This is an amazing piece from the mid 80's that allowed you to add reverb or echo to your system to give a more realistic "live" feel. I've used this in a stereo setup as well as a studio piece for the reverb. Sounds great! What a cool thing to add to your set up.
These are super rare and go for a ton on sites like Reverb (one listed right now for $2k). I'm looking for a local sale before I list it there, this is the deal of the century.
Here's what the internet has to say about it:
Description
What really gives music that you-are-there realism is the amount of echo or reverb you hear in the sound.
A larger amount of echo can make you feel like you're sitting in a big hall or cathedral - smaller amounts create a discotheque like environment.
Add echo to the sound from your videos, and you've got your own movie house; right in the home.
The Sansui RA-1000 gives all the concert halt realism you need, plus more.
You can make a solo artist sound like a duo, mix voice or guitar with the program of your choice, and record the mix on a connected tape deck, all with echo.
Because we use an electronic BBD reverb unit, reverb is natural and noise extremely low.
For enhanced sense of realism (or just for fun), there's nothing like the Sansui RA-1000.
Specifications
Frequency response: 10Hz to 80kHz (line)
Total harmonic distortion: 0.025%
Input sensitivity: 0.5mV (mic), 150mV (line)
Output voltage: 150mV
Signal to noise ratio: 80dB (mic), 95dB (line)
Reverberation time: 0 to 4.5s (echo), 30 to 200ms (duet)