transformers stashed away including ones thats centre tapped secondaries etc suitable for valve rectifiers
Let us know how you get on
anthonyTD
12-03-2008, 14:54
An audio amplifier as a whole can be described in its simplest form as a voltage modulator, and that’s where the problems start, because what you really want it to do in a perfect world is to only modulate forward of the power supply, for this to happen the power supply would have to have an ultra low impedance at all audio frequencies,[brick wall] in the real world this is far from the case in both valve/tube and solid state. This is mainly due to the way the power supply is designed, ie,using capacitor/resistor networks which not only have to supply the correct current/voltage needed for the complex audio modulations, but also it has to cope with the ripple current rejection needed for a smooth power transfer at all amplitudes of signal… Any Capacitor resistor network will only have a relatively low impedances at certain frequencies; this is the main reason why all amplifiers have a particular sonic character, because to put it simple, they all have different impedance power supply characteristics. The reason you need ultra low impedance is to make sure that the analogue signal you are trying to reproduce cannot modulate the power supply, i.e., the lower you make the power supply impedance the less chance the signal has of modulating it!!! But this has to be a linear process, the power supply must have a low impedance at all possible audio frequencies!!! Capacitor resistor networks alone cannot possibly achieve this…
What happens when a power supply is able to modulate at certain analogue signals??? Simple, instead of the entire analogue signal being reproduced forward of the power supply, some of it will be lost through the power supply, and therefore won’t get any further down the chain. So, depending on where in the audio frequency range this critical low impedance acures in the power supply of any amplifier, valve, or solid state, this will play a big part in the characteristics of the sound you get…
So, an ultra low impedance power supply at all audio frequencies is a must for a perfect transfer “forward” of all audio frequencies
If you understand how impedance dominates power supply operation, then imagine how impedance affects the operation of all the different devices we use to reproduce the analogue signal, i.e., valves, mosfets, transistors!!!
Filterlab
12-03-2008, 14:55
Password worked then mate. :) You can change it to whatever you want now.
anthonyTD
12-03-2008, 15:38
Thanks rob...
Hi Anthony,
Great to see you here!
Interesting post - I'll comment later when I get a chance. Your experience and expertise will be invaluable to the discussion. In the meantime I'm sure Leo, you and Richard will have much in common :)
Marco.
An audio amplifier as a whole can be described in its simplest form as a voltage modulator, and that’s where the problems start, because what you really want it to do in a perfect world is to only modulate forward of the power supply, for this to happen the power supply would have to have an ultra low impedance at all audio frequencies,[brick wall] in the real world this is far from the case in both valve/tube and solid state. This is mainly due to the way the power supply is designed, ie,using capacitor/resistor networks which not only have to supply the correct current/voltage needed for the complex audio modulations, but also it has to cope with the ripple current rejection needed for a smooth power transfer at all amplitudes of signal… Any Capacitor resistor network will only have a relatively low impedances at certain frequencies; this is the main reason why all amplifiers have a particular sonic character, because to put it simple, they all have different impedance power supply characteristics. The reason you need ultra low impedance is to make sure that the analogue signal you are trying to reproduce cannot modulate the power supply, i.e., the lower you make the power supply impedance the less chance the signal has of modulating it!!! But this has to be a linear process, the power supply must have a low impedance at all possible audio frequencies!!! Capacitor resistor networks alone cannot possibly achieve this…
What happens when a power supply is able to modulate at certain analogue signals??? Simple, instead of the entire analogue signal being reproduced forward of the power supply, some of it will be lost through the power supply, and therefore won’t get any further down the chain. So, depending on where in the audio frequency range this critical low impedance acures in the power supply of any amplifier, valve, or solid state, this will play a big part in the characteristics of the sound you get…
So, an ultra low impedance power supply at all audio frequencies is a must for a perfect transfer “forward” of all audio frequencies
If you understand how impedance dominates power supply operation, then imagine how impedance affects the operation of all the different devices we use to reproduce the analogue signal, i.e., valves, mosfets, transistors!!!
Hallelujah! Praise Allah! Hail Thor! etc - The force is strong with this one Obi-Wan! A real tech-ie instead of a psuedo one.
Marco '6550' is a cleaner sound than 'KT88'
http://kiw.imgag.com/imgag/product/thumbs/3131452a.gif
Hallelujah! Praise Allah! Hail Thor! etc - The force is strong with this one Obi-Wan! A real tech-ie instead of a psuedo one.
Yes, Richard, I think you'll find that Anthony is 'top-notch' ;)
He's now my valve amp guru! :respect:
Marco.
P.S I wonder what he thinks of transformers vs. active MC stages, with regard to phono stages? :eyebrows:
P.S I wonder what he thinks of transformers vs. active MC stages, with regard to phono stages? :eyebrows:
He doesn't have to agree with me about everything to know what he talks about, as long as he speaks the language not just psuedo marketing speak. :flasher:
anthonyTD
12-03-2008, 19:38
P.S I wonder what he thinks of transformers vs. active MC stages, with regard to phono stages? :eyebrows:
The main problem when amplifying minute voltages ie, from low output moving coil cartridges is the noise factor, ie,the more you amplify a voltage signal the higher the noise floor becomes, so when your dealing with voltages in the miro-volt domain as with some of the best moving coil cartridges, you need to amplify the signal by a factor of a couple of hundred at least to be able to drive most modern pre-amplifiers, to do this you have to add more devices to the signal path, more devices more gain = more noise potential. when the noise floor goes up subtle detail is lost! step up transformers are in some cases a much better compromise than a badly designed high-gain active phono-stage..
All hail the Transformer! :youtheman:
:)
anthonyTD
12-03-2008, 20:05
Marco '6550' is a cleaner sound than 'KT88
Both valves 6550/KT88 are tetrodes, in some cases a 6550 can be described as having a bit more of an edge top end wise than a KT88 but this could be down to the fact that a 6550 has a slightly higher distortion factor than a KT88, the KT stands for "kinkless tetrode. however the sonic diffrences in most circuits are negligable, so much so that it has been known for some current manufactured 6550's to be re-branded as KT88's and vice versa, needless to say, both valves are exceptionaly good at what they do...
Both valves 6550/KT88 are tetrodes, in some cases a 6550 can be described as having a bit more of an edge top end wise than a KT88 but this could be down to the fact that a 6550 has a slightly higher distortion factor than a KT88
Some say (ooh!...enter 'The Stig'!) that as a result the 6550 can sound 'harsh' as a result!
All hail the mighty 'KT88'... King of tetrodes!
;)
I've read this thread througout and there are some things to be reconsidered (IMHO).
An amp and its behaviour should NOT rely on the power supply as such. On the contrary we don't want any influence from the power supply, be it impedance or mains noise or bad mains cables or rectifier noise. So best thing to do is to isolate the amplifier from the power supply. What's left then is the power capacitor. This component should offer a low impedance over the entire audio spectrum up to 100 - 200 kHz.
And Marco, if you're interested, you might review a new MC pre-amp of ours.
John
The main problem when amplifying minute voltages ie, from low output moving coil cartridges is the noise factor, ie,the more you amplify a voltage signal the higher the noise floor becomes, so when your dealing with voltages in the miro-volt domain as with some of the best moving coil cartridges, you need to amplify the signal by a factor of a couple of hundred at least to be able to drive most modern pre-amplifiers, to do this you have to add more devices to the signal path, more devices more gain = more noise potential. when the noise floor goes up subtle detail is lost! Step up transformers are in some cases a much better compromise than a badly designed high-gain active phono-stage..
That's what I've found, too, Anthony. What about a well-designed high-gain active phono stage vs. an MC step-up transformer? ;)
I still contend that if a step-up transformer and cartridge have been designed together from the ground up by the same manufacturer, as a pairing rather than as single entities, where the electrical characteristics of the cartridge (loading, impedance, gain, etc) have been taken into consideration at the design stage, and optimised, then this approach is likely to give better results than an (albeit good) active MC stage designed with no particular cartridge in mind.
Certainly this is what my experience (and ears) has told me. You can't design a 'one size fits all' phono stage because no two cartridge's sonic and electrical characteristics are the same.
Marco.
And Marco, if you're interested, you might review a new MC pre-amp of ours.
Hi John,
Yes I'm sure that would be interesting. PM me some details and we'll discuss it.
Marco.
I've read this thread througout and there are some things to be reconsidered (IMHO).
An amp and its behaviour should NOT rely on the power supply as such. On the contrary we don't want any influence from the power supply, be it impedance or mains noise or bad mains cables or rectifier noise. So best thing to do is to isolate the amplifier from the power supply. What's left then is the power capacitor. This component should offer a low impedance over the entire audio spectrum up to 100 - 200 kHz.
And Marco, if you're interested, you might review a new MC pre-amp of ours.
John
Sorry this is gobble-de-gook, are you tech-ie or marketing?
A power amplifier circuit is a power supply regulator, nothing more. BUT instead of regulating DC (the power supply rail(s)) it regulates the AC. A power amplifier IS a power supply. And what is a regulator, well if it were plumbing it would be the tap. It regulates flow, in this case electrons not water.
You cannot divorce an amplifier circuit from it power supply, the two are inherently indistinguishable if you are an electron. Even with class D the interdependence is crucial.
The main problem when amplifying minute voltages ie, from low output moving coil cartridges is the noise factor, ie,the more you amplify a voltage signal the higher the noise floor becomes, so when your dealing with voltages in the miro-volt domain as with some of the best moving coil cartridges, you need to amplify the signal by a factor of a couple of hundred at least to be able to drive most modern pre-amplifiers, to do this you have to add more devices to the signal path, more devices more gain = more noise potential. when the noise floor goes up subtle detail is lost! step up transformers are in some cases a much better compromise than a badly designed high-gain active phono-stage..
A bit too simplisitic, good as far as it goes, BUT the only gain function of a transformer is to exchange available current for voltage. How much current potential has a moving coil cartridge generated wiggling around on a piece of plastic, well not very much. So that derived voltage gain from the transformer is so weak it makes it over subject to loads of other viariables such as loading and hum characteristics and how it is used and connected. In reality a bag of nails. Now you can get it almost right but the overkill properties of the transformer involved make it enormously expensive, especially as you have to make the transformer as low loss as possible with exotic material winding / wiring and connection and masses of plate to keep up field strength.
Now thermal noise from active circuits is now capable of being taken incredibly low with modern op-amp technology and signal and noise floor relationships are still more to do with power supply and DC regulation than the gain characteristics of the circuit. As I have said before with valves active is no go so transformer is the *only* sensible option. With discrete or encapsulated modern op-amp circuits - no problem.
