View Full Version : Speaker advice to suit Croft phono integrated
I’m currently using B&W 705’s which from what i understand like a bit of power and worked well when using my Arcam power, but thats not an option now?
As much as i love the Croft (i really love it) i’m missing bass at lower listening levels and was wondering if a better suited speaker would extract the best from it?
I really don’t have the cash laying around for a crazy expensive pair of Harbeths or such like, but maybe could scrape together a few pennies for something that fits the bill on a more modest budget.
Any thoughts?
Install a JJECC82. I had limited bass with the standard ECC83.
Thanks Howard.
Is it worth spending a few more pounds on something better than the JJ? If so, what?
Thanks
Hi. I tried lots of 82's. The JJ was the best. I would buy a balanced one.
Howard.
Arkless Electronics
22-08-2016, 10:30
You should be "missing bass at lower listening levels". It's a normal part of human hearing. Hence loudness controls.
You cannot change the amount of bass by changing a valve and also the ECC82 and ECC83 are very different valves. They have the same pin out and so will "work" as a direct substitution but are so different in electrical characteristics that only the one the amp was designed to use will give the correct results.
walpurgis
22-08-2016, 10:41
You should be "missing bass at lower listening levels". It's a normal part of human hearing. Hence loudness controls.
It's funny how the perceived reduction in bass balance as volume is turned down seems to vary with speaker types. Horn speakers, of which I've had a few, don't seem to exhibit this so much, whereas panel speaker can sound like tranny radios at low volume. My Quads did.
Arkless Electronics
22-08-2016, 11:18
It's funny how the perceived reduction in bass balance as volume is turned down seems to vary with speaker types. Horn speakers, of which I've had a few, don't seem to exhibit this so much, whereas panel speaker can sound like tranny radios at low volume. My Quads did.
yes it does seem to vary with speaker type quite a bit.
It's funny how the perceived reduction in bass balance as volume is turned down seems to vary with speaker types. Horn speakers, of which I've had a few, don't seem to exhibit this so much, whereas panel speaker can sound like tranny radios at low volume. My Quads did.
That's almost the effect i get with the B&W's. Maybe i just need to turn it up a bit?
Without wishing to repeat myself, when i was using an Arcam power, it wasn't a problem at low listening levels. The Croft sounds wonderful and I'm very happy with it, but as so many here have had Croft gear i wondered what (budget, for now) speakers work well with it.
I ordered the new valve this morning, so if nothing else it'll be interesting to try it out. It wasn't exactly expensive.
You are not alone on your impressions, Jon. This bloke from Stereophile found the same thing with the 705:
http://www.stereophile.com/content/bw-705-loudspeaker-page-2#AX7sjExh4xXBkr6b.97
'I had two first impressions of the 705. The first was that its sound, while not mellow, was very smooth. The second was that while it didn't seem to lack sensitivity, it did appear to need quite a lot of drive for the music to come to life'
I am only speaking from personal experience I had with the Croft. I had little to no bass in my room and the amp was very shouty until I installed a 82 valve. Multiple emails from Glenn croft suggested that a ECC82 is the way to go with certain speakers. He even said he uses the 82 in his most expensive amps. It made everything natural and balanced for me.
It made me think that the only speaker to suit the JJECC83 in the integrated is the P3ESR. This is my guess work though as i have had no experience of them,just happy owners seem to be around.
walpurgis
22-08-2016, 18:24
The Croft sounds wonderful and I'm very happy with it, but as so many here have had Croft gear i wondered what (budget, for now) speakers work well with it.
If the budget stretches, you may find some used Snell or Audio Note speakers rewarding. Or if you fancy something different, Triangle speakers from France. They are efficient, sound very good and start at sane prices, should be very nice with Croft amplification.
walpurgis
23-08-2016, 15:21
These Snells are offered here: http://theartofsound.net/forum/showthread.php?46220-For-sale-Snell-j-II-speakers-and-stands&p=782290#post782290
They should suit your Sugden very nicely and they are not a huge distance away from you. Very sweet, but lucid speakers. Good sensitivity too.
So, i fitted the JJECC82 this afternoon and…
after swapping the 82 in and out a few times whilst listening to the same tracks again and again, I certainly can say that the bass is much more punchy and tight, and as i listen to a lot of 80/90’s hip hop and rap on vinyl this works very well for me at low volumes.
One thing i did notice was that to get the same volume the volume control had to be turned up a few notches compared to the ECC83. No idea why, unless its because its a new valve?
So happy i am, i’m no longer looking for new speakers for now at least.
Thanks for the advice Howard and Geoff.
And Geoff, it's a Croft, not a Sugden ;)
Arkless Electronics
23-08-2016, 19:32
So, i fitted the JJECC82 this afternoon and…
after swapping the 82 in and out a few times whilst listening to the same tracks again and again, I certainly can say that the bass is much more punchy and tight, and as i listen to a lot of 80/90’s hip hop and rap on vinyl this works very well for me at low volumes.
