If someone wants to spend $10K on rectifier tube or $20K on speaker cable and feel happy in his own universe, fine. But when they show up on audio forums and start posting claims about how much better those things sound, they should accompany those claims with evidence but they don't because typically,
1. They can't find any but still want to brag about it.
2. They don't know what evidence is.
3. Some are shills for retailers that sell those things. 🙄
1. They can't find any but still want to brag about it.
2. They don't know what evidence is.
3. Some are shills for retailers that sell those things. 🙄
Chris, I made the statement that measurement is no substitute for human hearing w.r.t. ideal placement of microphones for a recording. Right or wrong?
I agree, that is a totally different kind of question, and one that is concerned with artistic nuances, subjective judgements, etc, etc.
My comments were exclusively concerned with the performance of audio amplifiers, and whether or not there could exist genuine audible differences between amplifiers that could not be correlated with scientific measurements.
Chris
Yes, they can. They all could. Maybe time to read the research again. They just didn't prefer the Strad or Guarneri.
Whose research? One says: No-one can hear the difference reliably. The other says a trained ear can do it easily. Although the first link doesn't actually cite a study.
I've found this (easily heard):
Quantifying Quality: Violin Sound Analysis | FALCONIUM
(no difference)
Stradivarius Fails Sound Test versus Newbie Violins: Scientific American Podcast
Hi!
Wow, 13 pages of discussion about rectifiers 😉
This is quite symptomatic of the audio world: A lot of focus on rather unimportant details.
I stopped worrying about rectifiers a long time ago as long as it's low noise and preferrably hollow state feeding a choke input supply and being fed by a high quality power transformer.
Recently a friend was ranting about the big differences he hears between brands(!) of 5U4 rectifiers in his amp. A lot of this is going on between the ears! He was probably not aware how much cross branding was ongoing and that the tube might well have been manufactured by another company than was stamped on it.
When I visited him, I was rather dissapointed of the sound of the amp altogether. Why bother about the tiny differences a rectifier might make in an amp which is shitty sounding anyways 😛
I would always be suspicious if rectifiers cause a different sound. That's rather a sign of a poor design rather than the resolution strenght of the amp. If different brands even of a rectifier cause a different sound, anything will have an impact on the sound: mains supply fluctuations, aging of the tubes, room temperature, humidity or just looking at it too long 😉 I rather have an amp which sounds stable whenever I turn it on or when I change tubes.
Best regards
Thomas
Wow, 13 pages of discussion about rectifiers 😉
This is quite symptomatic of the audio world: A lot of focus on rather unimportant details.
I stopped worrying about rectifiers a long time ago as long as it's low noise and preferrably hollow state feeding a choke input supply and being fed by a high quality power transformer.
Recently a friend was ranting about the big differences he hears between brands(!) of 5U4 rectifiers in his amp. A lot of this is going on between the ears! He was probably not aware how much cross branding was ongoing and that the tube might well have been manufactured by another company than was stamped on it.
When I visited him, I was rather dissapointed of the sound of the amp altogether. Why bother about the tiny differences a rectifier might make in an amp which is shitty sounding anyways 😛
I would always be suspicious if rectifiers cause a different sound. That's rather a sign of a poor design rather than the resolution strenght of the amp. If different brands even of a rectifier cause a different sound, anything will have an impact on the sound: mains supply fluctuations, aging of the tubes, room temperature, humidity or just looking at it too long 😉 I rather have an amp which sounds stable whenever I turn it on or when I change tubes.
Best regards
Thomas
+1
Well if your prefer a hollow state rectifier. Your are implying that the rectifiers matter.
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Hi Bas,
Yes, depending on the implementation of the power supply, the class of rectifiers can matter a lot. With class I mean like: silicon diodes (fast recovery, Schottky, etc) vacuum diodes (directly or indirectly heated) or gas filled diodes.
Depending on the overall design these differences can be large or rather small.
Each of these classes will have drastically different voltage drops which needs to be accounted for.
What I was referrigng to in my earlier post was differences between rectifiers of the same class, or even differences between brands or vintage of the same recitifer type
Thomas
Yes, depending on the implementation of the power supply, the class of rectifiers can matter a lot. With class I mean like: silicon diodes (fast recovery, Schottky, etc) vacuum diodes (directly or indirectly heated) or gas filled diodes.
Depending on the overall design these differences can be large or rather small.
Each of these classes will have drastically different voltage drops which needs to be accounted for.
What I was referrigng to in my earlier post was differences between rectifiers of the same class, or even differences between brands or vintage of the same recitifer type
Thomas
Is it not too great a leap that different brands of GZ34 may have RFI issues that most scopes and measurements don't have the bandwidth to pick up?
Do they pick up garbage from the mains, or how do they deal with transformer A vs B when mains DC is vibrating the B+ transformer?
I think it is plausible for instance that a GZ34 brand X could send a WE437 into oscillation fits while brand y doesn't. Especially if they are in the same chassis no matter what the regulation.
Rectification is a process of high bandwidth, an area audio measurement can be questioned, because there are too many variables from the lab, to the proto, to the manufacture, to plugging the product into your home.
That said these are unusual cases, and most of the time these issues don't crop up because we have learned to design around them, but I don't think we can completely dismiss the issue. I's worth it to pay the extra for japanese GZ34 over new JJ G34's, they aren't pork bellies.
Yes, it is. 200MHz is a pretty typical scope bandwidth, and even 1/4 of that is insanely higher than the switching time of a vacuum rectifier.
Mercury is a different issue, but that's not the question here (and it's relatively easily dealt with).
Very unlikely. I can't think of any mechanism which might cause a GZ34 to do anything strange at frequencies above low HF (i.e. a few MHz) so well within the capabilities of ordinary test equipment to detect.regal said:
I think this is very implausible. However, if your amplifier valve is singing at VHF/UHF (which it shouldn't be, of course) then it is possible that some rectifiers might be better or worse at producing modulation hum from this. So the rectifier is not the cause of the problem, but may be better or worse at exposing the problem.
Depends what you mean by high. I would guess not much above a few hundred kHz, for a valve rectifier. You might get higher frequencies from semiconductors because of charge storage effects.
Valve rectifiers were routinely used in communications equipment and test equipment, which are far more sensitive to RFI problems than any audio amplifier. Modulation hum is the main issue, but that only applies to items containing an RF oscillator - not relevant to most valve audio.
Hi!
As others have mentioned already, this is extremely unlikely. And if it really would be the case that would indicate a very instable amp design and layout. Then all kinds of things could cause that effector others
IMHO that would not be an amp worthwhile to spend lot's of money on rectifiers for. Rather find the reason for the sensitivity and fix it
Best regards
Thomas
As others have mentioned already, this is extremely unlikely. And if it really would be the case that would indicate a very instable amp design and layout. Then all kinds of things could cause that effector others
IMHO that would not be an amp worthwhile to spend lot's of money on rectifiers for. Rather find the reason for the sensitivity and fix it
Best regards
Thomas
I thought I had heard every bit of audiophile craziness but a claim I heard fairly recently that a valve rectified and valve regulated power supply for a CD transport made an enormous difference sonically rocked me back on my feet nearly as much as a discussion of the quantum properties of tonearms.
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