That's what I've found, too, Anthony. What about a well-designed high-gain active phono stage vs. an MC step-up transformer? ;)
I still contend that if a step-up transformer and cartridge have been designed together from the ground up by the same manufacturer, as a pairing rather than as single entities, where the electrical characteristics of the cartridge (loading, impedance, gain, etc) have been taken into consideration at the design stage, and optimised, then this approach is likely to give better results than an (albeit good) active MC stage designed with no particular cartridge in mind.
Certainly this is what my experience (and ears) has told me. You can't design a 'one size fits all' phono stage because no two cartridge's sonic and electrical characteristics are the same.
Marco.
A bit cart before horse, you are right but in a different way. With an MC and a tranny you have to get them to work as a synergy as you are working so close to what is possible. Solid state does not have this problem, you have so much headroom you can design for load rejection and make it almost a universal load.
Yes, but if you prefer the sound of valves to solid-state with vinyl (count me in!) and you've found a combination of MC cartridge and transformer that sounds better than any active MC stage you've heard then considerations such as those you've mentioned above are largely irrelevant :)
I totally agree with this statement, though:
With an MC and a tranny you have to get them to work as a synergy
And that's exactly what I get with my Denon DL-103 and Auditorium 23 step-up transformer.
Marco.
Yes, but if you prefer the sound of valves to solid-state with vinyl (count me in!) and you've found a combination of MC cartridge and transformer that sounds better than any active MC stage you've heard then considerations such as those you've mentioned above are largely irrelevant :)
I totally agree with this statement, though:
And that's exactly what I get with my Denon DL-103 and Auditorium 23 step-up transformer.
Marco.
But I can get the optimum out of any MC, I don't have to faff around with loading, humbucking or anything. It is not a valve v solid state argument. It is a tranformer v solid state argument, as valve doesn't sensibly even enter this contest. You could quite effectively use a solid state kick up to where the valves can take over. Yes I know it has been done before by Ortofon and others but that was years ago when plastic was in its prime, when the only low noise op-amp was TDA1034(philips) / NE5534(signetics) family devices . Now we are light years ahead of that in low noise and wide bandwidth technology.
With respect, Richard, none of that matters if the simple fact is you prefer the sound of valves to solid-state with vinyl. This is the crux of the matter as far as I'm concerned, and is why no matter how good or technically accomplished your active MC stage is I would be unlikely to buy it.
The best sound with vinyl I've ever had when using an MC cartridge without a shadow of a doubt has come from combining a well-designed quality all-valve MM phono stage (such as that in my Croft preamp) with an MC step-up transformer that's been designed to match and partner a particular cartridge, in my case the Denon DL-103 Pro and A23 step-up tranny.
The fact is no matter how good or how technically 'correct' your active MC stage is it won't give me the sonic presentation of my Croft MM valve phono stage! Valves give a particular type of sonic presentation that solid-state circuitry cannot replicate, and with vinyl it just sounds much more musical to me :)
Marco.
LOL. But with respect, Richard, none of that matters if you prefer the sound of valves to solid-state with vinyl. To me the best sound with vinyl I've ever had when using an MC cartridge has come from combining a well-designed quality all-valve MM phono stage with an MC step-up transformer that's been designed to match a particular cartridge, in my case the Denon DL-103 Pro and A23 step-up tranny.
No matter how good or how electrically 'correct' your active MC stage is it won't give me the sonic presentation of my valve phono stage! :)
Marco.
Oh dear! round and round in circles we go - just for one moment please listen - I am not challenging your preference for valves, this is not valve v transistor, this is transistor v transformer. I am talking about replacing the head amp function of the transformer and being done far more effective both musically and electrically. Just the function of the transformer. They were made before in the heyday of plastic, an example is the Ortofon MCA-76 moving coil head amplifier but it was bloody awfull and noisy. Now it can be done much better.
Richard, I understand your argument perfectly, and it makes sense. What I'm getting at is the real world application of your active MC stage in my particular system.
If I were to buy your active MC stage I would then have to bypass the valve MM stage in my Croft and use my 103 straight into your active MC design, wouldn't I? Therefore I would lose all the magical qualities of the Croft's valve MM stage, which under no circumstances I would ever want to do.
Do you see where I'm coming from now? :)
Marco.
Richard, I understand your argument perfectly, and it makes sense. What I'm getting at is the real world application of your active MC stage in my particular system.
If I were to buy your active MC stage I would then have to bypass the valve MM stage in my Croft and use my 103 straight into your active MC design, wouldn't I? Therefore I would lose all the magical qualities of the Croft's valve MM stage, which under no circumstances I would ever want to do.
Do you see where I'm coming from now? :)
Marco.
No, and you still do not see me!!!
I am not talking about my products, I am talking about principle. I do not even want to discuss my products as IMO it polutes my position here. I want to talk about design and music nothing more. You would lose none of your prefered distortion :) to do it my way, you would lose the transformers non linear nature and hum pick up. Anyway it is academic as to my knowledge there is no modern active head amp available. It would be very simple build project though for someone.
LOL. We're definitely going around in circles!
I'm not interested in "principles". I'm only interested in what makes my system sound best.
You would lose none of your prefered distortion to do it my way, you would lose the transformers non linear nature and hum pick up. Anyway it is academic as to my knowledge there is no modern active head amp available.
So you're talking about replacing my passive step-up transformer with an active one and using it with the valve MM stage in my Croft? That's a different ball game. I thought you were taking about replacing my valve MM stage with a totally separate active MC stage. Please correct me if I've got this wrong! :lol:
Well I've tried two active head amps in the past - the Ortofon you refer to, and a Graham Slee Elevator EXP. Both were significantly worse with my 103 than the A23 step-up tranny I currently use. I also get no hum.
Marco.
LOL. We're definitely going around in circles!
I'm not interested in "principles". I'm only interested in what makes my system sound best.
So you're talking about replacing my passive step-up transformer with an active one and using it with the valve MM stage in my Croft? That's a different ball game. I thought you were taking about replacing my valve MM stage with a totally separate active MC stage. Please correct me if I've got this wrong! :lol:
Well I've tried two active head amps in the past - the Ortofon you refer to, and a Graham Slee Elevator EXP. Both were significantly worse with my 103 than the A23 step-up tranny I currently use. I also get no hum.
Marco.
Good god! at last, man him understand words.
Then you agree with what I say, there isn't a modern good one available. BUTTTT the principle is op-amp technology is *potentially* far better at this job than transformersssss - fewwwww.
Do I have to build one to prove it.
Yes I'm glad we're getting somewhere now..!
Like I said before, the reason I use a step-up transformer and think they're better than active designs is because that's what I've heard - pure and simple. The two active designs I've tried recently have been shit in comparison. I cannot comment on something that I have no practical experience of using. I did use a battery powered Lentek head amplifier in the 80s, which was excellent with a Denon DL-103, but it's too long ago now to make any meaningful comparison to the A23 step-up transformer.
A modern active head amp may *potentially* be better but I would not call it better until I've heard it no matter how many "principles" or technical theories you throw at me to reinforce your argument! :eyebrows:
For me the proof of the pudding will always be in the listening. Go ahead and build something - I'm sure it would be interesting. Just don't expect me to buy it first in order to listen to it!! ;)
Marco.
anthonyTD
13-03-2008, 10:14
A bit too simplisitic, good as far as it goes, BUT the only gain function of a transformer is to exchange available current for voltage. How much current potential has a moving coil cartridge generated wiggling around on a piece of plastic, well not very much. So that derived voltage gain from the transformer is so weak it makes it over subject to loads of other viariables such as loading and hum characteristics and how it is used and connected. In reality a bag of nails. Now you can get it almost right but the overkill properties of the transformer involved make it enormously expensive, especially as you have to make the transformer as low loss as possible with exotic material winding / wiring and connection and masses of plate to keep up field strength.
Now thermal noise from active circuits is now capable of being taken incredibly low with modern op-amp technology and signal and noise floor relationships are still more to do with power supply and DC regulation than the gain characteristics of the circuit. As I have said before with valves active is no go so transformer is the *only* sensible option. With discrete or encapsulated modern op-amp circuits - no problem.
I agree, and i am totally for active m/c phono-stages using the best available solid state technology, but only when they have been designed correctly, and set up for the cartridge. valve circuits for very low output m/c are a definate no no in my opinion, on the other hand you can still build a very good valve phono-stage for m/m, and there are some very good m/m around these days...
I agree, and i am totally for active m/c phono-stages using the best available solid state technology, but only when they have been designed correctly, and set up for the cartridge. valve circuits for very low output m/c are a definate no no in my opinion, on the other hand you can still build a very good valve phono-stage for m/m, and there are some very good m/m around these days...
Thank you, you have me in complete agreement. MCs can be more trouble than they are worth, especially if you are clumsey or with little pokey fingers around the house.
Anthony,
on the other hand you can still build a very good valve phono-stage for m/m...
Yes indeed, and the MM stage inside the Croft is one of them! :)
You want to hear the difference in the phono stage now the Mullards are in!! :wow:
Marco.
MCs can be more trouble than they are worth
Because I don't make them I have no idea what "trouble" they are. All I know is that the all-valve MM stage in my Croft sounds absolutely superb, and its combination with the A23 step-up transformer/DL-103 Pro is sublime :)
So you can indeed get excellent results using MM valve stages and MC step-up transformers with moving coil cartridges. It's simply a matter of finding the right combination.
Marco.
Because I don't make them I have no idea what "trouble" they are. All I know is that the all-valve MM stage in my Croft sounds absolutely superb, and its combination with the A23 step-up transformer/DL-103 Pro is sublime :)
So you can indeed get excellent results using MM valve stages and MC step-up transformers with moving coil cartridges. It's simply a matter of finding the right combination.
Marco.
Duh!!! whats this got to do wiv what 'im an me wa talking a boot!
yer at it agin :scratch:
LOL. You're priceless! :lol:
When you said "MCs" I thought you were referring to MC phono stages not MC cartridges! I disagree with you that MC cartridges are more trouble than they're worth. Get it right and the sonic rewards are sublime.
The rest of the post was simply me agreeing with Anthony that there are some good MM valve phono stages around.
