Class D at low volume

Tim, GNFB serves the same role in class D as it does in class AB - reduces distortions, widens bandwidth, reduces output impedance. It is not necessary for operation in general but particular circuit can be designed to depend on it.

Since even shallow 20dB of GNFB will improve everything tenfold it is very tempting to use it. It can be done without negative effect if certain rules are obeyed but then GNFB will be shallow. Designer has to start with good design and quality components to start with and not to fix everything with GNFB.

As for new Benchmark amp - it is class AB with SMPS supply.
http://www.enjoythemusic.com/magazine/equipment/1214/Benchmark_Media_AHB2_Stereo_Power_Amplifier_Review.htm

Pavpet, yes TIM distortion can be fatiguing. It is basically an overshoot, in time domain, of the rapidly changing signal. It won't show with any THD or IMD measuring. In freqeuncy domain it translates to very audible odd order harmonics that our hearing is sensitive to. It makes sound bright. In extreme cases (perhaps some SS amps in 70s) overshoot was so big that it could choke output transistors that remained choked for a while (charge trapped at the junction) creating short gaps in music. These gaps were not audible, since our brain compensates for that, but made listeners very tired.

lots of great thought in this forum discussing class d amplifiers, being an audiophile since 1970 , and owning very expensive gear , its nice to purchase a product at a very very resonable price , and make magic , the wyetech ruby monoblocks list for approx $25000, plus ive installed 1942 rca 211 radiotron tubes , ( took out stock tubes as well as input tubes)AT an additional $3300 , plus upgraded power cords , but thats the audiophile journey , this i know , but now and then its nice to get a breath of fresh air ,without getting a second mortgage. guys thanks for all your input very much appreciated

Tim: thanks for getting off topic. This thread is educational for me and hopefully for many others as well.

Thanks for your comments folks! Please keep the discussion going.

Serge,

I was looking at your initial thread posting again and you stated you're considering Lab.gruppen, Powersoft, XTL and others. These are pro amps used for large venues and not intended for home audio.

I apologize that I didn't read your original post closely enough. However, all of my replies, as well as most replies from others, were based on the assumption you were looking for an amp for your home audio system.

I've never used pro amps and have no useful knowledge about them. The info and impressions about class D amps was based solely on my experiences and knowledge of home audio class D amps and may not be applicable to the pro audio class D amps you mentioned.

I think you need to clarify exactly what purpose these amps are intended for.

Audiogon is a site devoted to home audio, not pro audio environments that are used in clubs, concert halls and auditoriums.

If you are interested in pro audio amps, I would suggest posting your question on a forum devoted to such.

All of my replies, and I think most if not all of the other replies on this thread, were given from the perspective of home audio and therefore should be disregarded.

Sorry for the confusion,
Tim

When I want a nice listening session, the gear is warmed up already but not my ears.
I like to listen at a lower level for a little while as my ears get acclimated (warmed up too I suppose :) )

I`ve been noticing that I`m listening much longer at the lower level before I actually come to realize it...and the remote is sitting right next to me ! This Class D Audio 470 sounds great across the board no matter what volume and that`s a first for me !!