One thing i did notice was that to get the same volume the volume control had to be turned up a few notches compared to the ECC83. No idea why, unless its because its a new valve?
So happy i am, i’m no longer looking for new speakers for now at least.
Thanks for the advice Howard and Geoff.
And Geoff, it's a Croft, not a Sugden ;)
ECC83 has a gain of 100 and an anode resistance of 62K. ECC82 has gain of 17 and anode resistance of 7K.
There will probably be pretty gross distortion (which you may like! But won't find in anything I make;) ) due to the differences in characteristics and the fact that the values of the resistors used etc can only be correct for one valve type...
Personally I design for accuracy not "contrived" "niceness"
It's a gain of 19 as is printed on the box ;)
And, accurate or not, it suits my needs perfectly. After all, I'm the one listening to the music it makes.
And for what it's worth..
Jez, if you were a little less patronising it'd go no end to helping you sell some of your undoubtedly good products.
I've said it before, but get someone else to do "front of house" for you and do what you do best by making them.
walpurgis
23-08-2016, 20:13
And Geoff, it's a Croft, not a Sugden ;)
Yeah. I know. Dunno how I got that one in there? :scratch: Senility setting in I expect! :)
Ninanina
23-08-2016, 23:09
Jez, if you were a little less patronising it'd go no end to helping you sell some of your undoubtedly good products.
I've said it before, but get someone else to do "front of house" for you and do what you do best by making them.
I think you might have a point there Jon.... :doh: :eyebrows:
After very recently having a Croft integrated in my system, just like your's, I can only recommend the speakers I heard it with and that was my Rega RS3's, they are not that expensive used. I have thrown everything at the Rega's and they just shine and as they work very well with the Oto, at just 10w, I know they are very easy to drive
They do ok with bass at low volumes as well as I very often listen late into the night at low levels and have never thought they miss bass output
I am guessing that the standmount RS1's would sound very similar and be just as easy to drive as the drivers are the same just without the side firing bass unit, or maybe the larger RS5/7's
I also tried the Croft with the LS3/5a's and that was not so successful; that might be down to the fact that I now just don't like them as much as the Rega's I don't really know. I did not try the Croft with my Tannoy's and to be honest that's because every time I exchange the Rega's to the Tannoy's I don't like them as much as the RS3's... and I NEVER thought I would ever say that about the System 800's
My Rega's have been in the system now for a while and I like them more everytime I listen to them... very musical indeed...
Maybe worth a try :)
Arkless Electronics
23-08-2016, 23:15
It's a gain of 19 as is printed on the box ;)
And, accurate or not, it suits my needs perfectly. After all, I'm the one listening to the music it makes.
And for what it's worth..
Jez, if you were a little less patronising it'd go no end to helping you sell some of your undoubtedly good products.
I've said it before, but get someone else to do "front of house" for you and do what you do best by making them.
Please yer self.. only trying to give some valid technical advice. I won't bother you again....
Please yer self.. only trying to give some valid technical advice. I won't bother you again....
I think Glenn Croft is the person to ask for technical advice on his amps. Certainly no gross distortion and spades of accuracy. Have you actually had a croft integrated ?
Arkless Electronics
24-08-2016, 10:41
I think Glenn Croft is the person to ask for technical advice on his amps. Certainly no gross distortion and spades of accuracy. Have you actually had a croft integrated ?
No but I design amplifiers for a living and know precisely what I'm talking about. And no Croft amps are not low distortion or accurate...
If folks don't care that randomly fucking with the design by putting the wrong valves in may take distortion from 0.2% to 3% instantly then fine. It's not my way of doing things.
No but I design amplifiers for a living and know precisely what I'm talking about. And no Croft amps are not low distortion or accurate...
If folks don't care that randomly fucking with the design by putting the wrong valves in may take distortion from 0.2% to 3% instantly then fine. It's not my way of doing things.
If the valve change was suggested by the designer, as in this case, then it isn't really 'randomly fucking with the design'. I agree that Croft amps are not accurate or low distortion but they are not the only highly rated amps that fit that description - that is a whole different argument in any case.
Arkless Electronics
24-08-2016, 12:02
]If the valve change was suggested by the designer, as in this case,[/B] then it isn't really 'randomly fucking with the design'. I agree that Croft amps are not accurate or low distortion but they are not the only highly rated amps that fit that description - that is a whole different argument in any case.
I was not aware of that. It will still mean big differences to distortion and other measured parameters though!
The second part of your post is something I touch on in the zerogain thread in my last post...
Firebottle
24-08-2016, 13:51
If you want to try it Jez this is what the input stage looks like:
http://i601.photobucket.com/albums/tt97/Paramotorpilot/P1040024.jpg
V+ is 250V and the 27K is my suggestion for using an ECC82. 100K anode load is standard.
