KRA Vari-Mu Compressor

I built this compressor in the chassis of an Akai M7 monoblock, but I have completely re-purposed it. This circuit is based on the Federal AM-864/U. Since the Federal uses octal tubes and my chassis has 9 and 7 pin tube sockets, I had to select appropriate substitutions. The tube lineup is: 6eh7, 6eh7, 6at6, 12au7, with a 6x4 tube rectifier. The compressor has input and output volume controls (big knobs in the middle) as well as threshold, ratio, attack, and release (little knobs along the left). The VU meter can monitor the output or the gain reduction. The VU can also be switched out of the circuit.

I have plans for a future revision that incorporates switchable input and output pads as well as a bypass switch for the compressor.

Let me know what y’all think!