I never understood why the C2 was not a huge success, I can only think that is because it is too small!! The circuitry was absolutely the best at the time, it was an early implementation of M/S compression (sum and difference) where the stereo image remains absolutely stable under heavy compression.
No, there are no transformers, just some very clever input and output circuitry (although I say it myself).
I would put the C2 up against any compressor in the world for good musical compression….. I have one myself and it’s really good!