Marco.
anthonyTD
13-03-2008, 12:17
Thank you, you have me in complete agreement. MCs can be more trouble than they are worth, especially if you are clumsey or with little pokey fingers around the house.
something about the moving coil versus moving magnet debate, ie, which one is better? has always iritated me, when you examine how the both basic principals work, it would seem that modern well designed moving magnet cartridges should have the edge over most moving coils in terms of trackability anyway, i will explain, with the conventional moving coil cartridge you have the coils actually wound onto the end of the cantilever,hence you add mass to the part of the cartridge that needs to be as light as posible to track the record grooves acurately.
with modern moving magnet cartridges, the magnets are either mounted somewhere in the cartridge body, or are still fixed into the end of the cantilever but are so minute that their added weight is insignificant.
anthonyTD
13-03-2008, 12:25
something about the moving coil versus moving magnet debate, ie, which one is better? has always iritated me, when you examine how the both basic principals work, it would seem that modern well designed moving magnet cartridges should have the edge over most moving coils in terms of trackability anyway, i will explain, with the conventional moving coil cartridge you have the coils actually wound onto the end of the cantilever,hence you add mass to the part of the cartridge that needs to be as light as posible to track the record grooves acurately.
with modern moving magnet cartridges, the magnets are either mounted somewhere in the cartridge body, or are still fixed into the end of the cantilever but are so minute that their added weight is insignificant.
I should add that when i speak of moving magnet cartridges i am also including moving iron technology...
something about the moving coil versus moving magnet debate, ie, which one is better? has always iritated me, when you examine how the both basic principals work, it would seem that modern well designed moving magnet cartridges should have the edge over most moving coils in terms of trackability anyway, i will explain, with the conventional moving coil cartridge you have the coils actually wound onto the end of the cantilever,hence you add mass to the part of the cartridge that needs to be as light as posible to track the record grooves acurately.
That may be the case, Anthony, but I still prefer the sound of a good low-output moving coil. They're just much more musical to my ears. Unfortunately most are expensive though, apart from the DL-103 and perhaps an OC-9 or AT-33 PTG. You also have to amplify their (minute) signal correctly, which brings us to the previous argument! LOL.
The only MM cartridge I've (slightly) liked is the Shure V15 (later editions). The others I've heard sound 'shut in' and lacking in detail compared to a good moving coil. MCs, the one's I've used anyway, are much more open sounding and extended at frequency extremes and have a lovely 'liquid' sounding midrange that MMs lack - a bit like valve amplifiers compared to solid-state designs, actually! ;)
Marco.
Note though, that the one in the picture in your link shows 220V which should be fine for UK use, so how come you are mucking about with a step down transformer?
Yeah you'd think so, Mike. However my mate bought a Yaqin, someone plugged it straight into 240V, and the valves flashed. Fortunately the unit's internal fuse blew so no damage was done.
This is what can happen with the Chinese valves in place because they're shit. Do you want me to chance it with your Golden Dragons or Svets, or should I continue to use the step-down tranny just to be safe? ;)
Marco.
anthonyTD
13-03-2008, 19:47
That may be the case, Anthony, but I still prefer the sound of a good low-output moving coil. They're just much more musical to my ears. Unfortunately most are expensive though, apart from the DL-103 and perhaps an OC-9 or AT-33 PTG. You also have to amplify their (minute) signal correctly, which brings us to the previous argument! LOL.
The only MM cartridge I've (slightly) liked is the Shure V15 (later editions). The others I've heard sound 'shut in' and lacking in detail compared to a good moving coil. MCs, the one's I've used anyway, are much more open sounding and extended at frequency extremes and have a lovely 'liquid' sounding midrange that MMs lack - a bit like valve amplifiers compared to solid-state designs, actually! ;)
Marco.
an audio technica 440ML is one exceptionaly good M/M cartridge, at any cost.
its tracking capabilities have to be heard to be beleived, its also very dynamic, [perhaps a little too forward for some] i have one fitted in my old cranfield rock turntable [with original excalibur arm] and every time i play a record that shall we say is a bit worse for wear [excuse the punn] i am gob smacked at how well it plays... honestly this cartridge plays the last track on the record as good as the first, incredible!!!
Yes that's a good little cartridge - I noticed it on your T/T when I was at your place :)
Audio Technicas tend to be good all-rounders and offer high sound-per-pound value. Like you say they're superb trackers and are usually very well made. AT also make some very good headphones!
Marco.
Mmmm... nice mercury arc rectifier! ;)
More likely to be caused by the shitty Chinese power supply TBH!
Several folk on the WD forum have bought Chinese amps and found the power supplies crap to the point of being positively dangerous on some!
:oops:
I don't know if the power supplies are shitty. I think the ones in the Yaqin are actually pretty good. Perhaps Anthony could advise?
I take it then that the step-down transformer should remain in place when I have your valves in use? :lolsign:
Marco.
What does it step down from-to ?
Well, my house mains voltage is normally between 243 and 246V, so it'll step down from that to 220V, as it's been designed to do, I would imagine :)
So do we risk it or not? Personally, I think it will be ok, but as they're your valves it's only right that I ask first!
Marco.
Ah!....right.
For some reason or other I had the impression you'd got the 110V version. dunno why! :confused:
should be OK, try it with your valves first though :ner:
LOL. Scaredy cat! :lol:
No worries, but I'll have to wait until I receive some other KT88s I've ordered, which should be here any day. At the moment I only own the Chinese ones that came with the amp, and chances are they might pop without the step-down tranny.
Btw, the Golden Lions are sounding good. I put them in earlier this evening. In my system they have a very natural, musical sound with no emphasis on any part of the frequency range - they allow you just to relax and get into the music. This is an effect I like very much indeed. I don't think they're as good as original GECs, though, as claimed in the promotional blurb!
Svets will go in tomorrow or Saturday! :)
Marco.
To be certain, you'd need to measure your HT supply.
The data sheet (for original GEG KT88 at least) gives them a maximum rating of Va &Vg2 of 600V,with a typical operation for fixed bias (which I think yours is) of 550V(ish)
In the WD88 (mine) the anode voltage is around the 410V mark, so they're pretty unstressed. As yours 'claims' 60W (as opposed to my 35W) in ultralinear mode they are probably driven quite a bit harder, so I'd play it safe and use the tranny for now, unless you feel confident poking around a 500V DC supply with a meter!!!
The cryo Lion's are reckoned to take 70-100 hours to fully burn in and those a probably nearer to 50Hr mark, so there may be a bit more to come yet. They sound quite different to the Svet's with each having their strengths, but I'll let you make your own mind up as to what they are. Might be quite another 'kettle of fish' in your (obviously inferior :ner:) amp!
:smoking:
Mike,
The Yaqin is variable bias. I had to adjust the bias when the Golden Lions went in. There wasn't that much difference though compared to the Chinese Electron KT88s.
And I use the Yaqin in triode mode at 30 W.P.C. It sounds more musical that way than when it does set to ultralinear.
Marco.
'Variable bias' is 'fixed bias', somewhat confusingly!.... Meaning it has to be adjusted manually.
The other option is 'auto bias' (or self bias) also know as 'cathode bias'... Meaning no adjustment needed.
:lolsign:
Ok, Svets are in...
Initial impressions are very good, and I think that I prefer them to the GLs! They seem to be a bit more even-handed across the frequency range and have a more natural 'tone'. They also have a really big, open, sound and seemingly give more height and width to the soundstage. Music is very 'alive' sounding.
The GLs in comparison have a more pronounced midrange, slightly peaky, if truth be told, and a tendency to harden upper frequencies. In comparison to the Svet's their sonic balance is somewhat more 'contrived' and unnatural sounding. I don't think I'd be in a rush to import these from America... Both tubes have a nice tight tuneful bass, though, without excess warmth or 'bloom'.
My initial enthusiasm for the GLs has cooled somewhat. I think the reason I liked them so much last night was because they came in after the Chinese KT88s, and anything would be better than those!
I'll report back later once I've had a day's proper listening, and then swap them out for the GLs and see if my observations remain the same :)
Marco.
anthonyTD
14-03-2008, 10:10
Mmmm... nice mercury arc rectifier! ;)
Thanks shian, the picture was taken a few years ago in a friends bedroom!!!
Yeah nice avatar, Anthony. I was wondering what it was!
You have email, incidentally ;)
Marco.
Ok, Svets are in...
Initial impressions are very good, and I think that I prefer them to the GLs! They seem to be a bit more even-handed across the frequency range and have a more natural 'tone'. They also have a really big, open, sound and seemingly give more height and width to the soundstage. Music is very 'alive' sounding.
And they'll only get better as you 'put a few miles on the clock'! ;)
Indeed they are! :smoking:
One thing though, they bias very differently to the GLs. Did you find this or does your amp do it all for you?
One valve was showing 1.12V instead of the 0.58V I normally find is optimal (from the recommended range of 0.55V-0.6V) specified in the Yaqin manual, and the rest were all around 0.85V, so I had to reduce the bias substantially.
Anyway, they're sounding excellent. I'll report more later.
Marco.
I wouldn't know Marco, my amp is 'self bias'.
I'd expect 3 of them to settle down over a week or so as they're new, feel free to keep them till the end of the month and see how things go. One already has 25-30 hours on it so may be a bit different to the others for a couple of weeks. Let em all settle and see what you think then, they're cracking tubes TBH!
Cheers,
Mike.
Yeah they're fantastic, Mike.
At the moment they're totally outperforming the Golden Lions. The Chinese ones aren't even at the races!
I'm not sure the GLs are worth all the hype, but I'll give them ago again over the weekend now that I've got a handle on what the Svets are doing and see if my opinion changes.
Cheers for letting me keep them until the end of the month. This will ensure that I can assess them thoroughly :)
Marco.
I wouldn't know Marco, my amp is 'self bias'.
I'd expect 3 of them to settle down over a week or so as they're new, feel free to keep them till the end of the month and see how things go. One already has 25-30 hours on it so may be a bit different to the others for a couple of weeks. Let em all settle and see what you think then, they're cracking tubes TBH!
Cheers,
Mike.
P.S. I wouldn't put to much 'weight' on the Chinese 'manual', they are notorious for just copying things without a tremendous amount of understanding of whats going on. Trust your ears bud!!! ;)
Will do - as always.
Although the range quoted in the manual seems to be quite accurate. I've listened with them biased from 0.55V to 0.6V and found that 0.58V is optimal. If they're over-biased the sound becomes thick and heavy and if they're under-biased it becomes brighter and more brash - kind of like adjusting the VTF on a cartridge!
I'm lovin' this because apart from anything else it's broadening my experience further with hi-fi. I enjoy learning new things :)
Marco.
BTW!
While you're 'lovin' the learning curve, it might interest you to know that a good set of KT88's should last at least 2000 hours. Even in your evil, cobbled together, Hobgoblin of an amp! ;)
LOL. Noted :)
So now that I've outlined my thoughts on the GLs vs. the Svets what is your opinion of the differences? You've kept that one under your hat until now, so spill the beans! ;)
Marco.
