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View Full Version : The Tube Distinctions AOS classic series valve amp - the verdict



Steve Toy
23-06-2008, 15:33
It was a gamble as I was buying an amp with the intention of having it modified from the outset without knowing exactly how it was going to turn out. I'm not really into leaps of faith but having heard the Chinese Yaqin amp in my own system with which I was extremely impressed, I thought I had to have something at least similar.

The problem with the Yaqin was that it needed a step-down transformer to work safely with UK voltages and I didn't fancy this option. As good as the Yaqin sounded, the mains transformers are wound for 220 volt not the 240 for the UK where voltages have been known to push towards the 250 mark. Hook up a Yaqin or some other Chinese import here and you may get the fireworks to accompany your music before the music stops. This has already happened to at least one person...

Our resident electronics engineer and valve specialist Anthony even advised not to even switch such an amp on until someone like himself had had a good look at it and made sure it was safe. Thus from a purely safety angle my only option if I wanted a Chinese-built valve amp was to go for one with mains transformers specified for the UK. Two options sprang to mind: something from Prima Luna or the Puresound amps imported and made safe by Guy Sergeant based on but quite different to the Bewitch available for about the same money as the Yaqin. Ok, for the luxury of made-for-UK reassurance I was paying £1100 instead of under £400. Some of the price difference obviously included distributor and dealer mark-ups but I think this was definitely one instance where such middle men were adding value to my purchase, not just from the safety aspect but also the fact that buying from a dealer enables you to hear the product before you buy it.

I bought mine from Tony of Coherent Systems who agreed to bring a Puresound A30 to my house to hear in my own listening environment with my speakers, a pair of slim and elegant yet puncy Piega TS5s. I was satisfied that the A30 in stock form was able to drive them easily and so it stayed put when he left, replacing a Densen B330 solid state amplifier costing £3000. The valve amp costing just over a third of the price was already proving to be more involving and enjoyable to listen to in the context of my own system. Good as the Densen amp is, it does a far better job in an all-Densen system than in my mongrel set-up.

The Puresound didn't exert the same vice-like grip over the bass of the Piegas as the Densen but this proved to be an actual improvement to my ears in that bass sounded more natural, tuneful and rhythmic; low notes were now given the chance to tell their full story and not just how their lives had abruptly begun. Music with any kind of rhythm took on more of a bouncy quality that didn't just make you tap your feet but actually want to get up and dance. The midrange was also clearer, more natural and overall coherence was much improved. My wife Tasha was also beginning to actually sit down and listen to music for the first time in her life rather than just have it playing in the background while she was either in her car driving or at home doing the ironing.

If there was a downside it was that the upper frequencies, whilst more extended now, did have a slightly glassy quality and the amp seemed to need to be turned up a bit before it had any real drive. It wasn't really the last word in transparency or dynamics either but for its price you could more than forgive these relatively minor shortcomings. I'd say it certainly wiped the floor quite convincingly with just about every other commercial amplifier up to and above the £1000 mark. It was fun, involving and enjoyable and had great timing acuity even if it didn't quite yet have that tingle factor to make the hairs on your arms and neck stand up. It could certainly play music and put a big smile on your face though.

I enjoyed this amp in stock form for the month of April this year until I took it to Anthony's in South Wales where it was to undergo extensive modification as planned from the outset. Whatever was to happen from this point on, I'd had plenty of time to get to know the original, unmodified Puresound A30 and would therefore be in a much better position to appreciate the changes Anthony was going to bring to it.

During the month that the amp was at Anthony's I had on loan his baby Copper amp to keep me going. It was more transparent and dynamic than the Puresound A30 but then it should be considering its complete set of NOS valves including GEC KT88s, quality bespoke transformers, a copper chassis eliminating eddy currents and point-to-point wiring throughout in place of PCBs. It was perhaps a little forward and slightly brittle sounding at times but I'd like to attribute that to an impedance mismatch; the output transformers are wound to see a 6.8 ohm load and the Piagas are a nominal 4 ohm.

