Ab763 Hum issue Amp played great up until now.

[silat]

My blackface clone has a hum that stays the same level even if you turn the volume all the way down. Has anyone ever had this happen I have let the amp sit and have not played it for awhile and it developed this loud annoying hum at  loud level. In one channel you can play the guitar through and hear it but nothing through the other channel but that hum.

Thanks in advance for any input.

Silat

[Raybob]

What is "a while"?  How old are the filter caps?

[silat]

Filter caps are new. It is a new clone at least a year old. I have let it sit and worked on building other amps.

[silat]

! No longer available

This 60 cycle hum that does not change when you turn the volume up or down is just what my amp is doing.

[silat]

https://www.youtube.com/watch?v=GrVtX0QGNls

The video above says a 60 cycle hum is a tube. A 120 cycle hum which sounds different is a filter capacitor.

[silat]

It was nothing but a bad tube at V6 12At7.... Changed it and it now plays great.