Bought mine used around 1985
Not sure about the model #..she's a two channel beast. Loved it to death until all switches and pots got dirty.
Now is doing listen mic (PZM) compression duty

Some clients go apes about the drums through that chain and decide to print it !
Great box..IMO.
I've used it mostly for low end and percussive stuff. It had this character..tightly packed, firm audio. By using the switched release constants, you could almost "tune" the source into the mix.
groove on