I am adding some SSL-influenced mix bus compressors to my test pile. I just wrapped a Stam SA4000-5 MK2 and was surprised with how high the IMD and THD were. If anyone is willing to loan me their CP4500, it will take me about a week to test and I can cover shipping, assuming you are in the US. I’ve tested all the DIY units I’ve built but this one is not in the cards for a while. I will provide you with a copy of the test report, including IMD, THD and harmonic response (strength of each harmonic), noise floor (using linear and switched mode PSUs), EIN, and transfer functions for bypass and max gain. I also do tests with 6 dB, 12 dB, and 18 dB of gain reduction.

These are steady state tests only, not an attempt to quantify transient response or sound, just the common benchmarks.

I ended up finding one locally, will try to post results for others to see.

Any conclusion?

Yes, summary results posted here:
https://reverb.com/item/75881760-sou...ntent=75881760

Can you elaborate? And also what is your use for the compressor? And what did you bring instead?

Oh I see you wrote a text there. Good to know since I have one and I thought of upgrading