Ignorance Is Bliss.....
The engineer types I've met who for example, insist that speaker wire cannot make a difference crack me up too.
In these cases, I do not even bother to explain to them why this can be.
I find it easier, and more amusing to just allow them to continue in their blissfull ignorance than to explain electrics and nfb amplifier theory.
I find it amusing that such students blindly believe bigoted lecturers that have told them furphies like that one.
best wishes for the festive season,
Eric.
The engineer types I've met who for example, insist that speaker wire cannot make a difference crack me up too.
In these cases, I do not even bother to explain to them why this can be.
I find it easier, and more amusing to just allow them to continue in their blissfull ignorance than to explain electrics and nfb amplifier theory.
I find it amusing that such students blindly believe bigoted lecturers that have told them furphies like that one.
best wishes for the festive season,
Eric.
zeno said:Has anyone ever compared a DIY Pass with a real one from the hands of the One and Only?
Maybe one gets the same sonic difference, due to parts, mechanics etc.
Marc
Having spent many years 'listening' to the differences in sound caused by alternative components and especially electrolytic capacitors, just using a different make from Nelson's production caps in the signal path will have a marked effect on the overall sound.
I am certain many DIYers would be quite amazed at how the characteristics can change due to these differences, and before any objectivists shoot this down, please take the time and trouble to try it out first, as I have done on very many occasions.
Regrettably all electrolytics 'sound' poor (i.e. they simply do not *sonically* replicate the input faithfully at their outputs, whatever any test gear may say), but some are much worse in their effects than others, and any signal path or feedback DC blocking cap, will reveal these abberations the most obviously.
One of the reasons I have not yet tried any of Nelson's designs (attractive though they certainly are) is that so many of them use these awful sounding electrolytics in such critical places.
I therefore await any further exposures from Nelson on the SOZ circuits, which avoid signal path electrolytics and these problems altogether, before I build one of his otherwise exemplary designs.
There is no component in my entire audio system which has not been chosen after extended individual listening tests, and wherever possible, I avoid all electrolytics like the plague.
The only ones worth using in my opinion (and if I haven't tried them all, I have certainly tried dozens of them) are the obscenely expensive non-polarised Black Gates, which don't sound too bad, and I will not even use these in the signal path.
However, regrettably, in any worthwhile value they are far too expensive to use, and even they are not as good as no cap at all.
No doubt there will be many who will cite examples of wonderful sounding gear which do use (awful sounding) electrolytic caps in their circuits, but, if it was possible to eliminate these caps somehow altogether, I guarantee that the amp would sound better and be more accurate and faithful in its reproduction of the original sound.
Anyone with a SS conventional feedback amplifier with an output DC nulling pot can try the effect with a little care.
Simply bypass the DC blocking feedback cap temporarily after hooking up a meter at the amps output, and quickly adjust the output offset to as close to zero Volts as possible. In reality, although being a perfectionist I like to keep it down to less than 10mV in my own amps, even an offset in the hundreds of mV's shouldn't cause any problems in the short term, and without the blocking cap in circuit, it will soon drift with temperature, anyway.
If you then play a favourite piece of music, my guess is that you will be astounded by how much nicer it sounds, all due to the removal of the wretched cap.
Even if you have previously modded the circuit as I did many years ago to allow the use of high quality plastic film caps here, you will still hear a marked improvement in the sound, and you will not thereafter wish to go back to how it was before.
I don't suggest you try this test for an extended period, and it is safer to leave the meter connected to keep an overall eye on things, although during the playing of heavy sounds, the DC reading will change up and down of course. It is merely intended to illustrate to the doubters amongst us, that the cap itself affects the sound quite substantially.
If you have a half decent system and a reasonable pair of ears (even casual listeners, who don't care about audio whom I have demonstrated this effect to, have all noticed the improvement straight away) you will realsie just how much (bad!) influence such capacitors do have on the sound of audio gear.
Therefore, unless one just happens to be extremely lucky in their choice of electrolytic and have found one that I haven't yet come accross, I believe that the results will be marred substantially from how they could be, and unless the same make of cap were to be used in both amps which are being compared, you simply will not be making a true and fair comparison between them as far as pure circuit design is concerned.
I hope that many of you will try out what I have done and that it will lead ultimately to better sounds from your audio equipment.
dshortt9 said:
If I understand it correctly, a transformer will create linear and harmonic distortions. An electrolytic capacitor will create non-linear distortions (due to dielelectic absorption, for example), that are also not harmonically related. Thus, a little bit of capacitor distortion can sound really bad, while a lot of transformer distortion (if second order, for example) will give a warm and, to some, pleasing sound.
