On Wed, 22 Mar 2017 04:08:20 -0700 (PDT), "
wrote:

Koss is doing just fine. Their electronics division is gone. Historically, many
transducer companies, starting with KLH, AR, Advent, ADS

OK, now I know that.... I'm sure this receiver was just rebranded by
Koss. If I could find out who made the thing, I could probably find a
schematic for it. But how to find that out seems near impossible.

Since you mentioined KLH, the speakers I am using are KLH brand. Great
sounding for their small size.