I have never heard that before. Just wish some one would try this. Its sooo easy to do!
Max Planck also said, “Science cannot solve the ultimate mystery of nature. And that is because, in the last analysis, we ourselves are a part of the mystery that we are trying to solve.”
What? S/N ratio in this thread too poor to spot post #29? 😀
I did put spare EI transformer of mediocre quality on top of exactly the same transformer in working PS, and measured voltage, noise, ripple and harmonics. There was no measurable change while adding, removing or rotating additional transformer. I could measure some other parameters as well, but I see no point.
Did you listen to the equipment with the new transformer on the existing one? I'm glad you measured, but listening is what we do with our equipment, I mean that is why we have it, right?
Sure. But if there is no measurable difference it is exceptionally unlikely that any difference we might perceive is due to a change in the equipment or the stimulus that reaches our ears. It's vastly more likely that any perceived change is due to a change in perception due to the many psychological influences on perception.
Tom
Tom
If we hear a change but our measurements don't tell us what changed, maybe we are not yet able to measure the right thing.
Let me repeat my take on your experience. If you can hear a change with the additional core, no matter for the better or the worse, then your system most likely be problematic, may need to reorient, relocate or shield the power transformer to rectify the problem. What happened in your case is expected not to happen to other non problematic amps. Tomchr went further by stating presence of additional core close to any power transformer should not produce perceivable change which means you are hearing things which is not there (which I disagree).
In case that you really do hear a change then that change is measurable.
Measurements were taken at circuit assembled on the bench for that purpose. There was one test amplifier under development attached to measured PS. However, what happens after PS rectifiers is attenuated 90 dB at amplifier output. I suspect that is a smidge beyond my hearing abilities. 🙂
With no measurable differences at PS output, it would be silly to arrange serious listening.
I really hear a change on many different transformers, but I do not know what measurement will explain what I hear. I was hoping that by posting this someone here could help explain the heard difference.
I do not agree. You could hear a improvement. How hard would it be to do this? I bet not very hard.
Do at FFT using your sound card, REW and an attenuator. Look for change in mains related 50 &100Hz IM products.
I recommend you to find some ferromagnetic material to shield the transformer and compare.
You could. You could also not. Have a look at the bottom paragraphs of Post #118 for my suggestion of an experiment. You can also look into ABX Experiments. Ideally, the experiment should be double blind, but that gets tricky unless you bring in people who are completely naive about the experiment.
Tom
When I was still an A-Level student, many many eons ago, I did one of my student-work experiences in a power station. This thread's title of a transformer helping another one, reminds me of my visit of the station generator hall. Generators had what are known as auxiliary generators which generated a DC voltage to energise the rotating electromagets of much larger AC generators.
An auxiliary power supply to an amplifier would supply very clean and stable voltages to the most sensitive parts of an amplifier like the input and VAS. The actual much more powerful power supply would supply power to the autput stage.
Please, note I never met the idea above of using two separate power supplies to power an amplifier. The case of a power station generator using another one as an auxiliary (excitor) is something which is actually used and makes logical sense.
An auxiliary power supply to an amplifier would supply very clean and stable voltages to the most sensitive parts of an amplifier like the input and VAS. The actual much more powerful power supply would supply power to the autput stage.
Please, note I never met the idea above of using two separate power supplies to power an amplifier. The case of a power station generator using another one as an auxiliary (excitor) is something which is actually used and makes logical sense.
Now we're getting somewhere. If you end up finding a difference, repeat the experiment with a brick (or similar non-ferromagnetic mass) to see tease out if the difference is due to the interaction with the transformer or due to microphonics.
Tom
Can you describe how sound changes with additional core?
Next, try to explain what is needed in physical world for that actual sound change to exist.
In example, if you hear more clear treble, either there is amplitude change at HF or there is increased level of odd harmonics. If you hear more solid bass punch, maybe PS voltage sagging under dynamic load is reduced. And so on.
Whatever change in sound really exists it must have physical cause which is easy measurable.
We're aware of the axiom. It may behoove you to quote it? Perhaps it will shed some light on our apparent confusion?