Bad Cat Hot Cat build ?

[chuckb]

Hey guys I have a Bad Cat Hot Cat clone that I built and it's giving me some trouble. When playing for awhile maybe 10 to 20 minutes sometimes longer my amp starts to hum loudly,like the sound you get when you touch the end of you guitar cord before you plug it into your guitar. I've switched the standby to off and back on again and sometimes it goes away. I could be playing for an hour and everything is ok and then HUM! I shut the amp off and turn it on again right away and it goes away but eventually comes back.I've checked all the solder connections and swapped out the preamp tubes but nothing changes. Could it be a coupling cap or a resistor breaking down when the amp heats up? Could it be the power tubes/rectifier tube?Any help here would be greatly appreciated.

Thanks,
Chuck.

[chuckb]

anyone got any suggestion?

[chuckb]

Hey guys never mind,found the problem. Shorted preamp tube.

Chuck.

[Chuck H]

Damn... I almost said preamp tube too!!! It was such an obscure problem that I couldn't peg it down. When that happens it's often a preamp tube doing something wierd.

Glad it was easy.

Chuck

[chuckb]

Hey Chuck,
Yea,I don't have a tube tester ,so I took it to a friend of mine who has one and sure enough it was a shorted preamp tube. Thanks for your reply.

chuck.

[drewl]

I've repaired a few original Hot Cat's and they're pretty hard on tubes, hope yours isn't as bad!

[chuckb]

Hey drewl, I don't know how it'll be on the tubes yet, as I've not played it much. I'll just have to wait and see when I get some hours on it. Hopefully it won't be to bad.

Chuck.