Hi Mike (and others whom it may concern),
Today I tried the Yaqin straight into 240V without using the step-up transformer, and while it undoubtedly sounds better, IT IS NOT SAFE!!.
It was fine for an hour or so, but then fizz, pop, one of the capacitors blew... Nightmare eh? I always learn things the hard way! :lol:
The valves are undamaged though, and in fact were happily glowing away as the smoke was pouring out of the blown capacitor!!
Basically, the output transformers and valves are fine, but some components aren't up to coping with the extra voltage on the secondary circuit. I should have left it with the step-down tranny, but then I wouldn't have discovered the potential fire hazard for others in the UK using a Yaqin straight into 240V.
Fortunately it's nothing serious in terms of damage and Anthony from Tube Distinctions will be fixing it for me and upgrading it to be used safely with 240V, so I'll have it back shortly sounding better than ever :)
I'm sure Anthony will be along soon to offer his comments.
SO I WOULD WARN ANYONE IMPORTING A YAQIN KT88 VALVE AMPLIFIER FROM CHINA NOT TO USE IT WITHOUT HAVING THE UNIT PROPERLY CONVERTED TO UK VOLTAGE AND CHECKED OVER BY A QUALIFIED EXPERT!
Marco.
Marco!
May I draw your attention to:
More likely to be caused by the shitty Chinese power supply TBH!
Several folk on the WD forum have bought Chinese amps and found the power supplies crap to the point of being positively dangerous on some!
:oops:
And:
so I'd play it safe and use the tranny for now,
:ner:
anthonyTD
17-03-2008, 22:29
Hi Mike (and others whom it may concern),
Today I tried the Yaqin straight into 240V without using the step-up transformer, and while it undoubtedly sounds better, IT IS NOT SAFE!!.
It was fine for an hour or so, but then fizz, pop, one of the capacitors blew... Nightmare eh? I always learn things the hard way! :lol:
The valves are undamaged though, and in fact were happily glowing away as the smoke was pouring out of the blown capacitor!!
Basically, the output transformers and valves are fine, but some components aren't up to coping with the extra voltage on the secondary circuit. I should have left it with the step-down tranny, but then I wouldn't have discovered the potential fire hazard for others in the UK using a Yaqin straight into 240V.
Fortunately it's nothing serious in terms of damage and Anthony from Tube Distinctions will be fixing it for me and upgrading it to be used safely with 240V, so I'll have it back shortly sounding better than ever :)
I'm sure Anthony will be along soon to offer his comments.
SO I WOULD WARN ANYONE IMPORTING A YAQIN KT88 VALVE AMPLIFIER FROM CHINA NOT TO USE IT WITHOUT HAVING THE UNIT PROPERLY CONVERTED TO UK VOLTAGE AND CHECKED OVER BY A QUALIFIED EXPERT!
Marco.
These amplifiers offer good potential in terms of basic components, eg, casework, transformers,etc, but they are made to a cost, [PEANUTS] and unfortunetly one of the main parts, and "the most important part" that has been cost cut is the power supply, and components, ie, electrolytic capacitors! the problem when connecting these amps up to 240v instead of their intended 220v is not the mains transformer, its everything after it! the components they are using in these amplifiers are being run so close to their absolute maximum ratings on 220v, that just 20v or so more on the primary is enough to damage the power supply, and smoothing caps.
so, in my opinion, yes, these amps have the potential to be made into some thing much better than they are in standard form, but, my advice to anyone contemplating on purchasing one from for eg, ebay etc, is this, as soon as it arives, dont even plug it in!!! send it straight to an experienced valve technician to be checked, revalved, re-biased and to have at least the power supply capacitors and bridge rectifier diodes upgraded...
LOL, Mike. You don't learn anything though if you always play it safe! Well, that's the thought I'm consoling myself with now anyway... :lolsign:
Seriously though, what Anthony has said is 100% correct.
However, I would add that when used with a step-down transformer the Yaqin is absolutely fine and showed no signs of any problems when used in that context.
I do wonder though if Mr 'Yaqin UK' is doing anything to alter the suitability of the units used into 240V to customers he's supplying in the UK. If not there are liable to be a few fires!
Marco.
At least you 'learnt' that your amp sounded (is that a real word?) better (briefly!) without the step down tranny!
:lolsign:
Yes it did - and substantially so. If you're familiar with 'Naim parlance' I would equate the difference to that of going from a Hi-cap to a Supercap. Basically, it was the sort of audible difference one would normally associate with a significant PSU upgrade.
Apart from the increase in mains voltage, doing away with the 'gubbins' of the step-down transformer, and the associated cables and connections, would have had an impact on what was heard. In particular it meant that the Yaqin was getting the full benefit of my superb Transparent Reference powerlink mains cable instead of having to go through another cable interface from the step-down transformer.
Marco.
Oh christ!!!
DO NOT mention cables!!! :lolsign:
I know. We should all be using wet bits of string and some old bell wire...
Marco.
Blimey!...
Never mind the cables... have you seen all these 'slurp spiders'??? :stalks:
pure sound
18-03-2008, 08:05
These amplifiers offer good potential in terms of basic components, eg, casework, transformers,etc, but they are made to a cost, [PEANUTS] and unfortunetly one of the main parts, and "the most important part" that has been cost cut is the power supply, and components, ie, electrolytic capacitors! the problem when connecting these amps up to 240v instead of their intended 220v is not the mains transformer, its everything after it! the components they are using in these amplifiers are being run so close to their absolute maximum ratings on 220v, that just 20v or so more on the primary is enough to damage the power supply, and smoothing caps.
so, in my opinion, yes, these amps have the potential to be made into some thing much better than they are in standard form, but, my advice to anyone contemplating on purchasing one from for eg, ebay etc, is this, as soon as it arives, dont even plug it in!!! send it straight to an experienced valve technician to be checked, revalved, re-biased and to have at least the power supply capacitors and bridge rectifier diodes upgraded...
Hi Anthony, Are they trying to use single electrolytic capacitors to cover a 500+ volt rail?
Hi Guy,
You have a PM :)
Marco.
anthonyTD
18-03-2008, 10:04
Hi Anthony, Are they trying to use single electrolytic capacitors to cover a 500+ volt rail?
yes,and its shamefull, but thats the chinese for you...
pure sound
18-03-2008, 11:03
Oi! Don't tar them all with the same brush! The amps I sell have series connected 400v caps with bleed resistors across each. That works perfectly well & safely:)
anthonyTD
18-03-2008, 14:21
Oi! Don't tar them all with the same brush! The amps I sell have series connected 400v caps with bleed resistors across each. That works perfectly well & safely:)
my apologies, i should re-phrase, what i was trying to get over was, the chinese have become very good at making things to a cost, and i agree, when they want to make something good, they are as capable as any.. the problem is the world has gotten used to getting the latest technology especially from china for very little money, but, as demand for all this technology keeps rising, then the price of the raw materials will keep rising, so my point is compromises will still be the norm in the majority of equipment coming in from china...
there, is that better!!!
anthonyTD
18-03-2008, 14:49
Quite true Anthony. You either have to have people sitting on production lines over there doing the QC as production happens or otherwise apply 100% QC on what comes here when it arrives.
exactly!!!
Hey Marco,
Is your amp working again yet? I was wondering how you're getting on with the Svet's?
Cheers,
Mike.
Hi Mike,
The amp went off to Mark at TD today, so when he gets it tomorrow and phones me with details of the repair, I'll update you.
The Svets are fine, but obviously I'm not using them at the moment as I have no amp.
Marco.
The Yaqin will be collected from Anthony's place on Monday, fully repaired and with a few 'tweaks' having been carried out ;)
I'll report on how it performs probably on Tuesday, as Monday will be a busy day on the road and with one thing or another.
Stay tuned!
Marco.
Is it mended ?
:)
Jeez, that's freaky! You must have been thinking about that just as I was typing it! :eyebrows:
Marco.
Ah!.. I see that it is!
Jolly good.
Ok, I thought I'd post a quick update on the Yaqin/tube-rolling situation.
First of all, the Yaqin is now in my possession back from being repaired at Anthony's, and I've been listening to it for most of the day.
Anthony has replaced the cheap Samsung capacitors with high-grade Panasonic ones, replaced the existing tiny (low quality) bridge rectifiers with, I believe, high-grade ones of his own design (correct me if I'm wrong here, Anthony!), and a few other bits and pieces which I'm sure Anthony will be able to comment on in more detail. I have also purchased a matched quad of brand new cryo-treated Svetlana KT88s.
I had a quick listen last night when I got back from Mid Glamorgan for a couple of hours or so and it was obvious that the performance of the Yaqin had increased quite significantly, however nothing compared to what I'm experiencing now... :wow:
Frankly the difference is astonishing - and this considering that no 'major' modifications have been carried out such as the output transformers or power supplies replaced, point-to-point wiring, etc!
The sound from the Yaqin now has incredibly wide stereo separation and superior dynamic range, with every nuance of the music seemingly suspended in its own acoustic space and projected into the room with haunting realism. Musical 'communication' has been notably enhanced, and timing is so spot on that performances have a rhythmic accuracy that enables one to completely suspend disbelief and perceive a live band playing in front of the speakers - amazing stuff!!
Tonally, everything sounds much more 'natural' with little emphasis on any part of the frequency range - gone is a slightly brash quality and presentation that previously was somewhat impressive in a 'hi-fi' sense but less so in terms of musical coherence. Bass, though, is more tuneful and has greater authority. Furthermore, I am now able to listen to the amp on ultra-linear mode and take advantage of its full 60 W.P.C, whereas before I was forced to use it on triode mode to soften the rough edges caused by the circuit that previously ultra-linear mode ruthlessly revealed.
So all-in-all I've achieved a significant improvement in performance for a relatively small outlay. My thanks go to Anthony of Tube Distinctions for his excellent work and expertise. Goodness knows how much more is to come when I eventually carry out the major modifications to the amp as previously outlined..!
As far as the cryogenically-treated Svetlana KT88s are concerned, there is absolutely no doubt that these are much superior to the standard untreated ones. I shall go into more detail about this tomorrow, as I have been doing some extensive comparisons with various valve types, but safe to say that the cost difference of having valves 'cryo-d' is more than justified.
Right, I'm going back to listen some more and rediscover my music collection :smoking:
(Much) later, people...
Marco.
Filterlab
01-04-2008, 21:33
...Right, I'm going back to listen some more and rediscover my music collection...
Now that's a sign of a good upgrade, that and he fact that you've hardly been on which means you must be enjoying your hi-fi.
Top stuff mate. :)
Oh it's good all right, baby :smoking:
Didn't get to bed until 3am!
Marco.
