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I have two champs, one from '75, one from '69. They both hum obnoxiously when I play them with a strat, and I'm pretty sure it's not the normal hum of a single coil pickup. The source I think has to do with the wiring in the house, because I've used them elsewhere and noticed significantly less hum 
So for now, is there anything I can do to the amp to try and reduce it? I record too so it's going to be apparent during silence.
Here's what I've done so far:
to the '75, I replaced the electrolytic caps in it, the cathode bypass and the can cap. I got a little more gain out of the deal but there's still much hum. The '69, I bought it with the original two prong AC cor and I put a three prong cord on it to ground it, now it only hums when I am plugged in, rather than just having it being on all by itself. I've switched the power tubes between the two and nothing changed, and I switched the rectifier tubes between the two and nothing changed. I have many different 12AX7s and none of them improved the situation.
Concerning the type of hum, being 60Hz or 120Hz, I don't know how to tell the difference really, but I recorded the hum and I tried using EQ to filter it out, but I found that there wasn't much energy at all at 60Hz or 120Hz, most of it was between 1kHz and 8kHz, and I tried filtering out certain overtones of the 60Hz and it didn't do much either. I dunno if that helps in determining the problem
Any help is appreciated.
So for now, is there anything I can do to the amp to try and reduce it? I record too so it's going to be apparent during silence. Here's what I've done so far:
to the '75, I replaced the electrolytic caps in it, the cathode bypass and the can cap. I got a little more gain out of the deal but there's still much hum. The '69, I bought it with the original two prong AC cor and I put a three prong cord on it to ground it, now it only hums when I am plugged in, rather than just having it being on all by itself. I've switched the power tubes between the two and nothing changed, and I switched the rectifier tubes between the two and nothing changed. I have many different 12AX7s and none of them improved the situation.
Concerning the type of hum, being 60Hz or 120Hz, I don't know how to tell the difference really, but I recorded the hum and I tried using EQ to filter it out, but I found that there wasn't much energy at all at 60Hz or 120Hz, most of it was between 1kHz and 8kHz, and I tried filtering out certain overtones of the 60Hz and it didn't do much either. I dunno if that helps in determining the problem
Any help is appreciated.
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