The Truth Pre Amp
It has an input impedance too high to measure, output impedance is a couple
ohms, bandwidth is to 60Mhz, slew rate is a couple hundred V/microsecond.
There are no capacitors or resistors in the signal path. There is no potentiometer
in the signal path.
It uses photo cells to control the volume. It does not use optocouplers.
It is an "active" device and suffers none of the "problems" that "passive
volume control/pre amps" have. It can drive long (30 feet) cables with ease.
I've had parts of this circuit run for >10 years without failure.
As far as I know there is nothing like it available for any price.....I
could be wrong but I doubt it. I looked "pretty hard and long".
The price in a painted Aluminum enclosure is $975 shipping included.
Extra inputs are 40 dollars. Remote adds 250 dollars.
Please call me with any questions........also, there are a couple threads
on my forum which may be of interest.