Bit of a strange one….. there`s nothing in a VC1 that can cause a whine except maybe something wrong in the enhancer circuit.
In any case it`s not something that could be fixed locally. If it`s a really treasured mic amp, then please send it back to me at the Sound House and I will have a look at it and most likely fix it (can`t guarantee on very old gear).
As a service, I charge just 25UK pounds plus the cost of returning the unit…. in the case of a VC1 these are quite light so 6 UK pounds should cover it.
If you do send it to me, dont forget to mark it clearly ‘equipment for repair` and enclose a note with the return address!