:)
Arkless Electronics
24-08-2016, 14:07
If you want to try it Jez this is what the input stage looks like:
http://i601.photobucket.com/albums/tt97/Paramotorpilot/P1040024.jpg
V+ is 250V and the 27K is my suggestion for using an ECC82. 100K anode load is standard.
:)
I'm not sure what you're point is here Alan :scratch: The fact that resistors will need changing to give correct biasing and minimal THD is exactly what I'm saying.... At least the gm of the two valves is not a million miles different...
BTW I assume your "Air" power amp is very similar to the Croft series 7? Only so many ways (not many!) you can do a power amp with a single dual triode and mosfet output stage...
What is often missed when considering bass/treble roll off with volume when comparing speakers is the level at which they were voiced. ie, speakers can be designed for a nominally "flat" (anechoically) response BUT only at one specific SPL. Passive (and FIXED active) filters and drive units work together to provide the overall frequency response and you can have a speaker design where bass rolls off subjectively less, because (objectively) the speaker may have been voiced for a lower normalised response. I voice mine for normalised listening levels of between 75 and 80dB (I believe that harbeth and others voice theirs somewhere in that range too).
Add to that speaker efficiency (and NOT sensitivity, although the two often go hand in hand). Depending on the drive unit design and implementation, some lose output in a quite a non linear fashion as it takes a lot of juice to reach a point where they are able to deliver within their ideal frequency profiles. Much below this, they die off rather rapidly. Horns are a good example of a very efficient design where the roll off is a lot more gradual and linear, with roll-off more proportional to input below the normalised (design) listening SPL. Something like ATCs or Wilsons or power hungry big B&Ws typically may roll off frequency in the bass (especially) rather more rapidly with reduced input hence all speaker designs will vary in this respect. There is no universal roll-off which mirrors the F-M efect perfectly. F-M effects should be considered only as our hearing sensitivity profile and not a universal loudspeaker filter profile.
Personally, after many years tinkering with speakers, I have finally concluded that the ideal for my personal tastes is high efficiency speakers with lowish power amplification. A good, big, efficient loudspeaker just sounds more immediate and natural to me, especially at reduced volumes (caveat as always being the design).
In the OP's case, you have to decide what you're after and what levels you mostly like to listen at. The croft is a nice amp, if a bit coloured (I've owned a few and low distortion isn't their forte!) and if that matters more to you than your B&Ws, then a change of speaker to a more efficient design is worth considering.
Arkless Electronics
24-08-2016, 15:18
What is often missed when considering bass/treble roll off with volume when comparing speakers is the level at which they were voiced. ie, speakers can be designed for a nominally "flat" (anechoically) response BUT only at one specific SPL. Passive (and FIXED active) filters and drive units work together to provide the overall frequency response and you can have a speaker design where bass rolls off subjectively less, because (objectively) the speaker may have been voiced for a lower normalised response. I voice mine for normalised listening levels of between 75 and 80dB (I believe that harbeth and others voice theirs somewhere in that range too).
Add to that speaker efficiency (and NOT sensitivity, although the two often go hand in hand). Depending on the drive unit design and implementation, some lose output in a quite a non linear fashion as it takes a lot of juice to reach a point where they are able to deliver within their ideal frequency profiles. Much below this, they die off rather rapidly. Horns are a good example of a very efficient design where the roll off is a lot more gradual and linear, with roll-off more proportional to input below the normalised (design) listening SPL. Something like ATCs or Wilsons or power hungry big B&Ws typically may roll off frequency in the bass (especially) rather more rapidly with reduced input hence all speaker designs will vary in this respect. There is no universal roll-off which mirrors the F-M efect perfectly. F-M effects should be considered only as our hearing sensitivity profile and not a universal loudspeaker filter profile.
Personally, after many years tinkering with speakers, I have finally concluded that the ideal for my personal tastes is high efficiency speakers with lowish power amplification. A good, big, efficient loudspeaker just sounds more immediate and natural to me, especially at reduced volumes (caveat as always being the design).
In the OP's case, you have to decide what you're after and what levels you mostly like to listen at. The croft is a nice amp, if a bit coloured (I've owned a few and low distortion isn't their forte!) and if that matters more to you than your B&Ws, then a change of speaker to a more efficient design is worth considering.
Some very good points there Paul. Surely though if a speaker has been measured to be accurate rather than "voiced" to sound "right" to the human ear at a specific SPL then the speaker designed by measurement is ultimately the more accurate and most suitable for monitoring use? The "voiced" speaker must be acting like a tone control ie if voiced to sound good at low level it must have a built in "loudness" style curve to its response?
Firebottle
24-08-2016, 15:32
I'm not sure what you're point is here Alan :scratch: The fact that resistors will need changing to give correct biasing and minimal THD is exactly what I'm saying.... At least the gm of the two valves is not a million miles different...
BTW I assume your "Air" power amp is very similar to the Croft series 7? Only so many ways (not many!) you can do a power amp with a single dual triode and mosfet output stage...