On the whole, if the Puresound post-modification was to be nearly as good as this Copper amp it would certainly have been worthwhile. The modifications included changing all the valves from Electro Harmonix 6550s to Svetlana Cryo-treated KT88s, the Chinese driver valves were replaced with Philips JAN 6SN7s and the Chinese rectifier valves were replaced with NOS Mullard GZ34s. The volume circuitry was removed along with input selection and signal paths were shortened. The circuit was also was altered to optimise the output transformers more with the aim of improving dynamics and resolution. Finally the Triode/Ultra Linear switches were removed from the circuit path with the amp set permanently to UL mode.

Cosmetically a black acrylic sheet replaced the front panel that used to house the now-redundant volume and input selector knobs. In all the mods cost a shade under £700 including valves, parts and labour.

The amp returned home as the Tube Distinctions AOS classic series (to commemorate the Art of Sound Forum) and I was eager to hear if my gamble had paid off. First impressions suggested more drive, articulation and texture in the bass than even the Copper amp, never mind when it was the unmodified Puresound A30. Dynamics and detail seemed better across the board and the amp seemed to have guts even at lower volumes whilst sounding more at ease and less strained at higher volume levels.

However, within a few days I noticed that the amp was sounding rather fatiguing. There was a relentless shrillness to upper frequencies that were beginning to set my teeth on edge. I was assured that this was part of burn-in but what if it was never going to go away? Meanwhile how am I going to burn in my new amp if it sounded so unpleasant? This shrillness wasn't noticeable initially but now I knew it was there it wasn't something I could tolerate for any length of time. I found myself wincing instead of tapping my feet.

Perhaps a spot of tube rolling would ease the pain and make it more pleasant to listen to so Anthony agreed to send me a pair of Mullard GZ32s to put in place of the GZ34s as they have a somewhat 'darker' tonal characteristic. It was also suggested that the Philips JAN 6SN7s had a rather forward sounding treble and these may well be the culprits, so a set of Electro Harmonix 6SN7s were sent for me to try. Before these valve alternatives had even arrived the shrillness was already beginning to fade, albeit slowly so I felt encouraged that I hadn't made a big mistake.

I did wonder how these tonal changes, both with different valves and with burn in were possible given that the amp measured ruler-flat from 4 to 100,000 Hz. Perhaps they are something some of us just imagine... Perhaps there is more to tonality than frequency curves. Pehaps it has more to do with distortion characteristics at given frequencies than with output....

Anyway, I tried the GZ32s and they seemed just to sound duller in comparison so the GZ34s were promptly put back in. I used two Céline Dion tracks, That's the way it is and The first time ever I saw your face to make my comparisons because the music is familiar, the recording quality is good and I would more easily get a second opinion from Tasha who is a big Céline fan. This was to be her first A/B/X dem swapping the Philips JAN 6SN7s for the Electro Harmonix versions.

On some of the higher notes/louder passages that Céline sings there was a degree of harshness that Tasha commented on. With the EHs this effect was lessened somewhat and her voice sounded more pleasant. Tasha noted this change with ease. I then swapped the JANs back in and asked her what she thought overall. My own views were that the EHs had got rid of the harshness by killing the dynamics and the tune. The first time ever I saw your face is a ballad that sets your hairs on your arms standing on end, especially when the violins join in at the point when she sings at full tilt. It just wasn't happening with the EHs. It just sounded easy to listen to, dull and lifeless all at the same time. I'd made my mind up. Interestingly, Tasha agreed with me. I always believed that she just followed the vocals but she said that she was listening to the whole music and it was more enjoyable overall with the JANs in place.

Over the next few days the harshness further faded and the amp completed the transition from initially impressive/ultimately fatiguing to acceptable and then onto wow, this sounds absolutely gorgeous! The higher frequencies were taking on an extra level of refinement bringing better tunefulness, harmonics, decay and a bigger soundstage to the party. This amp was now exceptional. It had cost me just under £1800 in total but could well see off many a commercial amp up to the 5k mark. Many thanks to both Guy Sergeant and to Anthony for allowing this experiment to be undertaken. It has easily surpassed my expectations to become probably the best sounding amplifier I've heard.

