Background noise when reverb is on?

[guijs]

Hello,

My Mark V started to make a background noise when the reverb is on, but only at ch1. When I hit the reverb switch, the noise fades in. I have checked the reverb tank connectors and it seems fine. Any suggestions?

 

[guijs]

I found the problem. I just got my Mark V after a combo to head conversion. The builder mistakenly inverted the reverb tank position, puting the connectors facing towards the front of the head instead of the back. The ground side of the reverb tank cause this noise when it is too close to the big transformer.

Now I will have to take the head back to the cabinet builder to rebuild the bottom side where the reverb tank hole is located.

 

[guijs]

Does anyone know what kind of metal this plate over the reverb tank on the Mark V Head is made? Is it aluminum? Stainless steel?

The combo comes whith a wood plate, but the head probably need this metal plate to act as a shield.