Just thought if you have a spare hour you might like to knock up a test bed to prove the point. I don't have a low distortion oscillator or distortion measuring kit.
Regarding the AIR I would disagree that it is very similar. I use a much better controlled biasing for the output stage, plus a technically superior driver circuit, both in drive performance and lower distortion.
That's got you guessing eh?
:)
The point is that the speaker designed by measurement will only measure perfectly flat within a narrow band of SPL - if you listen with it at higher or lower spl than that then it will no longer be flat. So a speaker designed to be flat at 80dB will sound like a transistor radio when played at 55 dB
There is a wider point which is where to accomadate the Fletcher-Munson curve in the system. it is widely accepted that a house curve i.e bass at higher levels then gradually reducing level down to the high frequencies is the optimum. But do you boost the bass in the phono stage or DAC, or the speakers, or use eq?
Arkless Electronics
24-08-2016, 15:45
Just thought if you have a spare hour you might like to knock up a test bed to prove the point. I don't have a low distortion oscillator or distortion measuring kit.
Regarding the AIR I would disagree that it is very similar. I use a much better controlled biasing for the output stage, plus a technically superior driver circuit, both in drive performance and lower distortion.
That's got you guessing eh?
:)
How do you set bias etc and check that you are not inadvertently producing 8%THD :scratch:
I wasn't suggesting you had copied the Croft circuit BTW! Just that there are not many options for being different with such a topology... :)
Arkless Electronics
24-08-2016, 15:51
The point is that the speaker designed by measurement will only measure perfectly flat within a narrow band of SPL - if you listen with it at higher or lower spl than that then it will no longer be flat. So a speaker designed to be flat at 80dB will sound like a transistor radio when played at 55 dB
There is a wider point which is where to accomadate the Fletcher-Munson curve in the system. it is widely accepted that a house curve i.e bass at higher levels then gradually reducing level down to the high frequencies is the optimum. But do you boost the bass in the phono stage or DAC, or the speakers, or use eq?
I would hope not!:eek: There will be some change of voice coil resistance with sustained high levels causing heating of the coils. Temperature coefficient of resistance and all that, and this can cause the way the crossover interacts with the load of the voice coil to give small differences in FR.
I'm sure Paul can add some detail to that ;)
I would hope not!:eek: There will be some change of voice coil resistance with sustained high levels causing heating of the coils. Temperature coefficient of resistance and all that, and this can cause the way the crossover interacts with the load of the voice coil to give small differences in FR.
I'm sure Paul can add some detail to that ;)
That's the theory Jez, but many speakers do not exhibit "flat" response at all SPLs. Many are, as Marin suggests, limited to measuring nominally flat over a certain SPL band although many manufacturers will not mention this. Better quality speakers (hence drive units) will have voice coils for example that dissipate heat much more efficiently, so will operate over a wider band to deliver a nominally flat response BUT the confusion is often not the operating band where a speaker will be measurably flat (ie anechoically speaking) but at what SPL they are voiced for in respect of F-M and our hearing sensitivity. Speaker passive filters simply cannot react to hearing sensitivity changes, so the point is that wrt our hearing sensitivity..."flat" means how we perceive the sound at a specified SPL or narrow band. Below that, our hearing sensitivity alters with reduced perception of bass and HF frequencies and above that reference, it alters, with bass and treble energy being the bands in FR where we have gains in sensitivity with increased SPL.
You are right though in that for the purposes of measurement (say, using the B scale weighting) that a speaker system ought to measure nominally flat (ignoring hearing sensitivity changes) over a wide band. The limiting factor at lower volume (again, measurably) is usually speaker efficiency (or more accurately, variable efficiency with power up to a certain point...ie reduced efficiency with reduced power up to a nominal value), and the limiting factor at the upper SPL end is usually how effectively the voice coils (and in some cases certain filter components) can dissipate heat.
There is a further variable which is down to filter quality. Cheap and nasty mass produced boxes of the "back of a lorry" variety will seldom use anything for say inductors which entails more than a few pence worth of cost and may be under-rated wrt power rating, hence you'll get things like core saturation and hysteresis causing FR anomolies.
Like all these things, it's seldom black and white in terms of a blue-print to which all manufacturers deliver. Hopefully that adds a little context.
Arkless Electronics
24-08-2016, 16:32
I think we're pretty much reading from the same hymn book there but it is interesting what you say about reduced sensitivity at low volume.
Of course all speakers should measure flat rather than be voiced.... and audiophiles should have legal rights to play at realistic levels under the Fletcher Munson Act 2016! Get to it Mrs May!
I think we're pretty much reading from the same hymn book there but it is interesting what you say about reduced sensitivity at low volume.
Of course all speakers should measure flat rather than be voiced.... and audiophiles should have legal rights to play at realistic levels under the Fletcher Munson Act 2016! Get to it Mrs May!