And it's mine! :)

Marco
23-06-2008, 16:20
Good stuff so far, Steve :)

I'm particularly interested to hear how you would define the effect of Anthony's modifications and in what way the performance of your amp now differs from the original A30.

Your observations so far mirror my own regarding the Yaqin and ECS amps - we've both given up expensive and highly regarded solid-state designs for much less expensive Chinese valve ones, albeit yours is now more Welsh than Chinese, and mine will soon be sharing similar DNA ;)

It's a complete departure from the 'flat earth' world we used to inhabit and enjoy, but things have moved on and valves are now every bit as funky as the Naim and Densen gear we once cherished whilst a welcome daub of colour has been added to the previously more monochromatic solid-state sonic landscape.

Trust me you won't be able to go back, as I've already alluded to in another thread. FEPs are now as about desirable as a dose of crabs :lol:

Anyway, enjoy and let's hear about the second part of your journey soon!

Marco.

Mike
23-06-2008, 17:51
C'mon ya slacker... more!

;)

Marco
23-06-2008, 18:24
I wonder if the rest will arrive before my 1210 review? :eyebrows:

Marco.

Togil
23-06-2008, 18:51
Well I think Steve has altered his original post to include his conclusion, quite confusing to a future reader of the thread.

Mike
23-06-2008, 18:58
I wonder if the rest will arrive before my 1210 review? :eyebrows:

Marco.

I think you can pretty much count on it bud! :wanker: :lolsign:

Marco
23-06-2008, 19:04
Hans,

Yes he has a bad habit of doing that! :doh:

What are you doing ya numpty? Wait until you've written the whole thing and then post it! :lolsign:

Or if you're going to do it in two stages create two separate posts...

Maybe he's trying to be 'artistic' ;)

Marco.

pure sound
23-06-2008, 19:32
If I'd known it was going to be used for Celine Dion I'd never have gone along with this. I'm sure Anthony wouldn't either :lol:






Nice write up Steve

Iain Sinclair
23-06-2008, 20:20
Hmmm. To me, the write-up highlights some of the problems with 'subjective' reviewing*, as well as throwing a glaring spotlight on Steve's musical taste. And I was positively shocked by the statement that 'My wife Tasha was also beginning to actually sit down and listen to music for the first time in her life'!

*Most obviously, in the statement on the lines of 'this sounded harsh, but now it's burned-in it sounds wonderful'. Or maybe Steve's ears have just made the necessary allowances for the perceived harshness?

Togil
23-06-2008, 20:49
I cannot help but feeling that an amp which depends so much on which brand of valve is used is badly designed. :scratch:

anthonyTD
23-06-2008, 21:18
I cannot help but feeling that an amp which depends so much on which brand of valve is used is badly designed. :scratch:
a valve must be classed as a circuit in its own right,with its own capacitance and reactance values,to name a few of its characteristic traits, hence the reason they all sound different, but there are recognised types that definitely sound more "right" than most others, these are invariably old stock versions, coming from an era when valves were pretty much all there was, so, it would seem logical to some that they were made more "right" than most modern equivalents!
anthony...:)

anthonyTD
23-06-2008, 21:25
If I'd known it was going to be used for Celine Dion I'd never have gone along with this. I'm sure Anthony wouldn't either :lol:






Nice write up Steve

my heart will go on, and on, and on....:):eyebrows:

Marco
23-06-2008, 21:39
Iain,


Hmmm. To me, the write-up highlights some of the problems with 'subjective' reviewing*, as well as throwing a glaring spotlight on Steve's musical taste.


I don't know what Steve was doing digging out Celine Dion albums to highlight the amp's musical prowess but trust me that's not all he listens to :oops:

In retrospect perhaps he'd have been better digging out some Keb Mo, Stacey Kent, Mary Chapin Carpenter, Tiesto, Newton Faulkner and tons of other stuff that I know he's got in his collection.