Filterlab
02-04-2008, 08:53
Cool stuff, I take it you live in a detached house then.
Indeed we do, but I wasn't listening loud. Del was asleep next door :smoking:
I tend not to listen to music loud when I'm on my own anyway - that's a bit bonkers :eyebrows:
Marco.
anthonyTD
04-04-2008, 08:28
Ok, I thought I'd post a quick update on the Yaqin/tube-rolling situation.
First of all, the Yaqin is now in my possession back from being repaired at Anthony's, and I've been listening to it for most of the day.
Anthony has replaced the cheap Samsung capacitors with high-grade Panasonic ones, replaced the existing tiny (low quality) bridge rectifiers with, I believe, high-grade ones of his own design (correct me if I'm wrong here, Anthony!), and a few other bits and pieces which I'm sure Anthony will be able to comment on in more detail. I have also purchased a matched quad of brand new cryo-treated Svetlana KT88s.
I had a quick listen last night when I got back from Mid Glamorgan for a couple of hours or so and it was obvious that the performance of the Yaqin had increased quite significantly, however nothing compared to what I'm experiencing now... :wow:
Frankly the difference is astonishing - and this considering that no 'major' modifications have been carried out such as the output transformers or power supplies replaced, point-to-point wiring, etc!
The sound from the Yaqin now has incredibly wide stereo separation and superior dynamic range, with every nuance of the music seemingly suspended in its own acoustic space and projected into the room with haunting realism. Musical 'communication' has been notably enhanced, and timing is so spot on that performances have a rhythmic accuracy that enables one to completely suspend disbelief and perceive a live band playing in front of the speakers - amazing stuff!!
Tonally, everything sounds much more 'natural' with little emphasis on any part of the frequency range - gone is a slightly brash quality and presentation that previously was somewhat impressive in a 'hi-fi' sense but less so in terms of musical coherence. Bass, though, is more tuneful and has greater authority. Furthermore, I am now able to listen to the amp on ultra-linear mode and take advantage of its full 60 W.P.C, whereas before I was forced to use it on triode mode to soften the rough edges caused by the circuit that previously ultra-linear mode ruthlessly revealed.
So all-in-all I've achieved a significant improvement in performance for a relatively small outlay. My thanks go to Anthony of Tube Distinctions for his excellent work and expertise. Goodness knows how much more is to come when I eventually carry out the major modifications to the amp as previously outlined..!
As far as the cryogenically-treated Svetlana KT88s are concerned, there is absolutely no doubt that these are much superior to the standard untreated ones. I shall go into more detail about this tomorrow, as I have been doing some extensive comparisons with various valve types, but safe to say that the cost difference of having valves 'cryo-d' is more than justified.
Right, I'm going back to listen some more and rediscover my music collection :smoking:
(Much) later, people...
Marco.
As i have always said, the power supply is the most important part of any piece of audio equipment, needless to say its the first part that should be looked at when seeking upgrades.
the original capacitors were changed for low esr, panasonic type, also they are the high temperature type [105c] because they run warm in this paticular amp due to where they are situated. next was to get rid of the nasty tiny bridge rectifiers and make up some of my own using ultra fast soft recovery types. some other parts were substituted eg, bleed resistors,etc, also, the suppresor cap was removed from the primary of the mains transformer.
last but not least, a new matched quad set of svetlana cryo-treated KT88 were fitted, and biased [properly] and apart from re-doing some of the bad soldering etc, that was about it for the first upgrade, but its a significant upgrade in sonic terms as it now enables the amp to be used in ultra-linear operation which is the best [ and most powerfull] mode to demonstrate :eyebrows:to the listener what this amp is potentialy capable of...
Anthony,
Hi, sounds interesting, would you mind casting an eye over the schematic of mine sometime and seeing if there are any recommendations you'd like to make? :)
Marco,
Any chance of a pic of it's modded inards?... Also, I see it's not actually a power amp but an integrated! You might like to consider removing the input switching and modifying the volume control to work in 'shunt mode' (or doing away with it altogether)? Cheap 'n easy upgrade of the 'no-brainer' type! ;)
Cheers,
Mike.
P.S. - Still no sign if those tubes matey!
Pics will have to wait, Mikey, until some techie chap (with a camera) has the lid off again. This will probably be Anthony in about a couple of months time! :eyebrows:
Right now the Yaqin is squeezed into a modified 2-tier Mana rack, at Phase 17, so it's going nowhere!
Point taken regarding the input switching, etc. That will be attended to when Anthony carries out the next set of modifications, and upgrades the PSU, output transformers, etc :)
It sounds absolutely stunning now, btw.
Marco.
P.S The valves have taken the 'scenic route' to you, I fear ;)
Right now the Yaqin is squeezed into a modified 2-tier Mana rack, at Phase 17, so it's going nowhere!
Phase 17 indeed! Pillock! :lol:
:eyebrows:
LOL. You don't know the half of it, mate. You wanna see my mains set-up!! :mental:
:lol:
Marco.
anthonyTD
05-04-2008, 09:39
Anthony,
Hi, sounds interesting, would you mind casting an eye over the schematic of mine sometime and seeing if there are any recommendations you'd like to make?
hi mike,
yes, certainly i will do that.
anthony...
Ok, valves first...
Mike sent me four ECC83-type valves to try:
1) Mullard CV-4004
2) CV-493 military spec 12AX7
3) Golden Dragon ECC83
4) A 'mystery' valve ;)
Everyone raves about the CV-4004 as being the best Mullard (or ECC83) there is, and I have to admit for that reason I wanted to buy the CV-4004 from Mike there and then, however that's not quite how it panned out...
One of the things I've learned so far with valves (and I've learnt quite a lot over the last couple of months with experimenting) is that NOS valves always sound better than modern valves - they just have a much more natural sound. Modern valves tend to exaggerate frequency extremes one way or the other and consequently have a more 'mechanical' kind of presentation. This is why I've gone the extra mile to kit-out the Croft with NOS Mullard ECC83 and 35s.
But, and this is the crucial thing, it's not just a matter of obtaining any NOS valves, the performance varies depending on the vintage. 50s and 60s NOS valves, for example, sound different from 70s or 80s ones, and what I've discovered is that there is nothing to beat the sound of the earlier valves from the 50s and 60s. They used different materials and processes in their production that are now illegal, and this is why they have such a unique sound. A while back Anthony sold me a 1950s Mullard ECC83 and this is what I use as my benchmark to compare equivalent valves against.
In that respect I tested the ones Mike sent me against the 1950s Mullard and quite simply none were better than it, not even the CV-4004. The results in order of performance were as follows:
1) 1950s Mullard ECC83
2) CV-4004
3) The 'mystery valve'
4) CV-493 military spec
5) Golden Dragon ECC83.
The CV-4004 is very good, but lacks the 'magic' of the 1950s Mullard. It sounds great until you hear the 1950s Mullard, which simply has a broader and more neutral tonal palette and a musical coherence that all the other valves lacked. The mystery valve was also good, but had a slightly 'processed' quality compared to the 1950s Mullard and CV-4004, and a touch more 'grain'. The CV-493 was pretty good but compared to the best here had a slightly dull sounding character and appeared to overemphasise bass notes somewhat. The Golden Dragon was really quite disappointing and was bright and brash sounding in comparison to the rest.
So there you have it - 1950s valve technology wins! :)
As for the digital cable Mike sent me, I haven't finalised my decision yet as I'm a firm believer that cables need to run-in for a period of time before you can analyse their performance effectively, so as I want to give his cable a fair chance I will come to a definitive conclusion about its performance in a few days.
As this post is mainly about valves I will move the valve-related content to my 'tube rolling' thread in the D.I.Y room later. The bit about the digital cable will remain here.
Marco.
Ha!... There you go!
Told ya not to get too hung up on the CV thing. ;)
What they do on a tester does not necessarily translate to what they sound like.
By the way, a CV4004 isn't strictly speaking an ECC83, it's an M8137, like THIS (http://www.tubecollector.org/cv/cv.php) (type in CV4004 - near as damn it the same thing though).
Now then, care to guess the vintage and price of the 'mystery valve'? :eyebrows:
Cheers,
Mike.
I may be teaching grandmothers to suck eggs here, but remember that CV is the UK version of VT, it was introduced during the war to rationalise and standadise the huge pre war selection of valves from many makers, so a particular CV492 could have been made by any of the companies and factories that were producing ecc83/12ax7 and the fact it was numbered CV doesn't mean they changed how they were made.
Also, have you tried 5751s as ecc83 replacements, a bit less gain, but nice sounding (IMHO)
Hi Nick,
Good to see you posting now - please don't be 'shy' in future ;)
I'm sure Anthony and you will have much in common :)
Thanks for the info on the CV rating - noted. I'm fast becoming a total valve anorak :lol:
However, sadly, I have to admit to finding all this stuff quite fascinating. I've not tried 5751s. How would you say they compare in sound to a Mullard ECC83 of similar vintage?
Marco.
Ha!... There you go!
Told ya not to get too hung up on the CV thing.
What they do on a tester does not necessarily translate to what they sound like.
By the way, a CV4004 isn't strictly speaking an ECC83, it's an M8137, like THIS (http://www.tubecollector.org/cv/cv.php) (type in CV4004 - near as damn it the same thing though).
Now then, care to guess the vintage and price of the 'mystery valve'?
I would say almost certainly it's a new valve, probably of Russian or American origin. Cost? No more than £8 (or the equivalent in Dollars, etc) :)
You're absolutely right that: "what they do on a tester does not necessarily translate to what they sound like" and I now understand why. However, it also shows that even though I was influenced by the CV thing it didn't skew the results. My ears still told me that the 1950s Mullard was best - so much for 'expectation bias', eh? ;)
I'll remember this particular experiment next time I'm in a debate with a belligerent cable sceptic :eyebrows:
Marco.
However, sadly, I have to admit to finding all this stuff quite fascinating. I've not tried 5751s. How would you say they compare in sound to a Mullard ECC83 of similar vintage?
Well, I have only tried them myself in simple phono stages. To my ears they have much of the qualities of the mullard, but less of the slightly overbearing forward mid. Slightly less gain, so that may be a problem for some.
Btw, I checked that the RIAA response was the same before comparing the sounds. Often in a phono much of the difference can be down to differing Ra of the valve (often increased if the valve has been used in the past) altering the RIAA equalisation.
Hi Nick,
Well, I have only tried them myself in simple phono stages. To my ears they have much of the qualities of the mullard, but less of the slightly overbearing forward mid.
Interesting.
I can't say I've found that at all - in fact quite the opposite! :)
Mullard ECC83s (and in fact all Mullards) sound the most neutral to me of any valves I've heard so far, and I've heard a few, although certainly not them all or as many as you're likely to have heard.