....well, reduced efficiency, which isn't the same thing as sensitivity ;)
The Black Adder
24-08-2016, 16:48
How about some classic Celestions. Maybe even some Ditton DL10's? Great speakers and can be bought pretty cheaply. I had some with my Croft pre & power once and was very happy with the bass.
Arkless Electronics
24-08-2016, 17:10
....well, reduced efficiency, which isn't the same thing as sensitivity ;)
Ah now there's another can of worms! It depends how you measure it and interpret it I guess... If sensitivity is output for 2.83Vrms then it goes up with reducing impedance until you haven't enough Ampere/Turns for this relationship to continue I would have thought? Then there is on axis response Vs total power response...:scratch:
How about some classic Celestions. Maybe even some Ditton DL10's? Great speakers and can be bought pretty cheaply. I had some with my Croft pre & power once and was very happy with the bass.
Like these? http://www.ebay.co.uk/itm/Celestion-DL10-speakers-/182228346862?hash=item2a6da7e7ee:g:zTgAAOSwmmxW3V-w
Although those are series 2
The Black Adder
24-08-2016, 18:19
Yup.
They are cracking speakers. Series 2 are perfectly fine. £200... good price.
BTW.. here is my appreciation of them from a while back: http://theartofsound.net/forum/showthread.php?13614-Celestion-DL10-s-A-classic-waiting-to-be-appreciated
I was using some Croft Quad II's at the time but moved to the Croft 7R with them.
Arkless Electronics
24-08-2016, 18:24
If you want to try it Jez this is what the input stage looks like:
http://i601.photobucket.com/albums/tt97/Paramotorpilot/P1040024.jpg
V+ is 250V and the 27K is my suggestion for using an ECC82. 100K anode load is standard.
:)
A quick simulation suggests your 27K anode resistor to be about right. Sim suggests only 34V on anode with 100K anode load.
Gain 23dB (x14) for ECC82 with 27K load and 36dB (x63) for ECC83 with 100k load. With correct resistors the sim suggests not much difference in THD but it tells porkies due to inaccurate modelling of the valves....0.06% THD from ECC82 at 20Vrms out and only 34V on anode:eek:
Yup.
They are cracking speakers. Series 2 are perfectly fine. £200... good price.
BTW.. here is my appreciation of them from a while back: http://theartofsound.net/forum/showthread.php?13614-Celestion-DL10-s-A-classic-waiting-to-be-appreciated
I was using some Croft Quad II's at the time but moved to the Croft 7R with them.
Thanks Josie, thats very helpful :thumbsup:
I've bought them and will hopefully collect on Saturday.
I'm quite excited if i'm honest :D Just need to find some stands to plonk then on now, as i guess my OE B&W stands will be too tall?
The Black Adder
24-08-2016, 18:57
Hey... great news, Jon. Glad to be of some help.
That is exciting :)
Here are the specs from my other thread:
Specifications of the DL10:
Ported, 3-way, 10-inch woofers, 6 1/2-inch midrange and 1 1/4-inch dome tweeters.
Sensitivity at 91db
Frequency response is 45-22 khz. + and - 3db.
Recommended Minimum amplifier power: 10 watts, maximum: open.
Nominal impedance: 8 ohms.
Dimension: 720 x 340 x 300mm
weight is 43 lbs each (20kg's each)
I don't know your stands but if they are just put them on something to get them off the floor for now.
:) All good
Ninanina
24-08-2016, 19:00
Thanks Josie, thats very helpful :thumbsup:
I've bought them and will hopefully collect on Saturday.
I'm quite excited if i'm honest :D Just need to find some stands to plonk then on now, as i guess my OE B&W stands will be too tall?
Well done Jon, nice purchase, they look in super condition as well
I have found the instructions for that range of speakers from Celestion and they mention stands I believe. I have it downloaded as a .pdf file... would you like it ?
Ninanina
24-08-2016, 19:14
Yes please :D
No problem maybe you could PM your direct email address ;)
Ah now there's another can of worms! It depends how you measure it and interpret it I guess... If sensitivity is output for 2.83Vrms then it goes up with reducing impedance until you haven't enough Ampere/Turns for this relationship to continue I would have thought? Then there is on axis response Vs total power response...:scratch:
Sort of. Sensitivity is measured as the on-axis output at 1m distance for 1w or 2.83V input. Efficiency is the measure of acoustic power output by the loudspeaker system divided by the input electrical power, and is usually between 0.002 and 2%. Varying impedance varies the input power to the drive unit but is independent of (ie does not necessarily affect) efficiency.
Both efficiency and sensitivity can be specified for a specific frequency or range of frequencies.
If you have two identical speakers, with the exception that one uses a 4 Ohm voice coil and the other an 8 Ohm, each will require a different voltage to output the same SPL (ie the 4 ohm will require a 2V input and the 8 ohm will require a 2.83v input to have the same output for an identical 1w input value). In this case, they are both identical in efficiency despite the difference in input voltage as it's power that matters.
