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
Post removed 
Thanks for starting the thread. Two of my three home setups are now Class D, the third being a much-loved Marantz 2230. My listening room is the newest, a Rogue Sphinx driving Magnepan .7s, with a Musical Fidelity V90 DAC, Marantz 5004 CD player and Pro-Ject Debut Carbon with Ortofon 2M Red. I just think it all plays together very nicely. Auditioning the Sphinx I also listened to an NAD C368, but thought it had just a bit more sibilance and an amplified character with solo voice, which I'll assume is the effect of the Sphinx's tube preamp section. I listen to mostly classical, jazz and acoustic. 

My other Class D is -- please don't laugh -- a Teac A-H01 driving Magnepan MMGWs. It's in the living room, and I wanted to keep the music system as small as possible. When I was shopping a few years ago for this setup, the Teac was one of the few small integrated amps that had a good mix of digital and analog inputs and a subwoofer out. It's got ICE amp modules and a Burr-Brown DAC (I didn't need a phono, which it lacks), so I was willing to give it a go for $330. It puts 43 watts into 4 ohms, which isn't supposed to be enough for Maggies, but they sound great. They seem to love being spread far apart - about 15 feet on opposite walls. They don't go very loud, but they don't need to in this location.

Here's the deal: Like I'm sure a lot of people here, I listen to a lot of live music, meaning symphonic or chamber or opera/musical -- unamplified sound, in other words.As far as I'm concerned, if an amp makes a violin sound like a live violin, and a piano sound like a live piano, etc., it's doing it's job - Class A, A/B, D or whatever. That's what both these Class D amps do, and what the Marantz still does as well. I first heard the MMGWs at a friend's home with a very nice, all-tube amp/pre combo with quite a bit more juice than the Teac. But I've never been disappointed in how they sound with my setup.

Cheers.


Nord One SE  uses the same components as the Nord One UP,  Hypex NCore NC500, twin SMPS1200A700 PSU’s in our beautiful sleek Japanese Mono Block or Stereo Chassis.  SE comes with Nord Class A Discrete Input Buffer board with choice of discrete Op Amps, Sparkos SS3602 or Sonic Imagery 994 +£30 and Sparkos discrete Voltage Regulators. Choice of Dual Mono Stereo or Mono Block chassis
these are what i use in the UK driving my soundlabs they sound amazing prices start around  600gbp up to 1700gbp for the top reference monos which are what i use 
i have heard nothing like them , very detailed , dynamic , powerful but so musical and natural sounding , i have tried half a dozen class D before these , no amp i have heard betters the nord 
they ship all over the world 
Linear amplifier distortion can be reduced by feedback, something digital amps may use in buckets.
Using feedback to reduce distortion isn't a free lunch though, or is it? 
It may not be, but it works totally differently.

In a digital amp the feedback affects the width of the "on" period.

First, I’m not sure that anyone has proven in a linear amplifier why moderate feedback is a bad thing. Second, in class D it is a couple of stages away from the output signal, so whatever arguments you might have made for a linear amp’s feedback I don’t know that they would work at all.

As I understand it, Technics is using more of a feed-forward loop. They analyze the errors with the output stage, and then digitally correct it ahead of time, before the actual power amplifier stage. Talk about a huge amount of processing and signal meddling though. :)

The Technics approach is VERY similar to digital EQ and phase correction if you were to limit the correction to purely electrical, it is identical in theory.

If you go that far, might as well include the acoustic output of the speakers as well and finish the job. :)



Best,

E