Which ones would you suggest then that have all the Mullard qualities but without, in your opinion, the "overbearing forward mid"?
I wouldn't want to lose any gain, though, as in my experience lower gain often makes for a softer sound. I like just the 'right' amount, not too much or not too little. Lack of gain is something that infuriates me with certain active MC phono stages. It's one of the reasons I use a step-up transformer into a valve MM stage. I like to achieve the same listening level on the volume pot as I do with CD. I don't doubt though that 5751s sound great in the right circuit.
Btw, I checked that the RIAA response was the same before comparing the sounds. Often in a phono much of the difference can be down to differing Ra of the valve (often increased if the valve has been used in the past) altering the RIAA equalisation.
Yes I don't doubt that would be the case.
Marco.
I like GE 5751s, The difference to the Mullard is very slight, I may have over described the difference, but I think its there. I guess it depends on your overall system balance as well.
They can also be very cost effective as they are not so widely sought after as the equivilant NOS 12ax7
I agree entirly about the importance of the gain structure of the system. one hing I have noticed is that using a MC cart into a valve phono without a step up can at first sound rather nice, but its a false sound, almost like analog dither.
I also agree about the quality of Mullards, you should talk to Steve in a couple of weeks about the info he has on the Mullard production process (esp pre Phillips), and how they controlled every step from smelting the ore onewards. Problem is, because everyone wants Mullards you can find well used examples described as NOS, and even rebadged ones.
Hi Nick,
I agree that it depends on the overall system balance. I reckon mine is pretty neutral - it's certainly been tailored that way in purpose, and is one of the reasons I'm able to detect subtle difference between valves and cables quite easily.
If someone's got some GE 5751s at Owston I'll give them a go :)
I've asked Steve to bring some valves along already.
Getting the 'gain structure' right, as you refer to it, is crucial, particularly in phono stages. The amount of flat and lifeless phono stages I've heard because of insufficient gain is incredible, and not all of them were cheap! The worst offender, although not expensive, were the old Naim phono boards, where you used to have to adjust a NAC52 to about 12.15 on the dial to get decent volume on phono! The Prefix was no different, although their new phono stage has addressed this issue. I found the Graham Slee Reflex/Elevator EXP combination also a bit like this, and strangely that was with using an active head amp as part of the combo. There are plenty of others too I've used that have sounded limp and dynamically restrained because of insufficient gain. The only active MC stages I like are those with adjustable gain, loading and impedance. The fixed ones are generally crap unless they've been designed with a particular cartridge in mind.
Strangely this sort of thing is considered normal by many people. Significant loudness differences between CD and phono is not normal or indeed correct. If the gain structure (I like that word!) is right listening levels between phono and CD should be almost identical. With the step-up transformer I can switch between both inputs and with very little adjustment of the volume control achieve the same listening level. The gain on phono is slightly less but not much.
I will definitely talk to Steve about Mullards. It sounds like a fascinating subject to discuss over a few beers and some pork scratchings, or whatever (not that I eat pork scratchings but you get my point :eyebrows:) :cool:
Ian Walker will be coming too, incidentally. He's looking forward to meeting you again.
Marco.
I would say almost certainly it's a new valve, probably of Russian or American origin. Cost? No more than £8 (or the equivalent in Dollars, etc) :)
Spot on!... It's a current production Chelmer, I don't remember the exact price but certainly under a tenner. I think it's pretty good. Some retailers want £60+ for a Mullard CV4004, and I don't think they're six times better than the Chelmer.
If someone's got some GE 5751s at Owston I'll give them a go :)
Where/when is 'Owston' ??? :scratch:
Cheers,
Mike.
Being a WD forum regular you must know about the 'eggfests'! Groups of mad valve aficionados meet up and demonstrate each others designs at a local pub in Doncaster. See here:
http://www.pubsgalore.co.uk/pubs/33873/
It's being held on 19th & 20th April. Do you fancy tagging along? I'll be bringing my Yaqin, amongst other things, so you can come and have a laugh at it :lol:
Marco.
P.S Aren't Chelmer British? If so, I got that bit wrong, and no, a CV-4004 is definitely not six times better.
Eggfest is held at Eggborough ya big Muppet! (theres a clue in the name :ner:) :lolsign:
Here: http://maps.google.co.uk/
I might make it to Doncaster as it would be easy for me (I have familily there) but I think I'm on-call that weekend. :(
I'll check on Monday.
P.S. Hmmm.... stupid link doen't work, sorry.
The first ones were held in the Social Clum of the Eggborough Power station. Much fun was had by all. But the problesm were the main room was the dance floor, so it was more than a problem to demonstrate a 1W SET through front loaded horns. So Steve (who organised the Eggfests) set out to find a smaller venue that didnt require driving a room the size of a barn. Doncaster is the best he has found so far. And like Eggborough has the advantage of a attached bar, and now runs over two days instead the Eggborough one.
Here is a video from a earlier Eggfest of Paul Barker and myself (the fat hairy one) seeing just how far you can push a gm70.
http://www.zippyvideos.com/9880518285346786/ef_3_vid_3/*ngibbons
Ah!....
So these are one and the same events then? :) (more or less).
It's a wee bit further for me to travel (but not that much) and accommodation is even easier for me!
On-call permitting, I may well be there.
Cheers,
Mike.
P.S. Nick, I have 'questions' for you!!! :scratch:
I like questions, as long as you reaslise I may not have an answer, and if I do, it may be tosh.
:-)
Eggfest is held at Eggborough ya big Muppet! (theres a clue in the name :ner:) :lolsign:
Hehe... How would I know? I've never heard of Eggborough (or been there)!
I thought the 'eggfest' thing was maybe because there were loads of egg sandwiches served, or some shit like that :lol:
Marco.
I like questions, as long as you reaslise I may not have an answer, and if I do, it may be tosh.
:-)
Ha!.... I think not Sir.... This schematic has your name all over it. Literally! ;)
Something I meant to ask... Can you buy a cheap, portable, valve tester from the likes of Maplins?
I would like something like this to test valves at audio fayres, car boot sales, etc, before buying. Or can you only get those big professional things that Mike posted a picture of recently?
Cheers.
Marco.
anthonyTD
12-04-2008, 10:33
Also, have you tried 5751s as ecc83 replacements, a bit less gain, but nice sounding (IMHO)
i agree,
5751's are a very good sounding valve, the gain, [depending on the circuit and voltage applied] is around the same as a 12AY7, which sadly is also very scares,hence amplification is around 70, as aposed to an ECC83/12AX7 which is 100.
so, not too low. as for the chelmer valve [mike] they are a british company, but their valves are just rebranded,new production, ie, Chinese, Russian, Czech.
anthony,TD...:gig:;)
Sounds intriguing. But I would need to listen to one in the Croft, and compare it to the 1950s Mullard ECC83 to see if the lower gain was an issue.
I'm going to see if I can get some of those Mullard 'long plates' ;)
Marco.
What are people's views on this:
http://www.vacuumtube.com/toppage31.htm
I was going to buy one if our resident experts thought it was any good. Or perhaps you have other suggestions? :)
I'd like to be able to test valves myself rather than having to rely on others.
Marco.
as for the chelmer valve [mike] they are a british company, but their valves are just rebranded,new production, ie, Chinese, Russian, Czech.
Yep, I'm pretty sure(ish) that it's of Russian origin. It's been a while since any valves have been produced in the UK (I think?).
Cheers,
Mike.
Hey Marco...
Considering your new found interest in valves maybe you should dowload this:
http://www.pmillett.com/Books/intro_RDH4.pdf
Be careful though.... It can seriously hurt your head! :scratch:
Loads more downloadable interesting stuff here too:
http://www.pmillett.com/technical_books_online.htm
Enjoy! :lolsign:
Cheers,
Mike.
Yeah, I thought it looked like an Electro-Harmonix/Sovtek type.
Marks out of 10 then, daddy? :smoking:
Marco.
Considering your new found interest in valves maybe you should dowload this:
http://www.pmillett.com/Books/intro_RDH4.pdf
That might be a little like being thrown in at the deep end with a paving slab tied to you leg.
Maybe a copy of Morgan Jones would be a better place to start, or Rozenblitz, but that depends if you want to agree with Rozenbliz.
The valve tester looks a nice thing, but you can buy a lot of valves for £500.
That's what I was thinking, Nick, but I would like one.
Do they have to be so elaborate, though?
I was wondering whether some talented chap could lash-up a home-made one that would do the job? It's doesn't have to look great, just as long as it's functional and reasonably accurate :)
Marco.
That might be a little like being thrown in at the deep end with a paving slab tied to you leg.
Absolutely! :lolsign:
Yeah, I thought it looked like an Electro-Harmonix/Sovtek type.
Marks out of 10 then, daddy? :smoking:
Marco.
9.8 matey! :)
What did I lose the .2% for? Not washing my bollocks this morning? :lolsign:
Marco.
Marco,
I would recommend the Rozenblit book 'Beginners Guide to tube Audio Design' I found it very usefull when I first started out.
He also makes a tube analyser kit if you fancy getting your fingers burnt....
http://www.transcendentsound.com/tube_analyzer.htm
What did I lose the .2% for? Not washing my bollocks this morning? :lolsign:
Marco.
Arrrgghh!.... Too much information!
:sofa:
0.2 out of 10 is 2% BTW. ;)
Indeed! Too much vino today with my pasta :drinking:
Neal,
I like the look of that tester. I'd be hopeless at building one, though. How about I buy the kit and I pay one of you chaps to build it?
Don't all volunteer at once now :lol:
Marco.
Yeah I like the look of it too! :)
Here's an idea. You buy the kit Marco and I'll build it and keep it. :lolsign:
Somewhat strangely, I'm not 100% liking that idea...
If you handle the solder burns, though, you'll be amply rewarded ;)
Marco.
Somewhat strangely, I'm not 100% liking that idea...
If you handle the solder burns, though, you'll be amply rewarded ;)
Marco.
Somehow I had a 'feeling'. :)
If you really want one building though, go ahead! Just don't expect it thrown togther in 10 mins. ;)
Ok I'll take you up on that one, Belinda :eyebrows:
It won't be right now though as I have other priorities. But I'll save the details Neal posted and give you a shout when the time is right :)
Marco.
I may be teaching grandmothers to suck eggs here, but remember that CV is the UK version of VT, it was introduced during the war to rationalise and standadise the huge pre war selection of valves from many makers, so a particular CV492 could have been made by any of the companies and factories that were producing ecc83/12ax7 and the fact it was numbered CV doesn't mean they changed how they were made.
