ICE amps need cooling?

Muralman1 - I still don't understand why you keep calling switching power supplies "digital". As for them being suitable only for mass market and not for the audio (your original statement) your Henry Ho (H2O) released two amps with Icepower modules with built-in switching power supplies M250S and M500S. Alleluja!!!

The only other circuitry in my Rowland Icepower amp is tiny input board with differential amp THAT1200. If there are any modds to original Icepower they are probably done at factory level (modds void B&O warranty) and reflect desired "house sound".

Eldartford - Rowland was widely using batteries in preamps and wrote a lot of FAQ about it. Now he switched to SMPS (Capri). If there is any switching noise it would not be able to hide well since Capri's bandwidth is 350kHz.

Henry Ho has had ASP amps out for years now. They are a cheap offering for people who want the class D sound but can't afford the flagship.

His Fire preamp, a HOT class A design, is pristinely clear and dynamic. I know if Henry thought using an ASP module to create a preamp a good idea, then he would not have gone to the trouble designing a preamp from the ground up.

Most recent JRDG amps use SMPS, including the 312 stereo, which is designed around the ASP1000 module. While 300 series amps have substantive cast Aluminum cooling fins, I suspect these may be more cosmetic than anything else, as the external temp of 312 never grows much above look warm. It is worth pointing out that at approx $16K, the 312's price point is not exactly consumer grade, yet Jeff Rowland determined that an SMPS front loaded by a PFC unit would yield a musical performance superior to that of the previous 302 model, which used a linear power supply instead. . . and I do agree with him. Issue 188 of TAS should just be reaching the newsstands. . . it contains a sidebar that I have written on the JRDG 312 amp--part of my review article on Vienna Mahler speakers.

On the subject of battery PS, JRDG has implemented a battery PS on its new Criterion linestage flagship. . . which hopefully will ship before year end. G.

Batteries are potentially messy and some can emit either fumes or hydrogen gas. Enough battery power for a pair of BelCanto 1kw monoblocs would take up a bunch of space, too.
Than you gotta deal with the charger and battery maintenance.
You would ALWAYS run the batteries down at the WRONG time. that is one of the RULES.
But, on the other hand, I just received an IR amplifier module, stereo class 'd' which I intend to power with batteries. Amp takes +-50v which is good for 4x12 on each rail. I'll deal with the charging and other issues later. The attraction of zero ripple and huge, near-instant current is very seductive.
Battery chemistries other than lead-acid / gel cell is available in Lithium/Lithium polymer and varios Nickel Metal Hydride cells along with the old standby, NiCad. I don't know the half cell voltage of these, but some require smart chargers (the charger, not YOU) and certain other usage restrictions.
For DIY where there are few restrictions, it's worth an experiment, but in the commercial market, batteries may be too much.
Also, a note on the numbers:: IF you run at what works out to be high power levels, say 4 amp total average draw, on each 'rail', you may need considerable battery capacity. A set of batteries in series will have the amp hour capacity of 1 battery.....1 12v battery of 50amp/hours will still have 50amp hours when 4 are in series....but have 4X the WATT hours.(P=IE) But, measuring in amp hours, my made-up 4amp draw, per rail, will use up each rails batteries in 10 hours of listening, with a small reserve.
Clearly, in this instance you couldn't run a Class 'A' system, but rather the numbers prefer Class 'D'.....