The relationship between efficiency and sensitivity can be expressed by the following equation:
Efficiency = 10 (to the power of the sensitivity value - 112)/10 but this assumes that the measurement is taken in 2Pi space from an infinite baffle design where the zero dB ref is 10-12watts. As the area of the hemisphere equates to -8dB, and we consider 1 acoustical watt, or 120dB, we get 120-8 = 112dB. This only works for this one condition. Speaker directivity must be considered and stated if describing efficiency properly.
On axis figures are usually stated for sensitivity comparisons for 1w at 1m, usually for a 1Khz reference (but is measured anywhere between 125 Hz and 4KHz). Directivity measurements tell us more about room total power response and also the speaker's off axis response.
Don't confuse room power response with efficiency. Whist they are related, the interest in power response, and more specifically, polar response is more to consider the effects of directivity off axis on the overall response. If a 3 way employs speakers which are signing comfortably in band with low distortion, it may sound ok on axis, but if the selection of the drive units isn't carefully considered, as you move off axis, you can get a step response within a large band across the crossover regions which causes image shift and changes room power response. This can affect distortion values (additional to compression distortion and cone break-up...it is quite a complex mix) and things can start to get complex even for some 2 way designs. The power response is a combination of on axis response and room reflected responses. It is not always advantageous to have a very wide directivity across the full spectrum as the reflected response can introduce unwanted phase distortions and peaks/troughs in overall response due to comb filtering with the direct signal at the listening point. The ideal is to have a wide enough directivity (ie closely matching on-axis) to between 30 and 60 degrees and thereafter a smooth fall off with increased directivity. It depends too on the room and the listening position. Can and worms duly opened up.
It can get confusing especially as loudspeaker sensitivity and efficiency can (and do) vary with frequency.
Not worth fretting over, save that not all loudspeakers behave the same way with a reduction in input power from the "normal" SPL. You asked!;)
Ninanina
24-08-2016, 19:42
Sent by email... :)
With the ECC83 in my room I had what would could be classed as euphoric distorted mids with not much downstairs. The 82 made everything balanced with no perceived distortion. More of a 3d soundstage also and very natural.
Balls to the technical side of things. If it sounds right then leave it alone ! Technical jargon can make you question your sanity as to what you are listening is right or not ,it did with me as there are older threads on here claiming that a 82 should not be used. I used one (recommend be Glenn croft)and it was the most beautiful sound i have had in my living room.
With the ECC83 in my room I had what would could be classed as euphoric distorted mids with not much downstairs. The 82 made everything balanced with no perceived distortion. More of a 3d soundstage also and very natural.
Balls to the technical side of things. If it sounds right then leave it alone ! Technical jargon can make you question your sanity as to what you are listening is right or not ,it did with me as there are older threads on here claiming that a 82 should not be used. I used one (recommend be Glenn croft)and it was the most beautiful sound i have had in my living room.
The circuit I understood was designed for ECC83s, and for the reasons Jez mentions, the circuit design Glenn uses works with the electrical characteristics of that valve, so changing it changes the load on the circuit. You cannot just say "balls to the technical side of things" or there'd be people frying themselves and setting fire to things every day of the week ;). If people don't understand the technical side of things, leave well alone is usually the advice and seek the advice of someone that does. I, for one, would never buy a valve amp off anyone who's rolled valves without understanding the implications of changing valve types. I have seen loads of dead valve amps where that has occurred.
In the case of the valve issues, there's something blindingly obvious that no-one has picked up on yet which might be a cause for the audible distortion and euphoric mids that you mention. I am familiar with the Croft integrated and preamp designs and when they leave Glenn's hands, quite often there's way too much gain for many systems which results in overloading the power amp stage. The easy fix isn't to mess with valve rolling and thereby alter the design, it's to alter the global feedback resistor values between the preamp valves and volume pots. Doing this reduces gain to sensible levels and cures the over loading of the power amp input stage. Glenn does offer this service (or at least used to) and if he valve rolls for other designs then you can be sure that suitable circuit tweaks will be made or that the power supply is rated to take this. The ECC 82 is not a drop in replacement for the 83. It has lower gain and (much!) higher anode current requirements. In this case, the power supply must be rated for the higher anode current if Glenn has advocated using the 82.
The Black Adder
25-08-2016, 10:56
I had Glenn change the gain in my kit for Tannoys especially on my 7. And then he custom built my 7R to suit Tannoy's.
It's one of those things and lots have had the same mod done as many have more than efficient speakers. I went through the in-line attenuator business before I had it done but they just suck the life out of the music.
When the 7R amp was built it was amazingly good.
I had Glenn change the gain in my kit for Tannoys especially on my 7. And then he custom built my 7R to suit Tannoy's.
It's one of those things and lots have had the same mod done as many have more than efficient speakers. I went through the in-line attenuator business before I had it done but they just suck the life out of the music.
