Optimus STA-3500 mod question

[Leslie Horn]

This is a good mid-grade tuner/amp,
but I have two complaints:

1)
I don't like the tone stack, and I wish to modify it,
but I can't seem to find a Fotofact or mfg man on
this unit. The clowns at Radio Shack offered me
a "user's manual". How droll.

2)
There is no preamp to power amp breakout,
else, I'd just pull the jumpers, and slap in a
parametric equalizer.


This is a VERY GOOD bipolar tuner/amp, save the
black-on-black lettering (making it impossible
to see under low ambient light), and the pitiful
tone stack.

About the stack:
I want to convert it to a James stack, but
I quit reverse engineering, over 20 years ago.
I rev'eng'd as a hobby - but not out of necessity.
However, I'm glad I did, because I learned a lot.
But to bin this unit? WHY? It still works, and
It works well. It sounds good, with the bass and
treble set flat (or at least to the center indent).

I have an older unit, too, that does have
back-panel breakouts for preamp out / amp in.
Maybe I'll dust it off, and see if it works.

I said all that, in order to ask this:
If anyone has service literature and/or a schematic
or Fotofact on this unit, please post back here, and
feel free to email me. This model is discontinued,
and I want to save it from the landfill. Vintage audio
equipment doesn't belong there. The quality
(or lack thereof) of consumer electronics today only
underlines my point.