Vacuum Tube Optical Compressor Module

The RMSMC5 Valvop from Roll Music Systems.

A real, transformer-coupled tube optical compressor in the convenient package you never thought possible.
At long last, all the warm sweet satisfaction of an optical compressor with a real transformer-coupled, high-voltage vacuum tube audio path in the convenient and cost-effective 500-series modular format.
You love the sound of the RMS5A7 Tubule tube mike preamp module, and now you can enjoy that same sonic bliss in a line-level compressor and the same form factor. The compression is all optical for a smooth compression that's ideal for both vocals and electric bass. (But don't let us stop you there!) The audio path uses the same all-tube amplifier circuit found in the Tubule.

There are only 11 gray panel versions that were made and they have a slightly different circuit than the blue panel versions.

https://www.rollmusic.com/valvop.php

This Module is currently available.