Power transformer sound quality?

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I've been trying different power transformers in a power supply of a DAC and the results are interesting. All of these transformers are of the toroidal variety and are rated 20VA-50VA.

I've tried the DigiKey stocked ones from Talema and Triad. I've also tried Hammond and Avel. And the cheap Anteks. And one made by Schaffner which is fully encapsulated.

Talema and Triad are very similar. Good tonal balance, big soundstage, but somewhat indistinct, grainy.

Hammond and Avel are a step up. Better detail.

But when I tried the Schaffner (20VA), it was insane! The immediacy to the sound was crazy. Hyper detailed/holographic, but the bass/midbass was still very prominent and pleasant.

I did not anticipate this sort of drastic difference. Anyone know why this may be so? Or have any further experience with how different power transformers sound?
 
Does the Schaffner have a shield? What core?

I've been meaning to try the OA core from James in a small power amp. Shield is standard O core transformer(OA type)

I really have no idea. And there's absolutely nothing online that I can find. It's a used one I found and completely encapsulated in epoxy. Looks identical to this:
175137-micromega_concept_dac_1__drive_1.jpg
 
I think it is like "R-core", where the coupling between primary winding and secondary winding is low. When the power line is very dirty, the noise can get into the circuit through the secondary by coupling, and when the grounding is bad, the effect should be very audible.
 
Smaller VA may mean smaller but broader charging pulses, hence possibly less magnetic induction into nearby circuits. If so, the device has been designed with too little distance from the transformer to the audio circuits or too big circuit loops. As is usually the case in these matters, sensitivity to minor component change suggests poor design.

Or it may all be in the mind. Sighted tests can't tell.
 
The "smallest" gets a higher resistance: the psu - it seems - is more caps-weighted.
The smallest, may be, has the thinner wire: "better" hf, more "concentric" current, but "undamped" deeps.
May be, the cheapest has not separated connections in sort of ugly lace, soldered: unnecessary connections.
Regard the direction of current: starts at core and runs core-away, or starts cor-away and runs to core: it results in different induced voltages (AC) at the case: influences the "sound"!
...
 
More resistance (smaller VA) = lower and broader and ROUNDER charging pulses in the rectifier. The result is less stray magnetic flux (running the core at less than saturation) and fewer high order harmonics and current pulses in the rectifier (less induction into surrounding components) and, less HF hash to be dealt with by a subsequent regulator.
No such thing as the sound of a transformer (except the 50/60Hz buzz...), it's the whole circuit. Measure the resistance of the secondary winding and try adding as needed to get the same thing on the others and see what happens.
 
Interesting and essential topic.

Unfortunately, other than anecdotal confirmation that mains transformers can make a substantial difference to perceived sound quality i cannot add much to the thread.

A more systematic approach may be needed though: at least make sure each trafo is appropriately snubberized, so that resonance effects can be minimized.

Contrary to accepted audio lore i never warmed up much to the "sound" of R-cores. In both solid state and tube supplies i always seem to hear their particular sonic signature...

The permalloy Tamura mains trafos appear very intriguing. As they are not being offered with 230v primaries my interest is purely academic. Hopefully someone can share experience with those.
 
Nonsense.
Impossible.
Absolutely unrelated.
Ridiculous.
Placebo effect.

Pick one, more, or all.

We are talking a ***DAC*** here, for God's sake, which is definitely being fed through a regulator, how could wire diameter, resistance, whatever have ***any*** influence?

Only in DIY Audio [c]

That said, this kind of outrageous posts which pop up so often is great (???????) ... in a Darwinist meaning, helping separate those who will survive from those who won't.

Oh well.
 
Nonsense.
Impossible.
Absolutely unrelated.
Ridiculous.
Placebo effect.

Pick one, more, or all.

We are talking a ***DAC*** here, for God's sake, which is definitely being fed through a regulator, how could wire diameter, resistance, whatever have ***any*** influence?

Only in DIY Audio [c]

That said, this kind of outrageous posts which pop up so often is great (???????) ... in a Darwinist meaning, helping separate those who will survive from those who won't.

Oh well.

Inferiority complex? I and many others can hear differences in sound between many different parts. You can't.
 
I'm the first one to eliminate woo, but yes, there can be a sonic signature and it can be proved in blind tests. The trick is not making the appeal to ignorance fallacy and just leave it as a mystical force which makes transformers have a sound, because that's the last thing we changed. It usually comes down to the complete design failing in some way when faced with a particular mixture of circumstances. I once had a DAC which severely affected the sound of a complete system by just being plugged into the mains with it. Turned out the transformer in it was permanently powered and had a very low ESR cap across the secondary and presented a resonant circuit where the rest was affected, the problem was actually traced to the digital source. However, at first the problem was solved by removing the capacitor in the DAC.
So as I said - no, the transformer does not have a sound. When it does, one might start asking, what circumstance did I not cater for in my power supply. It may well turn out that you can't realistically cater for it, and then you simply have to live with the knowledge that different transformers behave differently in a circuit where all else is equal. But then, have I just not made a perfectly obvious observation? Look at even the lumped parameters of a real transformer - in the original example, you can well expect that some are rather drastically different. So there is certainly physics that explains the effects. THe next question should be, how do I optimize my power supply, thinking of it with transformer included, and not with transformer = black box with x volts coming out, in front of my power supply.
 
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