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I agree with David B. There is no substitute for a good power supply in each piece of equipment. Also, if your house power had a 2 ohm impedance even on one branch circuit, for a 20 amp circuit that would translate to 800 watts dissipation. Not going to happen in a house without calling the fire department.

As far as signal sources, the filter I built for the switcher feeding my Intel NUC would totally eliminate line noise while at the same time providing a huge current sink to operate the equipment through any transients. I have used the same concept for analog equipment power supplies with outstanding results.

Remember that other than AC motors, the vast majority of audio equipment runs on DC power and that is where you want to concentrate efforts to reduce noise and provide surge capability. It is generally simpler and more cost effective.

Tom

I haven't done the regen thing, but I have considered it. Not so much for the possible benefits of regen, but if I can generate 220v/50Hz, I can use the strobe on the Garrard...

Roscoe

_________________
I can explain it to you, but I can’t understand it for you.

CORRECTION
When I said the dc primary coil resistance might be 10 ohms dc or so, I misspoke. What I should have said is 10 ohms is typical resistance when the combined primary and main secondaries are considered. I measure this by shorting the secondaries and applying line-frequency ac to the primary and measuring this short-circuit current. I use a fairly low voltage on the primary, not 120 volts. I measure the resulting current and calculate the resistance. Because of the short circuit, the reactive characteristics are largely removed and what I measure is really effectively a resistance.

When the design of a transformer is optimized, it is common practice to divide the parasitic resistance ( which affects regulation) evenly between the primary and the most important secondary or secondaries if more than one. This is a reflected resistance, per above technique. So, for example, a 1:1 transformer would likely have five ohms on the primary and five ohms on the secondary, for a total of 10 ohms for primary plus reflected secondary. In this case, a dc ohm meter would be expected to read five ohms for each winding.

What seems more important than the output impedance is the output AC waveform distortion.

We normally have about 2% THD from our 120VAC power. At one point it was up to 6% and all the toroidal transformers in power supplies began to mechanically hum. Finally got the power company to come investigate and found dirty contacts in the old mechanical meter base. Cleaned up the contacts, reinstalled it and the power was back to 2% THD and no more hum from the transformers.

The proof was with my Xantrex 2KVA inverter from 12V battery. It's output is 2% THD as well and no hum from toroids.

This was why I bought the PS Audio power regenerators and while they worked it was fine at below 0.5% THD.

All measurements were made with a Fluke 43B power line analyzer.

What did you hear when you went from 6% to 2% to .5%THD

I know there ae raves out there about the PS regenerator. but I have heard complaints that compress the openness of tube electronics. SS do not seem to be bothered

Paul,
Since the AC power was already being cleaned by the PS Audio PPP, no difference in sound with either 2% or 6% THD. Background noise went down as expected with the regenerators.

The PPP was driving all Class A electronics, so I did not expect any difference except the toroidal transformer hum to go down and it did exactly that. If it had been Class AB or Class D amps, I would have been listening for dynamic changes.

The P300 was always for front end and components at the time was Class A as well and just noise floor drop.

At this point it is all PI Audio Group BUSS's for power filtering after the regenerators died. Very happy with them.

Did you ever try a DC blocker on the mains to stop the noise
lots of circuits floating on the web.
https://sound-au.com/articles/xfmr-dc.htm

Did not try a DC blocker. Was easier to solve the problem that was causing the AC distortion once it was discovered.

_________________
Walt

Waveform distortion can cause the average value to no longer be 0V.....

Roscoe

_________________
I can explain it to you, but I can’t understand it for you.