WEAK-AM

I’m running a classical music format with my SSTRAN. Now that it’s been up and running for awhile, I’ve noticed that on softer passages, there’s kind of a “gating”effect on the audio. Soft sounds are greatly attenuated below a certain point, above which they increase rapidly in volume. I’ve played with the gain and compression settings, but to no avail. I doubt if anyone else out there is running classical music on AM, but I wonder if anyone has noticed this effect at all, and what you think might be the cause? I haven’t reverse-engineered the compressor circuit to see if that is a side effect of the circuit design.