And I was positively shocked by the statement that 'My wife Tasha was also beginning to actually sit down and listen to music for the first time in her life'!


LOL. I realise that's how it reads but he didn't mean it that way. Tasha loves music but she, like many women in my experience, prefers to listen to music whilst doing something else rather than just sitting there in front of the hi-fi. The fact that the TD/AOS amp (and copper amp) was so good made her for the first time want to sit down and listen.

My wife's the same - now and again she'll sit for an hour or so and listen to music with me but after that she gets bored and will go off and watch TV or something, whereas when I have mates round we'll sit for hours on end listening to music. However she'll quite happily go to concerts/gigs with me and sit or stand listening to bands/orchestras for as long as is necessary and loves every minute of it.


*Most obviously, in the statement on the lines of 'this sounded harsh, but now it's burned-in it sounds wonderful'. Or maybe Steve's ears have just made the necessary allowances for the perceived harshness?

Hi-fi equipment in my experience does take a while to burn-in and perform optimally from new and his TD/AOS amp, which has recently had a lot of new components added, is no different. This is hardly a new phenomenon. I also know exactly what happened regarding the harshness Steve mentioned and it was simply a case of getting new valves (and the amp) to burn-in and perform as designed.

Marco.

Steve Toy
23-06-2008, 23:51
I cannot help but feeling that an amp which depends so much on which brand of valve is used is badly designed.


I cannot help but be encouraged by the more transparent designs that show up the differences.

The amp works regardless of the valves used but getting it to sound just right does require the right choice of valves. If my amp after burning in rejected the better, more vibrant valves in place of the duller ones I'd be worried.

I guess your choice of amp would be sufficiently opaque so as not to make a difference.

Steve Toy
24-06-2008, 00:19
Or maybe Steve's ears have just made the necessary allowances for the perceived harshness?

No allowances could be made given that the harshness wasn't apparent straight away.

Such glib comments overlook the fact that we dont listen to music constantly. We turn it off and on and come back repeatedly over time.

You never get used to harshness, quite the opposite in fact.

Togil
24-06-2008, 07:30
I guess your choice of amp would be sufficiently opaque so as not to make a difference.

No, but it should be optimally designed for the stock valve , I once got a very curt reply from EAR when I asked whether there were any "better" KT90s for their designs

However I do realise this may not be possible at the given price point.

Marco
24-06-2008, 08:00
I once got a very curt reply from EAR when I asked whether there were any "better" KT90s for their designs


Haha, I can relate to that! That'll be the famous/infamous (delete as you feel applicable) Mr Tim de Paravicini :lol:

He's actually different face-to-face. I was at his factory recently with a friend to have his 509s serviced and he is a charming, though somewhat eccentric, chap. Interesting set-up at the factory, too. He has a great rapport with his staff. I learned quite a few things.

Hans, Steve's amp *was* optimally designed for the stock valve - that's the point, and why the Electro-harmonix valves Steve tried didn't work. The amp (and the stock valves) just needed to burn-in to lose the initial slightly forward presentation. All is now well.

Marco.

Steve Toy
24-06-2008, 10:55
Hans, Steve's amp *was* optimally designed for the stock valve - that's the point, and why the Electro-harmonix valves Steve tried didn't work. The amp (and the stock valves) just needed to burn-in to lose the initial slightly forward presentation. All is now well.



Indeed the amp was designed (having been modified) to work with the Svetlana KT88s, Mullard GZ34s and Philips JAN 6SN7s fitted. The alternative EH 6SN7s and Mullard GZ 32s didn't work as well.



LOL. I realise that's how it reads but he didn't mean it that way. Tasha loves music but she, like many women in my experience, prefers to listen to music whilst doing something else rather than just sitting there in front of the hi-fi. The fact that the TD/AOS amp (and copper amp) was so good made her for the first time want to sit down and listen.