I told him the same thing (more or less), but he's still 'keen'! :eyebrows:
Also, have you tried 5751s as ecc83 replacements, a bit less gain, but nice sounding (IMHO)
I've been looking into these little fellas with some 'interesting' results:
http://cgi.ebay.co.uk/nos-sylvania-5751_W0QQitemZ280216439113QQihZ018QQcategoryZ39997 QQssPageNameZWDVWQQrdZ1QQcmdZViewItem :scratch:
Strangely, there are no bids!
Watford Valves has Philips and GE 5751s at £16 and £20.
Well, I picked up some nice valves at the Owston meeting from Steve S.
4 x 1950s NOS US Navy-branded RCA 6SN7s in original boxes, which have replaced new stock Electro Harmonix 6SN7s in the Yaqin, 2 x Mullard ECC35s, to complete my set of 5 for the Croft, and some superb NOS 1950s Telefunken ECC83 'long plates', which are now without doubt the best ECC83s I've heard, just edging out my 1950s Mullard. I am using them in the Croft and the Yaqin. The RCA 6SN7s are bloody good, too.
The valve compliment in the Yaqin is now 2 x NOS Telefunken ECC83 (as above), 4 x NOS RCA military spec 6SN7s (as above) and 4 x matched quad of cryo'd Svetlana KT88. Not bad. All I need now is 4 x 1950s NOS GEC KT88s to complete my 'ultimate' valve line-up for the Yaqin, which will happen sometime before the end of the year (or sooner). I'd perhaps also like a matched quad of ECC32 'Coke bottles', but I'm not sure how much of an improvement they'd be over the 1950s RCA 6SN7s.
All-in-all the new valves give a significant improvement in performance. There's nothing to beat top-notch NOS valves. The new stuff is just not in the same league. My thanks go to Steve for looking them out and measuring them all! Nice one, dude :smoking:
Marco.
anthonyTD
20-04-2008, 21:58
Well, I picked up some nice valves at the Owston meeting from Steve S.
4 x 1950s NOS US Navy-branded RCA 6SN7s in original boxes, which have replaced new stock Electro Harmonix 6SN7s in the Yaqin, 2 x Mullard ECC35s, to complete my set of 5 for the Croft, and some superb NOS 1950s Telefunken ECC83 'long plates', which are now without doubt the best ECC83s I've heard, just edging out my 1950s Mullard. I am using them in the Croft and the Yaqin. The RCA 6SN7s are bloody good, too.
The valve compliment in the Yaqin is now 2 x NOS Telefunken ECC83 (as above), 4 x NOS RCA military spec 6SN7s (as above) and 4 x matched quad of cryo'd Svetlana KT88. Not bad. All I need now is 4 x 1950s NOS GEC KT88s to complete my 'ultimate' valve line-up for the Yaqin, which will happen sometime before the end of the year (or sooner). I'd perhaps also like a matched quad of ECC32 'Coke bottles', but I'm not sure how much of an improvement they'd be over the 1950s RCA 6SN7s.
All-in-all the new valves give a significant improvement in performance. There's nothing to beat top-notch NOS valves. The new stuff is just not in the same league. My thanks go to Steve for looking them out and measuring them all! Nice one, dude :smoking:
Marco.
well done!!!;)
Yep I'm well pleased, mate. Every time I try NOS valves it hammers home just how much better they are. It's a pity that stocks will eventually run out :(
The bonus is though that good ones last for ages! :)
Marco.
Marco,
Have you finished with those ECC83's yet mate?.... I have a 'job' for them! ;)
No worries, dude. I'll pop them in the post tomorrow :)
Where have you been? You've been a bit quiet the last few days.
Marco.
Been working, I've been on-call the last few days.
Do me a favour though, send them to my HOME address this time will ya! :lolsign:
Hehe, I was going to say that but I thought I'd let you intervene ;)
It's on the box the valves came in, I think. I presume this time it's the right one? :lol:
PM me your full postal address just to make sure!!
Marco.
Marco,
Do you remember the Telefunken ECC803S mentioned earlier in this thread?
Here's a link to one for sale. HAVE A STIFF DRINK BEFORE LOOKING !!! ...... You have been warned! :drinking:
http://cgi.ebay.co.uk/ECC803S-TELEFUNKEN-VALVE-TUBE-NEW-1-PC-PT_W0QQitemZ280218862287QQihZ018QQcategoryZ39997QQ rdZ1QQssPageNameZWD1VQQcmdZViewItemQQ_trksidZp1638 Q2em118Q2el1247
Cheers,
Mike.
Filterlab
25-04-2008, 13:50
WOW! Nice valve, £455 though!
There's been award winning integrated amps for less than that!
LOL - interesting. That's just stupid money, though. The value of these sorts of valves is based mostly on rarity to collectors who nine times out of ten won't use them anywhere near audio equipment!
I'm only interested in out-and-out performance for audio use. I suspect the difference sonically will be minimal compared to the 1950s Telefunken ECC-83 'long plates' I have. I couldn't care less how rare something is or if the name has been rubbed off the glass. I don't 'collect' valves like stamp collectors collect stamps! :eyebrows:
Marco.
By all accounts the Tele 803s IS the dogs bollocks as far as this type of tube is concerned. The value is not based entirely on rarity!
I'll never know how good they are at those prices though!!!
I had a 'smooth plate' (long), didn't like it as much as the Mullard's, so I ebayed it and got £40. Not a lot, but at least it was a fifteen quid profit. Which was nice. :)
anthonyTD
25-04-2008, 19:44
By all accounts the Tele 803s IS the dogs bollocks as far as this type of tube is concerned. The value is not based entirely on rarity!
I'll never know how good they are at those prices though!!!
I had a 'smooth plate' (long), didn't like it as much as the Mullard's, so I ebayed it and got £40. Not a lot, but at least it was a fifteen quid profit. Which was nice. :)
mike,
ill send you a couple over for you to try...:eyebrows::eyebrows:
Well, Mike, I promise I'll find a Tele 803, and compare it to other ECC83s. We'll see what all the fuss is about, and trust me I won't be paying that price for it ;)
When you say "smooth plate" do you mean the Tele "long plate" ECC83s I've got? If so, we'll have to differ. In my system, they were quite a bit better than either the Mullard 'short plates' or 'long plates', no matter the era - yes I listened to both at Owston before buying the Tele 'long plates' :)
The Teles simply had less of a pronounced sonic signature, particularly in the midrange, and just sounded 'right' - previously a trait I valued very much in the Mullards, but the Tele 'long plates' just do it much better!
However, results will undoubtedly vary from system to system. There's no such thing as the 'perfect' valve for every system.
Marco.
mike,
ill send you a couple over for you to try...:eyebrows::eyebrows:
If you've got some 803s I'm on first dibs!!
Admin and current customers get priority :lol:
Marco.
anthonyTD
25-04-2008, 19:52
mike,
ill send you a couple over for you to try...:eyebrows::eyebrows:
when i get some!:lol::lol::lol::eyebrows:
LOL. Are you ordering some in like?
Marco.
If you've got some 803s I'm on first dibs!!
Admin and current customers get priority :lol:
Marco.
Kiss my ass! :ner:
You get 'first dibs' when you know how to use a soldering iron Monkey Boy! :trust:
Seriously though..... They can't be worth that much.
Footballer and Movie Star incomes aside!
:mental: :mental: :mental:
BTW... 'long plates' means nowt mate. 'Smooth Plates' are where its at boyo! :ner:
Yes, I bet you've got a very 'smooth plate' with all that rubbing you do! :lol:
There's no hairs on your palms, I bet, boy ;)
:eyebrows:
Marco.
Filterlab
26-04-2008, 10:54
...collectors who nine times out of ten won't use them anywhere near audio equipment!....
You see, now that's just a waste. Like a supercar that spends it's entire life under a cover in a garage, things are made to be used and enjoyed.
Indeed. Apparently Chinese businessmen like to 'display' them in their offices in illuminated glass cabinets so they can, erm, sit and 'look at them'... :scratch:
The mind boggles!
Marco,
The Yaqin will be ready for modifying further in a few weeks. The plan is to have the mains and output transformers upgraded, probably with Sowters, the ultralinear/triode switch taken out of the signal path and upgrade the speaker terminals to WBTs or something of that ilk.
I have decided to leave ripping out the preamp control circuitry and point-to-point wiring of internal components until after I have assessed the benefits of the transformer upgrades. Basically, it will be more fun that way and I will also be in a position then to advise others if necessary on the effects of each modification should they be interested in going down the same route with their equipment.
So, Anthony, start getting your tools sharpened and your soldering iron prepared for action :smoking:
Marco.
anthonyTD
19-06-2008, 20:19
The Yaqin will be ready for modifying further in a few weeks. The plan is to have the mains and output transformers upgraded, probably with Sowters, the ultralinear/triode switch taken out of the signal path and upgrade the speaker terminals to WBTs or something of that ilk.
I have decided to leave ripping out the preamp control circuitry and point-to-point wiring of internal components until after I have assessed the benefits of the transformer upgrades. Basically, it will be more fun that way and I will also be in a position then to advise others if necessary on the effects of each modification should they be interested in going down the same route with their equipment.
So, Anthony, start getting your tools sharpened and your soldering iron prepared for action :smoking:
Marco.
hi marco,
no worries, although i would still recomend you have all the controls and redundant wiring removed, just to simplify the signal path, but its your call.
anthony.:)
Yes we can go for that also if it's not too much trouble :smoking:
We'll leave the fascia change though until the internal point-to-point wiring is done.
I can't believe how good the Yaqin sounds at the moment, particularly since the Croft has been modified, so it will be very interesting indeed to hear just how good it can get...
I believe there is lots of untapped potential. What do you think?
Incidentally, does anyone know where you can buy those 'propeller-wing' speaker binding posts used in the likes of Mark Levinson power amps?
I would like to have those fitted to the Yaqin as I use spade connectors on my speaker cable and like the way the 'propeller-wings' clamp nice and tightly to the speaker terminals, which I'm sure makes for an excellent connection.
Marco.
Hope it goes well..... Then I'll bring over the WD88 to duff it up. Ha! :eyebrows:
Incidentally, does anyone know where you can buy those 'propeller-wing' speaker binding posts used in the likes of Mark Levinson power amps?
No, but I've seen a ebay geezer selling Cardas pure copper terminals. They have a Hex nut turny bit that you can crank up with a spanner! :fingers:
Have you got a link, Mike?
You're welcome to bring the WD88 along anytime :)
I heard the EL84 (is it?) version recently and was very impressed.
Marco.
