NCore ICEpower Other Class D with Electrostatics

Joined 2005
Paid Member
I have tried quite a few Class D amps on my Electrostatics over the past few years - Quad ESL-63, Acoustat 2+2, 1+1, Model 3, Spectra 22, and Spectra 11, Sanders Model 10C, Martin Logan CLS IIz (I may be forgetting a couple more).

Only the ICEPower 1000ASP and 500ASP (have not yet tried the 250ASP) had no issues. Although I do remember a night where my Acoustat 2+2 at fairly high levels caused one of my 1000ASP monoblocks to shut down, but after power cycling and reducing volume, it was fine again...

The Hypex UCD400Hxr and NC400 both fluttered and shut down after about 12 - 15 minutes on the Acoustats and CLS and CLSIIz at normal volume. Also tried the Emerald Physics 100.2SE (TDA8954 Class D amp) and had similar issues. All were power cycled and were fine again...

Surprisingly, the ESL-63 were ok with all amps but the Emerald Physics, but I did not push it.

Its understood that Class D amps have issues with the Capacitive loads an Electrostatic Speaker presents to it...

BTW - never had a Class A / AB amp shutdown on them...

So, has anyone successfully driven ESL speakers with NCore amps, UCD400Hxr, or other Class D? Like I said, the ESL-63 seems to be an easier load than the nasty Acoustat 1+1 and CLS...

None of these amps had any issues driving my Magnepan 3.5r to high-ish volume...
Last edited:
Good Afternoon, john65b:

Have a used classDaudio SDS-250(254?) that I've use(d) with a pair of 1+1s without issues but in a small room approx. 10.5ftx11ft. (Yeah, I know almost square) with bass traps in the corners and smaller middle traps in the middle of the front and back walls. Also have a couple of free standing Room Tune diffusers/absorbers just off to the sides and in front of the 1+1s. The wall behind the 1+1s have a curtain in front of the drywall. Only thing is I don't push it beyond what's sensible and what my hearing/ears can tolerate (e.g., not run out of the room loud! - lol).

Have recently picked up a used Digital Amplifier Company 2-Cherry that also have had no issues with driving them to the same levels as noted above.

Haven't tried these two amps with a pair of Model 3s yet (as the threes are an easier load to drive) and which I don't think/believe there would be issues with doing so.


I used my PSC2.400 hypex amp on my Solosounds.

No problems at all. The amps could run into the occassional clip (snaredrums etc.) but no shutdowns.

The panels where crossed over at 500hz.

The old amps died. So I replaced the amp with the Ncore based Hypex FA503 (2 500W, 1 100W channel).

This one has a much larger power supply and runs a higher supply rail voltage, and now, even on rather low listening volumes, the occasional sparking panel.
I'm not really amazed, but of course not amused...