Well put Marco. The process of her beginning to listen more actively to music in the home began with the unmodified Puresound A30 which she described in her own words as being "involving" in its portrayal of music. I guess the involvement factor is the key to getting people to actually sit down to listen rather than just have the music "on" while attending to other things like housework or reading a magazine.

Tasha is a music lover but until recently the recorded music in the home experience was never like attending a concert, probably still isn't (she goes to two or three a year including V Festival) but I think we are close enough now for her to just do the sitting, listening and enjoying.

Steve Toy
24-06-2008, 11:18
So if you want good quality valve amplification without spending 5k here are your options in summary:

1) Buy a direct-import Chinese amp like the Yaqin or Bewitch for under £400. Use a step-down transformer for safety or your music may be smokin' (this has actually happened btw as Richard is conveniently overlooking so be warned!) Get used to it first before sending it to Anthony of Tube Distinctions or someone else doing a similar job. You can then fully appreciate the improvements when your amp comes back. You will need to pay for new mains transformer(s) that work with UK voltages which may well cost you as much again as the other mods and valves.

2) Buy the above and don't even switch it on. Instead send direct it to Anthony for modification. You'll need to replace the mains transformers as above. The amp will be great when it comes back but you won't know how it sounded to begin with.

3) Buy an amp that has been adapted for use in the UK and is certified. You'll pay more for it but the price difference will be about the same or less than replacing mains transformers. You'll get the chance to audition it before you buy it and appreciate the improvements when it comes back from being modified.

There, I've outlined my experiences and reasoning wrt this amp. What anyone else may decide to do if it is of interest to them is of their own choosing. Hopefully their choices are now informed ones.

Isn't this what forums like this are supposed to be about?

Iain Sinclair
24-06-2008, 17:33
And/or

4) Buy a good second-hand amplifier at a fraction of the 'new' price.

Iain Sinclair
24-06-2008, 17:51
Well put Marco. The process of her beginning to listen more actively to music in the home began with the unmodified Puresound A30 which she described in her own words as being "involving" in its portrayal of music. I guess the involvement factor is the key to getting people to actually sit down to listen rather than just have the music "on" while attending to other things like housework or reading a magazine.

Tasha is a music lover but until recently the recorded music in the home experience was never like attending a concert, probably still isn't (she goes to two or three a year including V Festival) but I think we are close enough now for her to just do the sitting, listening and enjoying.

Fair play. I was shocked because my wife has for as long as I've known her, sat and listened to music, even played on a cruddy Dansette portable record player. She's not fussed about hifi, possibly because she has a very good 'ear' for music so doesn't need a high resolution system to enable to enjoy recorded music.

Marco
24-06-2008, 18:53
Yep we're all different, Iain.

It's good that your wife likes to sit with you and listen to music. Personally, I don't think couples spend enough time together these days, and in some cases in today's busy world, almost live separate lives. Consider yourself lucky because most women I know wouldn't have the time or patience to do what your wife does.

One can only speak from experience, but I've found that in general most women like (perhaps need?) to multi-task, as Steve mentioned, doing housework or reading, etc, whilst listening to music - few have the luxury of spare time in between working, housework, looking after kids, etc to sit and listen to music for extended periods, however it might be 'on' whilst they're busy about their daily business. I'm not saying they're all like that, but I think quite a few are.

Men are different - we're lazy b*stards (in comparison)!

As far as my wife is concerned she's the type who always needs to be doing something and 'on the go'. There's no way, despite how much she enjoyed the music or how good it sounded, she could just sit there listen - perhaps half an hour or an hour, tops, then she'd be bored and offski :lol:

It's the same when we're on holiday. I can spend hours just reading a book chilling out in the sun enjoying a few beers or a bottle of wine somewhere, whereas she's off sight seeing, visiting museums, looking at shops, or whatever. However there are also plenty of times when we do things together. It's important to strike the right balance - we all need a bit of space and 'me' time.

Bloody hell, how did I go off on this tangent? :lolsign:

Marco.