Jeff, You hit the nail on two things. First, the fact that capacitors add some distortion of theor own....each is different. And second, the fact that 2nd order harmonic distortion is the more desriable distortion if there has to be any. In fact Nelson's amps meet that criteria as they are for the most part direct coupled and generate primarily only 2nd harmonics......The capacitor issue is why I abandoned tubes all to together.....very few tube circuts are all direct coupled and the caps thing is always an issue. Mainly I always felt that I was listening to the caps....not the circuitry.....so which caps shall we use today I'd ask myself........
Mark
Mark
My system is fully differential from the cart to the speakers, so the effects of the PSU are greatly reduced anyway, and there ain't a lytic in sight.tortello said:
My comment was about Mark giving up on tube gear because of a couple of signal path caps, how many SS designs are there without a lytic anywhere?
Best way to minimise their impact is throw them in the bin. Don't need any fancy circuitry then.
Cheers
Mark.
I fully agree with your suggestion that most of the time you feel that you are simply listening to the sound of the caps when they are used in such a way in most audio gear. It is an unfortunate fact, whether people care to accept it, or not. They are welcome to ignore it at their peril, and to their disadvantage!
Although dshortt9 clearly doubts the truth of what some of us have (reluctantly) come to accept, the inconvenient fact exists, and I am no more happy with it than he is.
I would have been more concerned over his rather fatuous reply, however, if he had stated that he had carried out the test I suggested, and subsequently didn't agree with my observations.
Tortello has raised an equally valid point, although as I felt I had written enough in my earlier post, I decided not to refer to PS caps there.
Power supply caps do have a very similar effect on the sound, but in my experience, it is a little less apparent, than with signal path caps.
Interestingly, in my own power amp, I have 8 discrete regulators in the PS and if I make changes to merely the HF compensation caps (low value, high quality, plastic films used for stability in the feedback loops of the regs), which is about as far removed from the signal path as you can get in any amp, the overall sound of the amp changes quite noticeably.
It really is a minefield!
The point I attempted to make in response to another post about comparing various designs, and in particular the question of using similar components to Nelson in copies of his designs, was unfortunately missed by dshortt9.
It was that the differences in sound due to the alternative circuit topologies of *well designed* audio gear, will be mostly swamped (or at the least, very severely masked) by the unfortunate choice of a typical electrolytic in the signal path.
Also, for the same reason (unless one has constructed an amp of Nelson's design with *exactly* the same components etc, throughout as he uses in production himself) it is not reasonable to compare say Pass amps with another manufacturer's offerings, and make any generalizations such as that the Lamm is better, which seemed to me to be at the root of this entire thread.
The original poster of the thread, did make it clear that it was a copy of Nelson's design, not an actual Pass made product, but I still felt that many interested DIYers might be (albeit unwittingly) somewhat mislead by what had been said.
Some DIY copies will by chance sound better than the originals, and some will definitely sound worse (irrespective of the loving care shown in their hand-built construction) especially if the builders believe (as I used to do, many years ago) that almost any reasonable quality electrolytics will do.
As I have never seen any reference to such a simple but consequential matter as this, I hoped to offer some assistance to those who are serious about obtaining the best possible results, by drawing attention to just one such issue.
I also suggested a reasonably easy test for any doubters to try, so that they could judge for themselves the truth (or otherwise) of what I said, and, if they are fortunate enough to discover that the difference does not matter to them, they have found what has eluded me for years, i.e. the perfect sounding electrolytic capacitor.
I fully agree with your suggestion that most of the time you feel that you are simply listening to the sound of the caps when they are used in such a way in most audio gear. It is an unfortunate fact, whether people care to accept it, or not. They are welcome to ignore it at their peril, and to their disadvantage!
Although dshortt9 clearly doubts the truth of what some of us have (reluctantly) come to accept, the inconvenient fact exists, and I am no more happy with it than he is.
I would have been more concerned over his rather fatuous reply, however, if he had stated that he had carried out the test I suggested, and subsequently didn't agree with my observations.
Tortello has raised an equally valid point, although as I felt I had written enough in my earlier post, I decided not to refer to PS caps there.
Power supply caps do have a very similar effect on the sound, but in my experience, it is a little less apparent, than with signal path caps.
Interestingly, in my own power amp, I have 8 discrete regulators in the PS and if I make changes to merely the HF compensation caps (low value, high quality, plastic films used for stability in the feedback loops of the regs), which is about as far removed from the signal path as you can get in any amp, the overall sound of the amp changes quite noticeably.
It really is a minefield!
The point I attempted to make in response to another post about comparing various designs, and in particular the question of using similar components to Nelson in copies of his designs, was unfortunately missed by dshortt9.
It was that the differences in sound due to the alternative circuit topologies of *well designed* audio gear, will be mostly swamped (or at the least, very severely masked) by the unfortunate choice of a typical electrolytic in the signal path.
Also, for the same reason (unless one has constructed an amp of Nelson's design with *exactly* the same components etc, throughout as he uses in production himself) it is not reasonable to compare say Pass amps with another manufacturer's offerings, and make any generalizations such as that the Lamm is better, which seemed to me to be at the root of this entire thread.
