Home Propeller Head Plaza

Technical and scientific discussion of amps, cables and other topics.

[ Follow Ups ] Thread: [ Display  All  Email ] [ Propeller Head Plaza ]
[ Alert Moderator ]

Re: What happens when there is no negative feedback, A subjective perspective.

Your measurements for this Panasonic amp don't seem terribly different than what I have seen with other Class D amps with or without negative feedback (I believe nearly all of them use negative feedback but if you say this one doesn't then I guess it doesn't). For example:

http://stereophile.com/solidpoweramps/406halcro/index4.html
http://stereophile.com/solidpoweramps/805cia/index4.html
http://stereophile.com/solidpoweramps/405yamaha/index4.html
http://stereophile.com/solidpoweramps/729/index8.html
http://stereophile.com/solidpoweramps/729/index9.html
http://stereophile.com/solidpoweramps/442/index5.html
http://stereophile.com/solidpoweramps/442/index6.html
http://stereophile.com/integratedamps/106ps/index4.html
http://stereophile.com/integratedamps/253/index6.html
http://stereophile.com/integratedamps/253/index7.html


As you can see, they all act a bit wonky and most have tons of out-of-band noise that is riding on JA's squarewave measurements.

FWIW, I have big problems with how nearly all Class D amps sound, regardless of implementation. The expensive Sharp is the only one I have heard that really performed well sonically. I think it has a lot to do with the HF noise of the amps and their apparent large increase in distortion at HF. I would not be surprised also if the problems with grounding is an issue due to all the RFI.

However; to blame the sonics on the amp being a non-global feedback design is just silly when 1st it is a cheap as hell product and 2nd even these rather expensive items I posted here all have similar if not identical problems with noise. I find it funny in many of the links JA makes it a point of saying he hates to measure Class D amps because it is hard to tell what is distortion and what is noise.

Picked the wrong amp to try to prove whatever dubious point you were trying to make. Why are you protecting the cd player manufacturer? You didn't spare Panasonic.

This post is made possible by the generous support of people like you and our sponsors:
  Parts Connexion  

Follow Ups Full Thread
Follow Ups
You can not post to an archived thread.

[ Top Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]
[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]