I think you're speaking of the IcePower amps used by companies like Jeff Rowland Design Group and Belcanto. IcePower was used in a Bang & Olofsen self-powered speaker, but it went through years of development before it was licensed to other users.
It's an off-shoot of Class D (it IS NOT digital, as there's no analog-to-digital or DAC).
As you might suspect, high end designers don't just take an IcePower unit and stuff it into their own case then mark it up a bunch for a nice profit. There's a lot of design work going to such things as power management, filtering, RFI and EFI protection, etc.
I know more about Rowland because I own a Continuum 500 integrated amplifier with phono section. Part of how Rowland achieves ultra-quiet operation is with Power Factor Correction which converts ANY AC line to 385V. After listening at 85dB average I can turn off the source, put my ear to the tweeter and not hear a thing. It takes another 10dB before I start hearing anything, partly because any chance for 60-cycle hum has been removed.
As your read around the forums you'll see a lot of negative energy about IcePower or Class D. I think that's way out of date. In the best incarnations it can be incredibly transparent, detailed and stress free.
Listen for yourself. I don't know your wyred4sound amp, so I cannot comment on it specifically. Since there's a lot of variance in application of IcePower, you'll need to listen with your own speakers. If you can hear Rowland or BelCanto, do.
Dave
