What was the rest of the power supply. A quiet but not isolated power supply would provide a lower impedence current path for the circuit with a big trans with a low secondary impedence , than a higher impedence lower current supply. the transformer is part of a whole supply and should be viewed as a system not just one part. In the above cas the larger transformer would sound better than the smaller one . The cause for this is under isolated circuit . It just a mater of how you want to address the use of the positive feedback loop we also call a power supply.
Oh, for the love of potato chips ... (more tangible than god) ...
PUHLLLEEZE folks... no matter what you think, you can not "hear" the difference in a *******' pre-amplifier that consumes less than 5 watts, when driven by a 25, 50, 100 or 200 VA primary transformer, competent bridge rectifier, RC/LC multistage pre-filtration, tight low impedance regulation, cascaded RC post-reg filtering ... and current-balanced preamp design (which balances every positive excursion with a complimentary negative excursion in mirror stage, thus evening out current-draw to near-flat levels).
You cannot. Indeed: Take the transformer OUT of the preamp, and have a couple of terminals whereby you can simply swap transformers with an A/B/C/D switch. Have someone beside yourself switch between them, say 50 times. Or a hundred. Quite simply, you will not be able to make any correlation between size-of-transformer and the performance of the pre-amp, no matter what you think. IF for some reason, you do, and using the "blind" testing, you find others do... then the only probable answer is ... you do not have a competent regulator-and-filter circuit on the INSIDE of the chassis. Period.
It makes so much more sense to put extra design effort into the DESIGN of the power supply, its regulation, and all the ancillary systems, rather than just specifying "more iron", in order to have more "weight" and "apparent value" in a box.
GoatGuy
PUHLLLEEZE folks... no matter what you think, you can not "hear" the difference in a *******' pre-amplifier that consumes less than 5 watts, when driven by a 25, 50, 100 or 200 VA primary transformer, competent bridge rectifier, RC/LC multistage pre-filtration, tight low impedance regulation, cascaded RC post-reg filtering ... and current-balanced preamp design (which balances every positive excursion with a complimentary negative excursion in mirror stage, thus evening out current-draw to near-flat levels).
You cannot. Indeed: Take the transformer OUT of the preamp, and have a couple of terminals whereby you can simply swap transformers with an A/B/C/D switch. Have someone beside yourself switch between them, say 50 times. Or a hundred. Quite simply, you will not be able to make any correlation between size-of-transformer and the performance of the pre-amp, no matter what you think. IF for some reason, you do, and using the "blind" testing, you find others do... then the only probable answer is ... you do not have a competent regulator-and-filter circuit on the INSIDE of the chassis. Period.
It makes so much more sense to put extra design effort into the DESIGN of the power supply, its regulation, and all the ancillary systems, rather than just specifying "more iron", in order to have more "weight" and "apparent value" in a box.
GoatGuy
I have more than a hundred transformers lying around. It is easy for me to plug and play certain transformer to see how they sound. Oh yes, they sound different. I believe that VA (over) rating is not that critical. Quality of the transformer matters most. Those EI with metal casing around windings sound good. Those with paper between winding layers also sound very good (but too big for its VA rating). Of course, R-core is the best that I have compared. And I can compare between R-core of different brands... but VA rating is different... When talking about BOZ preamp (biased at 40mA), my 1A per channel R-core is not enough. The one with bigger VA rating is better.
Could have written the above myself. Minus the BOZ part, as i don't have one.
Yet, some people cannot hear and others choose not to listen. Of course we all know there cannot be an audible difference between competently designed amplifiers, dacs and preamps. Why should power supplies be any different. Trouble is no one can tell you how exactly to design "competently".
OP could have simply tried a few transformers, but creating polemics is so much more fun
Jay, please. Words like "I have hundreds" and can plug them in... is just wonderful, but my good fellow - it sidelines the real point, doesn't it? IF there is some "sonic signature" of a power transformer, then it implies that the regulator is crap... (or, that the transformer output is far too close to the regulator output).
Sorry... I've done dozens of experiments, really, with a combination of transformers and different regulator designs ... and a simple computer-controlled set of relays to switch various combinations on/off in a randomized pattern that even I cannot predict. The results speak for themselves: ONLY those combinations that are underpowered for either the regulator, or for the driven circuit ... or that provide supply voltages in variance with the design spec (either above, or below) have an effect on the pre-amp and/or amplifier sonic signature. And not even once in all the testing, did the effect of over-sized transformers (with correct secondary output) have any statistical relevance at all.
