Re: amplifier hum

Steve Hawkins wrote:

George is right. It sounds like a 60Hz, EMI problem and he's covered all the bases.

I'm heading out the door in a few minutes to try and locate an Ebtech. I'm also thinking about trying a DI box. That would give me a ground lift and allow me to plug my electric guitar into my mixer.

It's hard for me to believe that both amps are bad. The Fender amp is brand new and it's one of their better ones.

> Don't forget dimmer switches and flourescent or
transformer based lighting. Baseboard electric heat?

We have oil hot water heat. Can a dimmer switch or flourescent light foul up an entire houses wiring? I've plugged the amps into every circuit in the house and I get the same hum in every one of them. I've checked all the outlets in the house with one of those testers and they're all wired correctly.

I did notice that the hum is at its absolute worst when I hold the input cable perpendicular to the cell phone tower. Moving the cable around has a huge effect on the amount of hum I get. That's why I suspect RFI. The cell phone tower is only a couple hundred feet from the house.

Another source of hum is internal to the amp. I've seen the power transformer couple to the reverb tank in several amps. If the amps have reverb, try unplugging the cables that go to the tank and see if the hum goes away. 

I have no idea how to do that.

Of course it could just be your magnetic personality causing the problem. Have you tried wrapping yourself in tinfoil and grabbing a cold water pipe? :-)

I've been using the tinfoil to keep the government from spying on me but it hasn't helped the hum.

How's that CATH Martin? 

It's having fun swapping Martin factory stories with the D-18 GE I bought.

Tom Reese


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