When the 7R amp was built it was amazingly good.
Did you replace the 7R with 7monos Jo?
I also had Glenn change the gain in my 25R. I needed a higher gain to get the best out of the DL103 that Dom at NWA rebuilt for me. Glenn changed some resistors and added a MOSFET. However, The Goldbug Brier I am now using has a slightly higher output so I wanted to drop the gain downa little (not too much).
This from Glenn"You could try using 5751's in the phono stage - that will drop the gain by 6dB. ECC81's would give about 10dB reduction.
So I sourced both. NOS Siemens E81CCS and NOS RCA Command series black plate 5751's. The Siemens are very sweet but the RCA's are just phenomenal in terms of bass extension and tone. Oh, and they do drop the gain down.
The Black Adder
25-08-2016, 13:55
Did you replace the 7R with 7monos Jo?
Hi James.
My mistake.. Starting from the start with Croft, I had the Crofted Quad II's that used KT88's. Then I had the 7, upgraded it to regulated (together with the matching pre), then had the gain change, then it was a 25R that was custom build.
After that, yes, I went to some 7R Mono's that were on loan for a short while and then went bonkers with the big valve Tube Distinctions custom build, then (at present) the copper.
The Black Adder
25-08-2016, 14:04
I also had Glenn change the gain in my 25R. I needed a higher gain to get the best out of the DL103 that Dom at NWA rebuilt for me. Glenn changed some resistors and added a MOSFET. However, The Goldbug Brier I am now using has a slightly higher output so I wanted to drop the gain downa little (not too much).
This from Glenn"You could try using 5751's in the phono stage - that will drop the gain by 6dB. ECC81's would give about 10dB reduction.
So I sourced both. NOS Siemens E81CCS and NOS RCA Command series black plate 5751's. The Siemens are very sweet but the RCA's are just phenomenal in terms of bass extension and tone. Oh, and they do drop the gain down.
RCA's do have a great reputation. I'm looking for some NOS 5U4G's for mine.
RCA's do have a great reputation. I'm looking for some NOS 5U4G's for mine.
I have a NOS RCA 12BH7A in my line stage and cannot find anything better yet.
I have a NOS RCA 12BH7A in my line stage and cannot find anything better yet.
See if you can track down a NOS Tungsram 12BH7A - it's the best sounding 12BH7 variant I've tried
I have had a few RCA 12BH7's - the best sounding were the 1950's black plates. GE's were a bit uninvolving, Sylvania a bit more so.
See if you can track down a NOS Tungsram 12BH7A - it's the best sounding 12BH7 variant I've tried
I have had a few RCA 12BH7's - the best sounding were the 1950's black plates. GE's were a bit uninvolving, Sylvania a bit more so.
Yes I agree the GE bit un involving but airy, bit light weight. I would like to try a 1950,s. Black Plate! Heard they are rather good.
Also (surprise) worth checking out are the JJ ECC99 gold pins - very "powerful" Glenn uses the standard ECC99 in place of the 12BH7 - I find the standard ones too bland (same as the standard JJ ecc83
Sent from my iPhone using Tapatalk
Also (surprise) worth checking out are the JJ ECC99 gold pins - very "powerful" Glenn uses the standard ECC99 in place of the 12BH7 - I find the standard ones too bland (same as the standard JJ ecc83
Sent from my iPhone using Tapatalk
I have the standard JJ ECC99 it was terrible!! Can the good pin version really be that better?
I have the standard JJ ECC99 it was terrible!! Can the good pin version really be that better?
Well a command series RCA it aint but it's a step change from the standard
So i picked up the DL10’s today from a throughly decent chap who's owned them from new (i’ve never seen so much audio before, just his second system comprised of a double wardrobe shelved and crammed to the brim with all kinds of wondrous gear) and they’re in decent nick.
He also crawled up into the loft to dig out some free stands (on wheels) for me :)
Pics..
http://i261.photobucket.com/albums/ii52/micared/DL10/FullSizeRender_zpswftggyob.jpg (http://s261.photobucket.com/user/micared/media/DL10/FullSizeRender_zpswftggyob.jpg.html)
http://i261.photobucket.com/albums/ii52/micared/DL10/FullSizeRender%201_zps7rjkfkxn.jpg (http://s261.photobucket.com/user/micared/media/DL10/FullSizeRender%201_zps7rjkfkxn.jpg.html)
As for the sound…
i’m completely blown away with how they sound compared to the B&W 705’s. They really work well with the Croft integrated (thanks Josie :thumbsup: )
I haven’t the jargon to describe what exactly the difference is, but what i will say is that the level of detail, bass and soundstage they portray at low volume is exactly what i wanted.
Now the controversial bit…
After swapping the JJECC82/83 in and out many times whilst listening to the same tracks, all i can say is that (to my ears) the 82 wins by an absolute bloody mile. The music with the 83 just sounds flat, lacks bass and certain instruments just seem to vanish almost like they weren’t on the original recording.