Its one thing to have a belief that it'll make a difference, its another thing to understand WHAT makes the differences. Regulator design #1. Insufficiency of supply #2. Undersized transformers #3. But #1 is in the lead by orders of magnitude.
GoatGuy
Sorry... I've done dozens of experiments, really, with a combination of transformers and different regulator designs ... and a simple computer-controlled set of relays to switch various combinations on/off in a randomized pattern that even I cannot predict. The results speak for themselves: ONLY those combinations that are underpowered for either the regulator, or for the driven circuit ... or that provide supply voltages in variance with the design spec (either above, or below) have an effect on the pre-amp and/or amplifier sonic signature. And not even once in all the testing, did the effect of over-sized transformers (with correct secondary output) have any statistical relevance at all.
Its one thing to have a belief that it'll make a difference, its another thing to understand WHAT makes the differences. Regulator design #1. Insufficiency of supply #2. Undersized transformers #3. But #1 is in the lead by orders of magnitude.
GoatGuy
As a simple and easily understandable example i would use my tube pre. It is choke input after tube rectification and followed by a version of Salas high voltage shunt reg. Noise well below 1mV and about 70v dropping across the cascoded CCS. And would this render the transformer somehow invisible? Or the power cord? I wish it would.
On a side note: is anyone aware of a commercial box like a dac or a phono stage powered from a wall wart which would have astounding, earth shaking bass? In my limited experience with such devices they always appear bright and gutless but maybe there is an exception.
Yes yes yes
External...
(C-R-C-R-C- filtered)
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LOL / Analog_sa
The ability of humans to delude themselves is both amazing and amusing. I ran an expensive, very carefully controlled wine tasting with 24 highly opinionated (and certified) sommeliers ... where I took the time to decant all the wines, clean out the bottles with odorless distilled water, rinsed that out with a bit of the target replacement wine, suffused each bottle with argon gas, then carefully trickled back in a near-full bottle of replacement wine ... all of which were exactly the same. Indeed: it was the blend of the 24 Bordeaux that had come out of all the bottles.
For 3 hours we tasted, and put together panels of comparisons. For 3 hours, not one person commented how "close" they all tasted, or whether there were any differences at all. At the end, as was my predicted inevitable conclusion, enough information had leaked out of the brown-paper wrapped bottles about their origin, that those reputed to be at the top of the line, won. The ones not so easily recognized didn't. And one or two reputed to be skunks, lost handily.
My point wasn't to reveal the duplicity and mendacity of the sommeliers, and their brand-consciousness, but to demonstrate that we are remarkably good at fabricating data-that-isn't-there. As in power cords that are cryo-treated versus single-crystal and so on. To me, scientist, your opinion is in the amusing category... further demonstrating that we are subject to our own prejudices and prognostications.
It isn't hard to build the [1-of-5] computer-controlled choice box, Analog_SA. Try it some time! Its a great project.
GoatGuy
The ability of humans to delude themselves is both amazing and amusing. I ran an expensive, very carefully controlled wine tasting with 24 highly opinionated (and certified) sommeliers ... where I took the time to decant all the wines, clean out the bottles with odorless distilled water, rinsed that out with a bit of the target replacement wine, suffused each bottle with argon gas, then carefully trickled back in a near-full bottle of replacement wine ... all of which were exactly the same. Indeed: it was the blend of the 24 Bordeaux that had come out of all the bottles.
For 3 hours we tasted, and put together panels of comparisons. For 3 hours, not one person commented how "close" they all tasted, or whether there were any differences at all. At the end, as was my predicted inevitable conclusion, enough information had leaked out of the brown-paper wrapped bottles about their origin, that those reputed to be at the top of the line, won. The ones not so easily recognized didn't. And one or two reputed to be skunks, lost handily.
My point wasn't to reveal the duplicity and mendacity of the sommeliers, and their brand-consciousness, but to demonstrate that we are remarkably good at fabricating data-that-isn't-there. As in power cords that are cryo-treated versus single-crystal and so on. To me, scientist, your opinion is in the amusing category... further demonstrating that we are subject to our own prejudices and prognostications.
It isn't hard to build the [1-of-5] computer-controlled choice box, Analog_SA. Try it some time! Its a great project.
GoatGuy
Ok Cobra then that should be fine. But you have no regulator ? I wonder why the difference occur. I prefer E I or Rcore instead off toroid.
317 og 337 do not belong in hifi.
Blanket statements like this will get the engineering team after you for a change
Blanket statements like this will get the engineering team after you for a change
Yes I know but I am sure about this.
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