The original poster of the thread, did make it clear that it was a copy of Nelson's design, not an actual Pass made product, but I still felt that many interested DIYers might be (albeit unwittingly) somewhat mislead by what had been said.
Some DIY copies will by chance sound better than the originals, and some will definitely sound worse (irrespective of the loving care shown in their hand-built construction) especially if the builders believe (as I used to do, many years ago) that almost any reasonable quality electrolytics will do.
As I have never seen any reference to such a simple but consequential matter as this, I hoped to offer some assistance to those who are serious about obtaining the best possible results, by drawing attention to just one such issue.
I also suggested a reasonably easy test for any doubters to try, so that they could judge for themselves the truth (or otherwise) of what I said, and, if they are fortunate enough to discover that the difference does not matter to them, they have found what has eluded me for years, i.e. the perfect sounding electrolytic capacitor.
Re: Brett in paraqdise
Currently my system is reduced to about a thousand electronic components scattered across my livingroom coffee table, as I've had a flurry of activity on it, because I was lent some parts, and because I found I am able to build the amp I want because some parts I thought unsuitable, are actually OK.
This is what it will consist of on Monday, I hope.
Phono1: Denon 103S -> VSE RTP3C phono section with MAT02 as bottom of cascode -> 12B4A loaded with LL1660PP in 2.25+2.25 : 2+2 -> selector -> S&B TX1022 TVC -> ECC99 -> LL1635 -> (currently) KT88 trioded (soon 813) -> LL1620PP
(the LL1660 are borrowed) The two caps are the couplers at the output of the phono section. There are no cathode bypasses.
I also have a pair of VSE PP2C poweramps.
There will soon be another phono stage for the Decca (I canabalised the last one for parts), and for the Win Labs SDT10, so 3 phono in total, with the WL battery powered in a seperate case.
SACD player and R2Rs go straight to the selector. All AV inputs go via a dedicated selector before the main selector, isolated by 1517 transformers (1:1 or 1:2).
The PSU for the preamp is full of iron and weighs about 20kg without case.
Cheers
Hi Reinhard,reinhard said:
Currently my system is reduced to about a thousand electronic components scattered across my livingroom coffee table, as I've had a flurry of activity on it, because I was lent some parts, and because I found I am able to build the amp I want because some parts I thought unsuitable, are actually OK.
This is what it will consist of on Monday, I hope.
Phono1: Denon 103S -> VSE RTP3C phono section with MAT02 as bottom of cascode -> 12B4A loaded with LL1660PP in 2.25+2.25 : 2+2 -> selector -> S&B TX1022 TVC -> ECC99 -> LL1635 -> (currently) KT88 trioded (soon 813) -> LL1620PP
(the LL1660 are borrowed) The two caps are the couplers at the output of the phono section. There are no cathode bypasses.
I also have a pair of VSE PP2C poweramps.
There will soon be another phono stage for the Decca (I canabalised the last one for parts), and for the Win Labs SDT10, so 3 phono in total, with the WL battery powered in a seperate case.
SACD player and R2Rs go straight to the selector. All AV inputs go via a dedicated selector before the main selector, isolated by 1517 transformers (1:1 or 1:2).
The PSU for the preamp is full of iron and weighs about 20kg without case.
Cheers
Nelson Pass said:
The distortion is always harmonically related unless it is
intermodulation distortion. There is a direct relation between
IM and THD, and any additional components are called noise.
Hi Nelson,
I wondered if you might comment on this thread.
Irrespective of what the relationship is with regard to distortion or noise or whatever, the resulting difference between "what goes into an electrolytic cap" in any signal path situation, and "what comes out", is sufficient to make them very undesirable in these locations.
We all know that the effects can be ameliorated to some extent by feedback etc., but I still say they should not be used in these locations, whenever possible, to avoid all likelihood of harming the integrity of the audio signal.
I have little doubt that with your experiences and resources, you have come accross some of the (few!) less lousy sounding electrolytics, and that you use these in your production, in the same manner that you use better sounding rectifier diodes.
Unfortunately, hitherto, very little publicity seems to have been given to this undesirable situation from what I have seen, and most DIYers have to use blind faith in such cases. Even if they were aware of the problem, few DIYers would have the resources to try out many different makes of electrolytics for themselves.
The regrettable result is that, mostly, their amps will probably not sound as good as they might, simply due to an unlucky choice of signal path or feedback cap.
I know you recognise this from an earlier email from you, although you don't get so hung up on the matter as some of us do, but *please* when are you going to do us all a favour, and share some of these promised revelations over 'upgrades' to the SOZ circuits, which avoid this issue altogether?
I am currently planning how to make some holes in the ceiling of my bungalow, to make room for the wicked El-Pipeooooooooo jobs!!
Thanks, as always, and a happy and prosperous New Year to you.
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