200W / Ch Class D vs. 5W / Ch Class A Power Amps

For the past few days I’ve been playing with a home brew IRS2092 based 200W / Ch Class D and a Nelson Pass 5W / Ch Mosfet Class A clone power amp. Apparently this is completely faithful to the original cct.

Using my Quad 34 pre and my 90dB Heco Celan 300 speakers in a tiny room, near field listening.

Whilst by no means scientific (feel free to rip me apart for my lack of technical knowledge), the results amazed / disappointed me.

The Class D Amp absolutely hosed the Class A in every single area, every type of music. Not even close, not in the same universe.

Its quite possible that the pre is a mismatch to the Class A amp, I suppose, or that 5W isn’t enough for 90 dB speakers in a cupboard but what a disappointment.


Which Pass amp? is it the amp camp amp?

If your ears say it’s better,then it’s better


Your subjective opinion not coinciding with that of other people really isn’t remarkable. Not having a dig at you, it just isn’t.

That said, 5W is pretty flea-powered for the Celans…


Those are total shit.


True dat.

1 Like

Drink stronger alcohol.

1 Like

Down with this sort of thing. A common sense and reasonable polite reply is not the AA way. :face_with_raised_eyebrow:
You are right though.

1 Like

Pass F5 or Aleph 30 etc are worth a go.

I’ll go for this explanation

1 Like

ACA distortion:


:sob: :face_vomiting:


Eek, that is not good.


The Class D also hosed my Snook modded 405-2, my Rega Brio and a Roksan K2 that I borrowed. Was hoping that Class A (maybe this one wasn’t a good choice) would be better.

Tbh, I’m beginning to think that I’ll not better the Class D for do-able money.

THD not the full story. What is the harmonic distribution proto-Serge?

Sh1t ! No wonder, then.

My Aleph 30 sounds great.

No it’s not, 3rd order comes in at about 2w, and there is a good chance he is clipping a lot too at 5w which never sounds good.

Don’t know that clipping came into play. It was plenty loud enough at well less than half volume.

The post potion of a volume dial really means nothing, it will have been clipping.