Going Battery Powered

Are there any Class-D amps with "warmer tube" SQ that can be powered with DC?

The OP seemed to ask in the original post if bypassing the AC to DC PS in his equipment and connecting a battery would benefit his playback. 

A battery power supply converting 12 volt DC to 120 volt AC is not the same topic.

Ron Sutherland use to use battery power for his phono stages.  He says he gets better performance with 120 volt AC power supplies.   I don't see many equipment manufacturer use battery.   Some do.  Dartzeel on the preamp.  My Lino Channel D phono pre.  They are used.  I don't know of any amps that use them.

Batteries are current limiting.   Lithium less so than led acid.   A deep cycle lead acid is very slow to release power.  

There are so many variables you can not make a carper statement one is better than the other. You could modify a piece of equipment and make a judgement on that one piece.  

As to wall power vs a battery, most people have crap wall power.  Even those that add circuits usually have some issues.  An isolation transformer is also a benefit.  But you need a good one.  Not some deal you scored off ebay. 

Getting your electrical to a premium level is money.  So is a true battery system providing 120 volt to a rack.  I calculate it to about $18k in parts if your  going to drive a whole home system.  The battery are the lion share.  The inverter is a critical link.  

And after all that, you still have not addressed RF that is entering through the equipment itself.  

FWIW.  The best inverters I have seen have about 3%thd.  Depends on the load to some extent.  The worst houses I have measured have about 5%thd.  Most are about 3%.  

Low frequency inverters give better peak power than high frequency.  Never use a modified sine wave inverter. 

Remember, lithium batteries do have a tendency to burst into a fire ball durring charging.  Don't buy some cheap piece of crap and use it in your house.  Buy a good one.  And get the $500 charger they want to sell you that is made for that battery.

You can also just buy a Tesla powerwall and plug directly into it.  Or a Stromtank.  Or a PS Audio.  Or a Pure Power.  Funny how so many people have owned and sold that gear because they like the wall better.  And yet audio forum members who may or may not have any relevant understanding of electrical components are going to cobble together some parts and outclass a full scale corporation. Not saying it cant be done.  Just saying, real business are trying and partially succeeding.  

Due to my summer home location I am off the grid so I am using a fairly substantial solar installation ie six 425 watt panels four 465 AGM amp hr batteries a 3000 watt pure sine wave inverter the system has no issues powering an Audis Fortissimo integrated tube amp a Sugden a21se signature pure class A amp and Goldnote PA10 mono blocks and DS 10 pre/dac/streamer I also have an AYON S10 MK ll signature pre/dac/streamer I have had nothing but pure listening pleasure on my Audiovector R6 Arette speakers I just purchased a Nordost QB8 MK 3 power bar for fine tuning 

It’s been awhile so I feel like I should chime in with my findings. What I’ve found is that I get better sound with the following setup rather than going direct to a 12V battery with my equipment that can take 12V DC. It seems counterintuitive because it’s adding so many extra components compared to just a battery but I swear it sounds better. 

For example, here is how I have powered my preamp which needs 12V DC to run:

12V DC 75 Ah sealed AGM battery -> 600 watt, 120V AC, pure sine wave power inverter -> 12V DC extra low noise power supply -> preamp.

It know it seems funny to start with 12V DC and end up with 12V DC but it just sounds better than plugging the 12V DC battery directly into the preamp. If you think about it, it’s not all that different than a PS Audio Power Plant, and it seems to avoid many of the problems with direct battery powered systems. 

I called Giandel.  Someone said their inverter was light years ahead of other.  They told me their inverter was not the best for audio.  2nd inverter manufacturer that told me as much.   They do get feedback from people trying this stuff. 

I talked with a guy who supplies Equitech with inverters for homes with power sags.  They use a large UPS.  About a $30k unit.  I don't get it.  Its full of deep cycle battery.

Every direct to the wall vs a battery system such as I noted above, the wall is always better on amps.  If you add a Torus, the wall is way better.

The front end is the hmmm, well, maybe part.  But then again, a AQ5000 gives a black background if thats what you want.

  A Denali is also quiet with some snap.  

A Torus is quiet with more life and air.  Pretty similar to a Denali.  Just the transformer does amps very well. 

I want to try an inverter and battery.  But I want the unit capable of powering a class A 150 watt amp.  Or tube amp with a ststic draw of say 6 amps with peakes.  As well as a preamp, phono pre, DAC, server, switch, TT motors.  It has to power a stereo.  Not a walkman or headphone rig.  And it should be compared against wall power that is 4 didicated 10 awg circuits not longer than 40 feet.   The electrical panel should be refurbished with new breakers and the grounding polished and reading 5 ohms or less.

Yesterday I was assessing a home.  The wall had 3.2%thd on the 3,5,7.  When the Denali was plugged in, rhe wall jumped to above 13.5% thd on the 3rd and up quite a way.  Massive backfeed noise into the main line.  The load side of the Denali had the exact same 3.2 or so thd in the 3rd and 5th.  More on the 5th.  

I bet you would get very similar readings on the load of an inverter.  A true isolated battery system would not pollute the mains.  That is a benefit.