If the meter is showing GR then the sidechain is operating correctly and the problem is either the gain cell or one of the driver LEDs.
The chances of a gain cell failing are very small…. the most likely cause is the failure of one of the LEDs.
Note for others…. the compression circuit on the VC2 is not the same as on the SC2 compressors where a fairly common fault is failure of one of the LED driver transistors.
If you would like me to look at it and fix the problem (and check the gain and linearity of the valve circuit as well) My offer on old JoeMeek gear of my design still stands; the cost is now £30 plus the cost of returning the unit. That charge holds for all ‘fixes’ unless an expensive component like a meter or a transformer is required.
If you would like the circuit diagram of the VC2, please email me separately at