So technically maybe it shouldn’t work, but i have to agree with Howard on his similar observations.
So to summarise, I’m as happy as a sandboy and have spent only £200 on the speakers and £15 on the 82 to get a significantly better sound, who could possibly complain at that?
Who says HiFi has to be expensive?
Not me, that’s for sure :champagne:
walpurgis
27-08-2016, 17:57
(i’ve never seen so much audio before, just his second system comprised of a double wardrobe shelved and crammed to the brim with all kinds of wondrous gear)
Are you sure it wasn't Audio Al you visited? :D
The speakers look great by the way! :thumbsup:
The Black Adder
27-08-2016, 19:03
So i picked up the DL10’s today from a throughly decent chap who's owned them from new (i’ve never seen so much audio before, just his second system comprised of a double wardrobe shelved and crammed to the brim with all kinds of wondrous gear) and they’re in decent nick.
He also crawled up into the loft to dig out some free stands (on wheels) for me :)
Pics..
http://i261.photobucket.com/albums/ii52/micared/DL10/FullSizeRender_zpswftggyob.jpg (http://s261.photobucket.com/user/micared/media/DL10/FullSizeRender_zpswftggyob.jpg.html)
http://i261.photobucket.com/albums/ii52/micared/DL10/FullSizeRender%201_zps7rjkfkxn.jpg (http://s261.photobucket.com/user/micared/media/DL10/FullSizeRender%201_zps7rjkfkxn.jpg.html)
As for the sound…
i’m completely blown away with how they sound compared to the B&W 705’s. They really work well with the Croft integrated (thanks Josie :thumbsup: )
I haven’t the jargon to describe what exactly the difference is, but what i will say is that the level of detail, bass and soundstage they portray at low volume is exactly what i wanted.
Now the controversial bit…
After swapping the JJECC82/83 in and out many times whilst listening to the same tracks, all i can say is that (to my ears) the 82 wins by an absolute bloody mile. The music with the 83 just sounds flat, lacks bass and certain instruments just seem to vanish almost like they weren’t on the original recording.
So technically maybe it shouldn’t work, but i have to agree with Howard on his similar observations.
So to summarise, I’m as happy as a sandboy and have spent only £200 on the speakers and £15 on the 82 to get a significantly better sound, who could possibly complain at that?
Who says HiFi has to be expensive?
Not me, that’s for sure :champagne:
Hey. R-E-S-U-L-T. :stalks:
Looking great. They are magnificent speakers. I loved mine.
Nice set up too! Great stands too!
It makes sense that the 82 sounds better. They are quite sensitive speakers.
Enjoy!
They look fantastic. I bet they give you some proper 'presence' at low volume. Great find there Jon.
These Snells are offered here: http://theartofsound.net/forum/showthread.php?46220-For-sale-Snell-j-II-speakers-and-stands&p=782290#post782290
They should suit your Sugden very nicely and they are not a huge distance away from you. Very sweet, but lucid speakers. Good sensitivity too.
Hi, Geoff.
Coincidentally I am using Snell EII with a Croft SuperMicro II, modded to R spec by Glenn Croft, driving a standard Series7.
Although Glenn claims that he's never been a fan of Audionote and prefers Harbeth in comparison, I am very happy with my Snell-Croft combo. I have recently changed the valves in the Supermicro's phono stage to NOS Tesla E83CC and this has yielded a further, very significant improvement.
Although Croft gear is quite powerful and can drive even insensitive speakers, I believe that the highish sensitivity of my Snells (90dB/W/m) works well with the amps.
Some may claim that the sound of Snells is coloured in comparison to monitor speakers, but I find they have nice balance of naturalness and transparency. For example, I much prefer my Snells to my KEF LS50, which have received numerous great reviews.
I wonder whether there are any other people using Snells with Croft.
If I may ask, what was your experience with Snell and/or Audionote with Croft?
Cheers,
Panos
Floyddroid
30-08-2016, 05:41
Am i missing something? There seems to be an almost cult following of Croft amplifiers. I find it baffling to be honest because unlike a lot of amplifiers out there they don't seem very dynamic, sweet, or anything to my ears. they just seem bland. I think you can do a lot better for the money. As you may have guessed, i am not the biggest Croft fan, though i wouldn't match them up with any B&W speaker. Get shot of the croft and put a decent SS balls amp behind your speakers.
Am i missing something? There seems to be an almost cult following of Croft amplifiers. I find it baffling to be honest because unlike a lot of amplifiers out there they don't seem very dynamic, sweet, or anything to my ears. they just seem bland. I think you can do a lot better for the money. As you may have guessed, i am not the biggest Croft fan, though i wouldn't match them up with any B&W speaker. Get shot of the croft and put a decent SS balls amp behind your speakers.
A Croft integrated with a JJ82 in it has whale bollocks :D
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