Howdy from Dublin, Ireland
Doing a restoration on a 1981 Vox AC30 (Rose Morris Era)- replacing the power tubes (el84) and the main power capacitors which look to be original. Works fine but has a bad hum which is constant and ever present on all channels and with no instrument/ cable connected.
There are three main power ones a large 100 60/100uf double capacitor can and two smaller ones rated as 50+50uf and 32+32uf respectively.
The wiring on the 50/50 cap has red wires and yellow wires connected to similarly marked lugs and then a silver/ unmarked cable attached to a plain lug with no colour.
The replacement caps from JJ Tubes (like for like for the 50 and 32 double caps and a double 100uf one which i understand can replace the 60/100 one) have no colours on them but two positive (marked +) terminals and a negative terminal (marked -)- see pics.
My instinct is that the caps are effectively two similar capacitance caps in one enclosure so it possibly doesn’t matter which + I connect the red or yellow to and the uncoloured cable goes to negative.
However very new to all this and some guesswork involved here so I’d be grateful for any advice or confirmation/ correction on the foregoing.