Class D is just Dandy!

     Very nice to see almarg and atmasphere team-up, step up and use their knowledge/experience to solve islandmandan's noise problem. Nice job guys!

     What I've consistently noticed from listening to good class D amps in my system, from my initial Class D Audio SDS-440-CS stereo amp to my Emerald Physics 100.2 to my most recently purchased D-Sonic M-600 mono-block amps, is their exceptional quietness;  music seems to emerge with more impact due to the dead quiet background.
     I believe this silent quality is also a primary contributor to the other obvious characteristic of good class D amps: a very detailed presentation..

      I'm almost certain these class D attributes will now be very evident to  islandman  now that his amps are operating in their typically silent manner.

Enjoy,
 Tim

My goal was a little desktop integrated or pre/amp combo.

After hemming and hawing and fretting I purchased an NAD D 3020. My local dealer had one $100 off.

I ruled out all of the Parasound Z series just because they are too big. at 9" wide they wouldn't fit on top of a speaker, like I need.

Plenty of digital and a couple of analog inputs make the input selection pretty good. There is also a bass boost which is perfect for my little desktop speakers.

So far so good. The one negative is really the volume display is hokey as hell, and it takes a lot of turns to adjust it.

The display has a series of numbers: -20, 40, -60, -80 and -100. As you turn the volume down the numbers dim, or go off. The physically larger sibling the 7050 has a graphical display with direct volume readings in dB. It was only a little more expensive, but seemed to lack analog inputs and was twice the physical size.

They call this a hybrid digital, but I could not find much information on what makes it a hybrid.

My only source right now is the PC, via analog, but I'm always careful to get motherboards with S/PDIF outputs so I'll try that eventually.

Oversimplifying, 'Hybrid' means that the digital source is upsampled to the scan frequency of the amp.

Found a partial answer:

NAD calls the D 3020 a "hybrid digital amplifier," by which they mean that not all of its circuitry is in the digital domain. The D 3020 combines a Cirrus Logic DAC (eight channels mixed down to two) with a class-D output stage designed by Hypex, of the Netherlands. According to NAD, the output stages aren’t fazed by low-impedance speakers.

Hard to interpret exactly which part is which though, especially since Bruno Putzeys bristles if you call his amps "digital." Still, I will guess this is at least not a Hybrid a'la nuForce or Yamaha EEEngine, but something else.

https://www.stereophile.com/content/nad-d-3020-integrated-amplifier-sam-tellig#1FLoXpsCMuhoTAk1.99

NAD D 3020 sound quality

This is a good performer, a huge step up fro my $20 Lepai 10W/ch digital amplifier. It is extremely quiet and smooth, without grain or harshness but also without warmth.

The bass boost is a huge help as my desktop speakers are pretty lean sounding. My previous experience with NAD DACs was pretty negative, but this is pretty easy to listen to. Tons of air and detail.

But zero warmth. In this sense it kind of goes towards the Emotiva/Asian processor sound qualities. Kind-of, but not nearly as bad as the worst of them. There's just no sweetness or warmth at all in the sound quality. "Stark" may be a good way to describe it, but without the thin/limited range effects I get from the worst of the Asian designs.

Reminds me a lot of the 1990's digital sound, if you took that and cleaned it up a lot.

So, killer, top of the pack? No. Quite enjoyable, space saving and feature packed is how I would put it.

Best,


Erik