Togil
25-06-2008, 10:13
a valve must be classed as a circuit in its own right,with its own capacitance and reactance values,to name a few of its characteristic traits, hence the reason they all sound different, but there are recognised types that definitely sound more "right" than most others, these are invariably old stock versions, coming from an era when valves were pretty much all there was, so, it would seem logical to some that they were made more "right" than most modern equivalents!
anthony...:)

Anthony,

do you already have any ideas how to improve the new Quad II Eighty monoblocks ?

anthonyTD
25-06-2008, 10:50
Anthony,

do you already have any ideas how to improve the new Quad II Eighty monoblocks ?
yes, start again!
but seriously, i was never a fan of the original quad 2 circuit, its probably [in my opinion] responsible to a large degree for the miss conception of what valve amplifiers are suposed to sound like, ie, soft, warm, with limited frequency response and power, etc, but as stated, thats my opinion, and i understand and respect that there are a lot of people around the globe who use them, and apreciate their sonic qualities, i am just not one of them...
anthony...:)

Mike
25-06-2008, 11:05
I'm not so sure the 'new' ones have much in common with the 'old' ones.

tfarney
25-06-2008, 12:34
yes, start again!
but seriously, i was never a fan of the original quad 2 circuit, its probably [in my opinion] responsible to a large degree for the miss conception of what valve amplifiers are suposed to sound like, ie, soft, warm, with limited frequency response and power, etc, but as stated, thats my opinion, and i understand and respect that there are a lot of people around the globe who use them, and apreciate their sonic qualities, i am just not one of them...
anthony...:)

So when a valve amp doesn't sound warm, soft and, as we say here to the left of the pond, "tubey," what are the characteristics that set it apart from a good solid state amp?

And while we're on the subject, what are some of the common (as in readily available, still in production) valves that can make really good hifi? I've seen a couple of small SET/SEP amps advertised lately that use EL84s and 6v6s, which appeal because there are so many popular guitar amps that use those, so it seems that on-going production is a safe bet. But I have no idea how they perform in a hifi context.

Tim

Peter Stockwell
25-06-2008, 12:35
Personally, I don't think couples spend enough time together these days, and in some cases in today's busy world, almost live separate lives.

This must be a thread for the padded cell (ooops! Wrong Forum :doh: ) ;)

Seriously, Mrs L, that's the missus, does like music and does listen, but not as singlemidedly as me. She certainly has the ears to tell when the rig is "On" or "Off". Once the SL1210 was turning she heard that it was better than the Garrard.

We're lucky to enjoy many activities together, such as concerts, golf, music, sport etc.

anthonyTD
25-06-2008, 13:07
So when a valve amp doesn't sound warm, soft and, as we say here to the left of the pond, "tubey," what are the characteristics that set it apart from a good solid state amp?

And while we're on the subject, what are some of the common (as in readily available, still in production) valves that can make really good hifi? I've seen a couple of small SET/SEP amps advertised lately that use EL84s and 6v6s, which appeal because there are so many popular guitar amps that use those, so it seems that on-going production is a safe bet. But I have no idea how they perform in a hifi context.

Tim
hi tim,
some of the current production valves are very good, especially the original svetlana's, in fact russian valves on the whole are quite good, with the exception of some of the ones branded up as something their not, [you know who you are] JJ valves are also very good, but my point was, in my opinion, none seem to have the magic that some of the most popular brands of the by gone era have.
anthony...:)

Togil
25-06-2008, 13:18
This must be a thread for the padded cell (ooops! Wrong Forum :doh: ) ;)

Seriously, Mrs L, that's the missus, does like music and does listen, but not as singlemidedly as me. She certainly has the ears to tell when the rig is "On" or "Off". Once the SL1210 was turning she heard that it was better than the Garrard.

We're lucky to enjoy many activities together, such as concerts, golf, music, sport etc.

Well back in the 60s my mother was the first one in the family to complain about all this "rumbling" so out went the Braun turntable ( don't laugh, they made some excellent HiFi ! ) and in came the Thorens...

