Class D is just Dandy!

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

Using feedback to reduce distortion isn't a free lunch though, or is it?

From what is understood for years by the guru's of amp design, is that any amp should be designed for as little distortion, low output impedance ect., as possible without the use of feedback. Then to use just a little feedback if necessary to clean it up if need be.

Cheers George 

feed-forward loop

Feed forward was used in the old days, and it was resurrected again by Rogue in their M120 and I believe in their M150/180's.

Cheers George