Why does better power = better sound?


Why does improving power quality improve sound quality?

I’m not asking to start an argument about power cords or wall outlets. Please let’s not go there. I’m asking because I’m hoping to learn some technical explanations for the effects of power quality on sound quality. I think I already understand how…

1. greater current availability = greater dynamic range
2. reduction of RFI/EMI = better signal to noise ratio

…but what about these…

3. ???????? = greater perceived resolution
4. ???????? = more realistic instrument timbres
5. ???????? = more precise imaging

Are differences in resolution, instrument timbres, imaging, etc. somehow reducible to current availability and/or powerline noise? If so, HOW are they reducible?

Again, I’m hoping to get into technical specifics, not polemical generalities.

Thanks in advance.

Bryon
bryoncunningham
3 and 4 is same as 1 and 2 - greater dynamic range requires good current delivery and low noise.
Instruments won't have natural timbre thru noisy gear that compresses dynamics.

5 - Imaging is related to noise as well but also to crosstalk, often thru common power supply. Power amp supplies are most likely without line and load regulation with inductive capacitors. Separate power supplies for each channel or even separated amplifiers (monoblocks) will reduce crosstalk.

Jeff Rowland started using sophisticated switching power supplies in latest model 625 (class AB power amp). It switches at 1MHz (easy to filter out) with zero voltage/ zero current switching. It delivers clean voltage that is line and load regulated (not to mention efficiency).

Linear power supply is also a switcher operating at 120Hz where switching appears in worst possible place - at maximum AC voltage. Current is supplied from mains in sharp narrow spikes. Width of these spikes changes with load (switcher's definition). 120Hz ripple is difficult to filter out and requires a lot capacitors. Transformer has to be huge for good performance. In comparison same power transformer operating at 100kHz can be 10x smaller. That's the future in my opinion. Jeff Rowland already uses switching supplies to obtain low noise in preamps (Capri) where efficiency is secondary issue.
…but what about these…

3. ???????? = greater perceived resolution
4. ???????? = more realistic instrument timbres
5. ???????? = more precise imaging
I believe that several before me have already hinted strongly at it - lower distortion equals better resolution, timbres & imaging. So, better power implies "better quality power". It's all about the linearity of the power amp & the ability of the power supply to supply sufficient voltage headroom (so that the voltage excursions do not clip) & dynamic current into the load (so that voltage swings do not clip & sufficient voltage can be created in the drivers so that they in turn can react pistonically assuming that the speakers can handle to volume SPL).
Hi Bryon,

Good comments by everyone above. My take is as follows, the bottom line of which is essentially what Elizabeth said:

"Dirty power" will consist of some combination of harmonic distortion (i.e., frequency components that are at multiples of 60 Hz, sometimes including multiples that reach into the upper treble and beyond), broadband noise (a mix of essentially all frequencies across a wide range), and voltage spikes that occur periodically or intermittently, which in turn will contain a considerable number of spectral components at various frequencies. Inevitably some extremely small but non-zero fraction of all of that spurious frequency content will find its way through or around the power supply of each component and into the signal path.

In addition to perhaps causing a directly perceivable reduction in background blackness, any and all of those numerous frequency components could, to some small extent, intermodulate with the audio signal, resulting in new spectral components at frequencies equal to both the sum of and the difference between the frequencies of any or all of the spectral components of the music and the frequencies of any or all of the spectral components of the noise or distortion. That will occur as a result of non-linearities in the components in the system, and no system is perfectly linear.

Given that the power line spurii and any musical note will BOTH be comprised of a great many different spectral components, the resulting sonic effects as perceived by the listener can be pretty much anything, conceivably including reduced resolution, less accurate reproduction of timbre, and imprecise imaging.

Obviously those kinds of effects will have little if any predictability with respect to either their magnitude or their character, and will be highly dependent on both the design of the system components and the characteristics of the power source.

In principle a power regenerator should eliminate or at least greatly reduce these effects, but as you've probably seen some people report reduced dynamics or other adverse effects when a regenerator is used, especially in the case of power amplifiers.

Best,
-- Al
I've got several cheap Furman power conditioners that I have picked up on ebay for under $50. The challenge is how cheap can I get them. They do improve the sound. So would it pay me to upgrade? Would it pay to go for $200 worth? Don't be concerned about restricting the dynamics in my case. I'd probably be happy in an anechoic chamber.
Al as usual gave a wonderful answer

To view it a bit differently think of electricity or power as water and your electronics as living creatures needing it.
Believe it or not there are only 5 water systems in the U.S. that do not need or are required by state or national standards to use chlorine or other items to clean the water(New York City and San Francisco are two of them). When you don't have to spend time getting things cleaned up so that water can be used it is more energy efficient and easier on all around. Power works the same, when it is cleaner either by power cords, conditioners, magic, or whatever everything flows much more easily and the electronics can finally do the job they were designed for with ease.