KEL84 is the baby in the range, the '88' is similar but, well.... like a bionic 84, bigger, stronger, faster.... :lolsign:
I'll have a mooch about for that ebay bloke and give you the details when I find him. Think he's in the US.
Can't find that fella in the US, but here's some:
http://cgi.ebay.co.uk/Cardas-Original-CCBPS-copper-speaker-banana-terminal_W0QQitemZ180253594904QQihZ008QQcategoryZ5 0593QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
Nice one, dude. They look pretty good. I'd still love to find out though where I can get hold of those 'propeller-wing' ones I referred to earlier... :scratch:
I guess Mark Levinson would know the supplier.
Or perhaps Anthony or Nick would know?
Marco.
I think Mark Levinson (the man) had his company (the name) more or less 'robbed' from him (allegedly)!.... I seem to remember reading something about it ages ago. :scratch:
Here's an idea for you Marco:
Once our respective modifications are completed (I've got more or less the same plans for my '88' as you have for your bag of... er Yaqin) we'll arrange a head-to-head. Just for the hell of it.
:gig:
Sound like a plan? :)
Defo! Your place or mine? Just be prepared to weep into your soup when you lose shweety, and lose royally :lolsign:
:lol:
:ner:
Marco.
Both.... s'only fair! ;)
I can see a 'wager' on the cards here! :eyebrows:
Maybe we need an independent adjudicator. Where's JC when when we need him eh? :eyebrows: :eyebrows:
:lolsign:
Hehe...
We should definitely do this in the summer. When I come up to yours you can take me for lunch at that nice country pub you posted a link to a while back. I shall of course return the compliment at our local McDonalds :eyebrows:
Marco.
Ooer!...
This is starting to sound like some sort of date! I hope yer no a big girly party frock?......
Old Peculier (http://www.theakstons.co.uk/ales/view_detail.php?id=9) is a mans drink ya know, we can't go to The Lion and drink shandy. Oh no!:lolsign:
Big girl party frock?
Aye, can you not see ma big hairy arse peeking thru my chiffon tutu? :lol: :lol: :lol:
Marco.
Well... now that you mention it!
I thought it was just your incontinence pants though... :D
Right, enough of this hilarity!
Back on topic... Check this out:
http://cgi.ebay.co.uk/NEW-KT88-tubes-amp-YAQIN-MC110B-60W-better-than-MC100B_W0QQitemZ330244496007QQihZ014QQcategoryZ328 0QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
Less bling and even better! But mine will be even better-er still when I've finished with it :eyebrows:
Dual mono roolz, Mikey. That's why your WD88 is gonna come a piss poor second best :ner:
Tee hee...
Marco.
Pah!... It's a heated bread bin. :lol:
Heated?
Aye, it'll roast your WD88 nae bother! :lolsign:
Marco.
http://i5.photobucket.com/albums/y198/davhar/51XTYCY15AL_SS500_.jpg
http://i5.photobucket.com/albums/y198/davhar/87db_1.jpg
:confused:
Heated?
Aye, it'll roast your WD88 nae bother! :lolsign:
Marco.
Yeah, whatever........ :upyours:
http://i5.photobucket.com/albums/y198/davhar/51XTYCY15AL_SS500_.jpg
http://i5.photobucket.com/albums/y198/davhar/87db_1.jpg
:confused:
:D: :D: :door:
Marco.
Just found this, supposed to be the schematic for the Yaqin MC100B
http://i273.photobucket.com/albums/jj220/kingbusoms/Yaqin_mc_100.jpg
This looks very, very nice! Triode or ultralinear output configuration. Only two capacitors in the signal path. A pity though the designer(s) didn't look up their history books. The third type is a common anode follower, a circuit far from linear. With the same amount of tubes it could have been a "White" follower! And if they had known Hiraga's works it would have been possible to have 1 tube completely out of it.
But, all in all, it looks better then some of the circuits from across the ocean.
John
This looks very, very nice!
Nice of you to say so, John, and your comments are noted :)
The Yaqin certainly sounds very good, particularly with the dual-mono construction, which I'm sure is influential in the sound it produces. I always feel having a mains transformer for each channel significantly improves things, and to that end have always preferred monoblock to stereo amps, all else being equal. Changing the stock Chinese valves for something better and making it safe for UK voltage is all it needs to make it quite a special sounding amplifier.
Marco.
Defo! Your place or mine? Just be prepared to weep into your soup when you lose shweety, and lose royally :lolsign:
:lol:
:ner:
Marco.
Ooh, that's fighting talk now!!!
The WD88 is sounding better than ever with it's new KT's in place.
I wouldn't be to cocky if I were you! HeHe. ;)
Nice one, Mikey. So are finding the cryos superior to the standard Svets?
I found that the difference was less than subtle! :eyebrows:
Marco.
Steve Toy
02-07-2008, 11:02
Enough of this idle banter. It's time to bring the AOS classic series amp to the party with the above mentioned Cryo treated Svets, valve rectification (that the Yaqin doesn't have :ner:) in the form of two Mullard GZ 34s and a set of four Philips JAN 6SN7 driver valves. Unlike the Yaqin this is also a pure class A circuit.
Sweet as a nut :violin: with grunt :rock: to boot, what more could you want? :eyebrows:
Hmmm...:scratch: valve rectificaton could give you an advantage there Steve. I rather think the quality of the transformers will be more important though.
The WD uses SS like the Yaqin, might be an interesting party! :smoking:
LOL @ Steve's above post!!
I don't know, would valve rectification necessarily be an advantage? I guess it depends on the circuit.
What I can say is that the valve rectification was removed in my Croft pre (replaced with a MOSFET) which has had the effect of lowering impedance resulting in improved sound quality. Of course the whole new (massive) PSU, new Jensen caps, Alps Black Beauty pot, etc, may also have something to do with it ;)
However I think a TD/AOS, WD88, Yaqin, shoot-out is a fun idea. Bring it on! :smoking:
Marco.
What I can say is that the valve rectification was removed in my Croft pre (replaced with a MOSFET) which has had the effect of lowering impedance resulting in improved sound quality. Of course the whole new (massive) PSU, new Jensen caps, Alps Black Beauty pot, etc, may also have something to do with it
Just FYI, if the changes to the Croft power supply were the same as Ians, then it was the 6080 regulator that was replaced with a MOSFET not the rectifier, it think that always was SS.
Alps Black Beauty pot,
Hmm!... I'm using the same pot Marco. It replaced an Alps Blue, but to be honest the difference was pretty small, the shunt mod made a MUCH bigger improvement. I might be ripping it all out soon though and using a proper Pre-amp, as it stands it's really just a power amp with a passive pot built in. And some input switching of course.
Shoreee, my mistook. I was getting mixed up between regulation and rectification... :doh:
What's good about valve rectification then, Nick? :)
Marco.
What's good about valve rectification then, Nick?
Slow start
Lack of switching noise due to there being no reverse current period.
In the realm of different, neither good or bad, valve rectifiers are higher impedance, and can't handle the same spikes as SS, so power supplies tend to use less capacitance, and often also use chokes for smoothing (though SS can and does do the same thing, the possibility of using big caps normally is too attractive to designers)
Ahhh... good old pro's and con's. I wonder if there really IS such a thing as a perfect power supply? Doubt it! :confused:
I like supplies with chokes, dunno why really, they just seem to give a nice clean and smooth sound. The WD88 uses one, as does the psu for the phono stage that I'm (slowly) building, designed by Lurcher I might add! :)
If there was a perfect supply, it would only be for that one amp.
Chokes are generally good things, IMHO. Especially as anode loads, but thats a different story.
Especially as anode loads, but thats a different story.
I'm sitting comfortably! :)
A "PI-filter" gives a better isolation from disturbances at the mains. And a C-L-C filter even performs better (then C-R-C). What you'll get is a quieter amp. And probably more detail from small signals.
Tube rectifiers are loved by some, but it gives quite a loss so the transformer has to be winded secundary for some 50 Volts higher then SS.
The advantage of SS is the low loss and the capability of bigger currents (in peaks!). Regulation also helps in isolating from the mains. It's a pity that regulators for high voltages are hard to find. So one has to construct it discrete (and take care for short circuit appearances). A better way imho is the use of a shunt regulator. That could be a power fet or a power tube. Both work fine (at the cost of some extra current).
Anyway, regulators are not to be used in the output circuitry of a power amp. But in the pre-stages it works fine.
BTW why not use a different phase shifter?
John
Anyway, regulators are not to be used in the output circuitry of a power amp. But in the pre-stages it works fine.
Well, we might have to agree to differ there :-)
Hmm!... I'm using the same pot Marco. It replaced an Alps Blue, but to be honest the difference was pretty small, the shunt mod made a MUCH bigger improvement.
You might be right, Mike. I have no way of comparing the black to the blue Alps in terms of out-and-out sound quality. However the black has a nicer, more positive, feel in use and appears to give more accurate stereo, particularly at lower listening levels.
The frankly massive difference in performance I'm getting now with the Croft is no doubt more down to the other mods I've had done. I really must get round to writing something about the modifications Glenn has carried out. I think that side of his new business has got as much potential as his new range of electronics, which hopefully I should get a listen to soon.
I might be ripping it all out soon though and using a proper Pre-amp, as it stands it's really just a power amp with a passive pot built in. And some input switching of course.
If you do that'll be interesting. I've yet to hear a passive pot (or preamp) outperforming a top-notch active design, particularly a valve-based one. I'll be listening Mo's modified Glasshouse passive device soon, which Steve has borrowed, and comparing it to the Croft so that should be interesting :)
Marco.
Steve Toy
03-07-2008, 19:08
Not so soon Marco. A buyer has come forward. It is now on its way to Lancashire.
A buyer for what, mate? The Spectral or the Glasshouse? I didn't realise that either were for sale :scratch:
Marco.
I think a TD/AOS, WD88, Yaqin, shoot-out is a fun idea. Bring it on! :smoking:
Marco.
Date?..... C'mon, lets get this sorted! ;)
Well if Shtevie boy is gonna be involved you'll need his diary, too...
My crystal ball sees you coming down to Wales where Shtevie baby will meet you and bring his AOS/TD, but it'll need to wait until I've finished fettling the Yaqin (imminent) :)
Or you could always come to the Chester fest?
Btw, what difference did you hear with the cryo'd Svets?
Marco.
Btw, what difference did you hear with the cryo'd Svets?
Marco.
Not tellin! :ner:
Yet...
Haha, what are you like! If you can't hear the difference you're f*cking deaf! :lolsign:
Marco.
Eh?... what?... did someone say something?
At least you've got a proper matched quad this time regardless ;)
Marco.
I have several matched quads!
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