Schiit make a standalone tone control IIRC.
At the peak of the cost cutting in the 80s, tone controls were put in the NFB loop of the power amp stages for many of the big brands to keep costs down at the low end. Not my idea of superior design, but it worked. Basically someone said, why build a standalone Baxandall feedback active tone control up front of the power stage when we already have the guts of of it already?
This is actually a PM-640 HK integrated from about 1983/4. An otherwise very nice amplifier.
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