I saw a schematic for the amplifier years ago. They key was what appeared to
be linear optoisolators in the feedback circuitry.
I was going to build it up, but it looked as if the designer put quite a bit
of work into the circuit design, so I took a pass on it.
I purged the details from my hard drive a few years back.

Pete

"Nocturnal1" wrote in message
...
I've built several loops and they are all similar as you say, but the KIWA
loop is quite a different animal! I've have mild success with what I've
done
so far in my efforts to duplicate one, but I cannot seem to find much on
the
regenerative loop and circuitry contained within it.

~Tom in Mn