I think we have a God barrier problem here - the mains power outlet is a product of the All Mighty, so perfect in every possible way, not to be questioned - it's just there, totally benign, like a Force of Nature. My concept is that everything that is electrically connected together is just a big circuit - blasphemy, I agree; but there you have it ...
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Thoughts on power conditioners?
- Thread starter Keith_W
- Start date
watchnerd
Grand Contributor
Great, you're on your way to developing a hypothesis.
Now go forth, test it, and let us know the results.
Ummm - I did that 30 years ago, and the results are in - if you want "magic numbers" to satisfy your soul you'll need to go elsewhere ... you see, I'm interested in audio that satisfies me in the listening, and not something that makes me feel good inside because it has great numbers ...
watchnerd
Grand Contributor
Yes, numbers and measurements are good; we can't be you and experience what you experience.
We can be faith-based or empirical.
Yes Frank, we know that non linear supplies create current harmonics and distortion on the lines, the question is, how does our gear handle this on the other side of the dc buss caps. That is where you measure for issues as far as that particular unit is concerned. What happens on the feed side is for each audio device to handle. You can rid the line side of say the second harmonics with an input filter as far as the non linear draw, but again, as Amir said, if the component is high end (we are talking high end here not home theater in a box of course) then we should expect the amplifier to deal with a soft mains line or whatever else the amplifier power supply itself does to the input side. looking at the line side is where I disagree with what you are attempting to say, its of no matter to the component under test or any others attached to it, its about how each amp or preamp or whatever deals with it on its internal power supply output side and if its of consequence or not.
watchnerd
Grand Contributor
I tend to think of a competently designed, generous power supply like a buffer or abstraction layer to the circuitry inside -- everything on the other side of the DC buss is a black box to the circuits inside. They only know about the juice from the power supply.
yep
Your big amp doesn't "drop the voltage" linearly throughout the 60Hz wave.
Tom, the scenario of realistic mains power, combined with realistic transformer and conventional power supplies I investigated about a decade ago, using Spice simulation of the circuitry. Even with still highly ideal parts the impact on the behaviour of the following circuitry was clear - no measurements of the "real world" are needed, even at the 'theoretical' level one can see the issues. At the time I developed a combination of filtering circuitry to deal with it, which I installed on the Philips HT system - the latter had relatively mediocre power supplies, but the added filtering lifted its game to get the good results I posted on. The filtering wasn't perfect, interference still was evident - but it gave me sufficient quality to prove the point.
The headache in all this, always, is the better the playback, the easier it is to hear the presence or absence of the remaining artifacts - leaving a layer of sludge in the sound is sometimes the best way to mask the remainders, it's a form of dithering, effectively.
The headache in all this, always, is the better the playback, the easier it is to hear the presence or absence of the remaining artifacts - leaving a layer of sludge in the sound is sometimes the best way to mask the remainders, it's a form of dithering, effectively.
I know what you are trying to say there Frank.
That would show up on the output of the power supply, not its input. You can't push non-linearity upstream. The upstream system itself needs to be non-linear to power draw to generate more harmonic distortion.
But the best feeling comes when they are both true. It gives you confidence in your conclusions. That gives you durability. How do you know if I listened to your system I would conclude the same thing you have? What if I think it is junk. What then?
Compare your filtering to what is inside my amplifier:
This is a mono-block so one channel. The power supply is at the bottom with 190,000 microfarad of capacitance. The on each side of the amp module you see an array of smaller caps totally over 100,000 microfarad. There is also a massive transformer. All of this powers a very efficient four-way interleaved switchmode amplifier. The peaks therefore are easily serviced out of the capacitor filter bank.
So if that is looking for in a system, it is all there. Any conditioner in front of this amp will limit its performance, not improve it.
Note that I was talking there of the impact of mains power noise affecting SQ - not of my subjective reaction to what I think is good sound.
Mark Levinson No 53.
I note this review, http://www.stereophile.com/content/...monoblock-power-amplifier#pII2jwxHKtVLC9GH.97. In which the reviewer noted some characteristics to the sound - I take it you wouldn't agree with them ...
I see.
Fify
Speedskater
Major Contributor
Low AC power line source impedance is good.
Low noise is good. That would be spikes, surges and dips. That is all things not harmonically related to the power line frequency.
But a near perfect sine wave is nonsense. In a power amplifier, a linear AC supply current waveform is nothing but harmonic distortion (let's skip what a SMPS waveform is). Any audio circuit designer worth his salt can design a good AC supply section. If it takes magic AC power to make an audio component sound good, well then it's a poor component. Just quietly sell it on E-bay.