NRG
25-06-2008, 14:42
So when a valve amp doesn't sound warm, soft and, as we say here to the left of the pond, "tubey," what are the characteristics that set it apart from a good solid state amp?

Tim

Tim, I would categorize a good modern valve amp as having a very liquid open midrange with great detail and insight. It will also have a good top end without any edge or grain to the treble or to the overall presentation (as long as 3rd harmonic distortion is kept low).

It should not sound warm but clean, open and smooth, the bass should be tighter than older designs (lower bloat) due to better TX winding techniques and materials. Bass won't approach SS impact levels though.

Marco
25-06-2008, 14:48
I'm with you on 95% of that, Neal, apart from this bit:


Bass won't approach SS impact levels though.


I guess it depends on the solid-state and valve amp in question, particularly whether the valve amp is push-pull, S.E.T, and which output valves it uses. All I can say from experience is that my KT88 60W P/P Yaqin has every bit as much bass impact (in fact probably more) than my ECS 200W monoblocks, and they weren't exactly lacking in that department before :)

Marco.

tfarney
25-06-2008, 14:49
hi tim,
some of the current production valves are very good, especially the original svetlana's, in fact russian valves on the whole are quite good, with the exception of some of the ones branded up as something their not, [you know who you are] JJ valves are also very good, but my point was, in my opinion, none seem to have the magic that some of the most popular brands of the by gone era have.
anthony...:)

Oh, I'm an old guitar player and I completely get the NOS thing. What I'm trying to figure out is if there are types of valves that are better for hifi than others, and specifically, if any of the valves that are common in guitar amps and, therefore, have a large market assuring on-going production, are good hifi valves in the right amp design. Those common guitar amp valves would be EL34, EL84, 6v6, 6L6, KT88.... In particular, I've seen quite a few low-powered (what I need) valve amps on the net built around EL84s and 6v6s. These are great tubes for low-power guitar amps, but the requirements are quite different (avoiding clipping vs generating it).

I once had a pair of NOS Visseaux 6v6 GTs from 1951 in my '65 Deluxe Reverb. Many would have considered them a bit clean for that application, but they delivered this wonderful warm, glimmering clean tone, and when you did push them into clipping they took on a texture that was a perfect balance of cream and grit. Ah, those were the days...

Tim

anthonyTD
25-06-2008, 17:07
Oh, I'm an old guitar player and I completely get the NOS thing. What I'm trying to figure out is if there are types of valves that are better for hifi than others, and specifically, if any of the valves that are common in guitar amps and, therefore, have a large market assuring on-going production, are good hifi valves in the right amp design. Those common guitar amp valves would be EL34, EL84, 6v6, 6L6, KT88.... In particular, I've seen quite a few low-powered (what I need) valve amps on the net built around EL84s and 6v6s. These are great tubes for low-power guitar amps, but the requirements are quite different (avoiding clipping vs generating it).

I once had a pair of NOS Visseaux 6v6 GTs from 1951 in my '65 Deluxe Reverb. Many would have considered them a bit clean for that application, but they delivered this wonderful warm, glimmering clean tone, and when you did push them into clipping they took on a texture that was a perfect balance of cream and grit. Ah, those were the days...

Tim

hi tim,
ok, out of the ones you mention for low power, [ie, run conservitably three and half watts single ended, and up to 12 watts push-pull] i would rate the sound of the 6v6 over the EL84 just my prefrence, but both are good little valves, although they are the same power equivilent,the 6v6 is a tetrode, and the el84 is a pentode, tetrodes tend to produce a little less of certain types of distortion, and as you say, the 6v6 can be found in some great sounding little guitar amps...
the 6l6 and el37 are again around the same power out, but like the 6V6, the KT66, and the KT88, it is a tetrode, where as the EL84, EL34, EL37, etc are all pentodes.
hope this helps.
anthony:)

