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Peter Wieck[_2_] Peter Wieck[_2_] is offline
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Default High End Class D

John:

I see that, once again, you are nibbling around the edges of the "Brute Force Amp" concept. I kinda-sorta figured you would get there eventually. And, coincidentally, you missed out on a Harman-Kardon Citation 19 that I tripped over at a yard sale - my son-in-law laid claim to it the moment he saw it on the bench.

But, getting to your question directly: If you choose to move to Class D amplification do go for the most recent designs and do pay attention to how the signal is filtered to the speakers. Put as simply as possible: "Good Audio Quality" class D was only a concept as recently as 4 years ago. Today, distortions (all components) of less than 0.05% are routine. A few years ago, damping in Class D was very nearly non-existent. Today, it is approximately that of a 30-50 watt tube amp. Low, but definitely there.

A few things:
a) Class D amps do not like being run at/near rated output for long periods.. They do not 'blow up' but they do get quite warm.
b) Based on the nature of sound and the decibel scale, if you are going to go to Class D, go BIG - Given that the next step after a 20 watt amp is a 200 watt amp, start there. Really. Do not try to gang them up, start with the highest power module you can afford and work from there (The 686 in Neurochrome, or any of several other brands:

https://www.parts-express.com/icepow...-500w--326-200

https://www.diyclassd.com/diy-amplifier-modules/

https://www.dhgate.com/wholesale/cla...rs+module.html

As you can see, prices are all over the place and largely depend on how user-friendly and/or complete the various parts will be on arrival. But the overall audio quality will be largely indistinguishable **!IF!** you purchase an audio-purposed module initially vs. something for sound reinforcement.

My 'audio-snob' neighbor down the block built a Class D amp recently in a COVID-related fit of boredom to compare to his 300B-based flea-powered SET tube amp - he used the 150-watt mono modules, with separate power-supplies. I am not sure he is going back to tubes.

Repeat: GO BIG, or not at all - no need for extremes (1,100 watts, for example), but getting those transients is worth something.

Peter Wieck
Melrose Park, PA