Class D is just Dandy!


I thought it was time we had a pro- Class D thread. There's plenty of threads about comparisons, or detractors of Class D.

That's fine, you don't have to like Class D amps, and if you don't please go participate on one of those threads.

For those of us who are very happy and excited about having musical, capable amps that we can afford to keep on 24/7 and don't require large spaces to put them in, this thread is for you.

Please share your experiences with class D amps!
erik_squires
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
As I mentioned before I have a Primare I32 and a Topping TP30 mk2 that I connect to the tape out to drive a Stax headphone system. I have a pair of old BA T-830s connected to the Stax adaptor for the hell of it. Sometimes, when I want the best sound from the Stax, I connect them directly to the Primare, which I did tonight.
After a while I reconnected my 'big' speakers, Canton Ergos, to the Primare and popped I Robot SACD into the BDP-95. It sounded really good. I got to a loud passage and turned the volume down with the remote. Still too loud, so I turned it down some more. And more, and..
I finally put my glasses on and saw that the Primare was down to 0 volume and I'd left the TP30 on. I had been listening to the BA T-830s being driven by a 10 Watt (generous) class T amp the size of a sandwich in a 38'x28' room with the volume less than half way up and it was still too loud!