Mr. C
13-07-2008, 16:11
Steve kindly brought this amp round for demo last week, Tony (M) has done a fine job in upgrading this amplifier, giving it a nice lift across the audio spectrum, and keying in the traits Steve was looking for.
Nice job Tony :-)

anthonyTD
13-07-2008, 16:25
Steve kindly brought this amp round for demo last week, Tony (M) has done a fine job in upgrading this amplifier, giving it a nice lift across the audio spectrum, and keying in the traits Steve was looking for.
Nice job Tony :-)
hi mr c,
your comments are much apreciated.
regards,anthony.:)

Marco
13-07-2008, 21:20
Hi Tony,

I heard you guys had a bit of a play - nice one :smoking:

Steve told me he liked your amp, too; just that it did different things to his. I think the only thing I disagree about is your preference for 6550s.

Having conducted some tube-rolling on a few occasions between KT88s and 6550s (of the same pedigree – either both NOS or both new), I always much prefer KT88s - for me they just make music sound more 'alive' and real, and tonally they are pretty much spot on with seemingly little false emphasis at any part of the frequency range, particularly the Svelana cryo'd ones. NOS GECs are simply awesome.

6550s, on the other hand, to my ears tend to sound more 'bland' and 'valvey', but 'valvey' in the traditional sense, with a somewhat cloying, warmth stereotypical of what people who don't know imagine valves to sound like, which for me isn't natural or representative of real music.

Please bear in mind my comments above are not aimed at your amp (I haven't heard it) simply KT88s and 6550s in general. I guess though, as always, much depends on the overall balance of the system used; the circuit and how the chosen output valves are implemented, so I wouldn't dismiss 6550s out of hand - just that to my ears so far they're not for me.

Perhaps you could bring your amp along to the forthcoming Chester 'fest' (I know you travel around the place sometimes) on 23rd August, along with any other interesting bits and pieces, and see how it stacks up against Steve's amp (I'd like to hear this and so would a few others), my Yaqin, and a host of other things that people will be bringing. I always find these events very educational :)

Marco.

Steve Toy
14-07-2008, 01:58
I'd say that Mr C's modded Puresound majors on fluidity, ambience, texture and being unfatiguing; it sounds how a good valve amp really should sound.

The Anthony/TD version does things you just wouldn't expect from a valve amplifier; it is a valve amp for the flat earther in that it majors on speed, dynamics, tightness and agility in the bass with a healthy splash of tonal colour, timbre and solid imaging as added extras.

Neither amp is better than the other and both are an improvement over the stock Puresound A30. The choice is simply a matter of taste. I also prefer KT88s over 6550s.

Marco
14-07-2008, 09:16
The Anthony/TD version does things you just wouldn't expect from a valve amplifier; it is a valve amp for the flat earther in that it majors on speed, dynamics, tightness and agility in the bass with a healthy splash of tonal colour, timbre and solid imaging as added extras.


That is exactly why I like Anthony's designs - because like you say, they don't sound 'traditionally' like valve amps. They marry the best of solid-state and valves and create an addictive cocktail of musical surprises.

This is precisely how my Yaqin sounds now (with minimal 'breathing on' by Anthony) so I'm looking forward to how much better still things will be when he fully 'sneezes' on it! :eyebrows:

The prospect is now even more enticing since he's started to modify his own Yaqin, which I'm sure will throw up some useful observations that can be implemented into my own amp when it gets the full treatment :fingers:

Marco.

Mr. C
14-07-2008, 19:05
Marco,

Clients like different things from products, in a way we all like our sounds our own way.
We have to make a more even handed approach, to suit a wider range of tastes.
I feel the 88's have a more dynamic feel to them with more leading edge bite.
The 6550's I am using are the GE units to me, the best of the real world versions of this envelope giving (for me) much better linearity and even handness.
I can configure the amp to produce a more 'rock and roll feel without to much trouble as well.
Anthony, has made the A30 exactly what Steve wanted in his quest for sound, a usual quality professional job from Mr.M :-)

Marco
14-07-2008, 19:29
Totally agree, Tony. Different strokes for different folks...

Steve said the hi-res downloads were very impressive :)

Marco.