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"switching" noises from SS Class-AB amps

Lately, I have been thinking that solid-state Class-AB amps can generate "switching" noises too. It has been known that Class-D amps generate switching noises, and noises reduction can improve Class-D amps. However, the output stage of a Class-AB amp also switches between on and off states.

Another example is the diodes used in the rectification circuits. It has been shown that using soft recovery diodes like FREDs can reduce the noises from the rectification circuits.

I am a big fan of Bybee purifiers. Some people, including myself, have used Bybee purifiers after the diodes or regulators with good results. Now, I am thinking to put Bybees between the output bipolar Collector legs and V++ or V--.

I have a hybrid power amp with tube gain stage and SS driver and output stages. I really like its bass and mid-range. However, its treble is not as "pure" as my KT88 amp. Additionally, I have a much more relaxed feeling after listening to the KT88 amp for hours. No stress at all!

Has anyone tried to reduce the noises from Class-AB output stage before?
vett93
sidssp
1,077 posts
 
Vett93, if you don't know what you are doing, don't modify amp. I don't know much about those Bybee filters but you could throw the two sides of the output transistors out of balance and cause significant DC current to show up at the output terminals.

For safety sake, please leave mod to engineers.
vett93 OP
205 posts
 
Thanks Sidssp. Your concern is appreciated. I'll put one on each side of the output transistors. I am working with the designer of my amp. He thinks it is okay too.

BTW, I am an engineer myself, an EE actually. But that does not mean I am safe. :-)
wwshull
157 posts
 
i have no problem with switching noises with my amps they run most of the time in a but when you get loud they will switch to b.
sidssp
1,077 posts
 
Vett93, In that case, good luck to your quest. And please let us know how it turns out.
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