"My sense is that most of the inverters that convert DC to AC are really dirty "
That is correct. I am offgrid with solar and from experience trying numerous inverters can say that I have failed to find virtually any brand which outputs an audiophile-grade power. As a result I am forced to use some intense power conditioning including dc offset correction. I do have a Powerplant arriving this week. Of course that is a real piece of nonsense in that now I will be using essentially 2 inverters in series: DC from batteries to AC to DC again inside Powerplant and back to AC.
My present inverter was supposedly a world class, best-in-class, inverter but outputs junk. I called the manufacturer in Texas and they knew what the problem was before I described it. All I had to say was “audio” and they answered “it is screwing up your amp? … our inverter outputs a 25kHz control wave on top of the 60Hz sine wave in order to produce a pure sine wave … just buy a conditioning power strip”.
There are virtually no high quality inverters available. The best have distortion specs over 2% and seem to use class D technology.
Paul, if you are out there anywhere, here is a product idea: simply take a Powerplant and add a 12 volt input. The Powerplants at present create DC internally. I need to tap into that. There is a real need for audiophile-grade inverters and basically PS Audio already has such a product but, as explained, it is not truly usable because of input constriction to AC.
Someday the high quality inverter market will be a billion dollar market. All PS Audio needs is to add that DC input jack to fully utilize their unique regenerator/inverter technology.