OP
Thanks for telling us about it.
I use a Chase Remote Line Controller RLC-1, here’s one:
No moving parts, all done somehow in a single Philips chip, here’s the innards.
It has no face controls, you must have the remote control.
4 line in; 2 identical line out, remote volume, balance, mute, tone controls, and IF you lower the volume a lot, automatic and progressive bass boost.
Virtually no noise, no one can tell if it is in or out. I know, ’straight wire with gain’, I have taken it out, put it back in so many times, I cannot detect anything except it’s benefits, remote balance it’s favorite feature of mine!
I only use 1 in, from my preamp, 1 out to my amp.
It has an accessory power outlet (some early or later variations don’t) which is useful for switched power to something.

