But seriously, that model should compress wonderfully, that is the original SC2. There is certainly a problem.
With that model the most likely cause is faulty transistors in the compression drive circuit; there are 4 transistors and it is worthwhile to change them all.
If you need the circuit information for this model I can email it to you.
If you would like me to repair it and set it up correctly, then drop me an email at
The additional output gain control should not affect the compression in any way.