Amplifier Hum

Try another cable.

I get buzzing unless I am touching anything metal on the guitars including the strings.

This is normal. You only notice it more because humbuckers have a considerably higher output than single coils. With most guitars, you are the ground. There is a ground wire that goes from the back one of the pots where all the ground wires are soldered which is attached to the bridge. With older amps it wasn't unusual to get a bit of a shock from the guitar if you were standing bare foot or wearing socks.

I disagree about that. The guitar hardware is all supposed to be connected together and grounded through the outer shield of the instrument cable to the amp chassis, through the outer connector of the jacks on the guitar and the amp. Humbuckers do have higher output than a Fender single coil, but as the name implies the two coils are balanced so as to cancel out hum picked up by the pickups.

It's quite possible that the bridges of the two humbucker-equipped guitars aren't properly grounded to the guitar electronics, and you're grounding them when you touch the strings. The Fender doesn't hum because it's properly grounded.

Maybe I've been playing poor guitars all my life but I've never known a guitar that didn't have some hum when you aren't touching metal on it. Turn up the amp good and loud with your Strat and see if you can duplicate the hum. If not I stand corrected but something tells me that as soon as you let go of the guitar there will be hum.

Yeah, there'll be some hum always and touching the metal will affect it, but he said the Strat didn't hum and the two with humbuckers did. That's the opposite of what you'd expect, and indicates something's funny about the humbucker equipped ones.

Thank you to those who have provided feedback. I seem to have narrowed it down.

It is not the guitar cord as I purchased a very expensive high shielded cord and gained no improvement. I can return it and get my money back.

I also borrowed a small solid state practice amp and there is no noise using the humbuckers through that amp even with the gain pegged.

I guess that I should assume it is some type of an issue with the amp and the humbuckers. My next step is to try another tube amp with the humbuckers to rule out the guitars.

Any ideas?

Thanks.

Bob

Curious. Is there a ground lift switch on that amp?

The amp has three toggle switches, power, standby and ground. Switching the ground has no effect on the problem.

The amp is the Fender Delux Reverb Reissue and appear to have been manufactued in the early 90's.

The problem could be a result of poor grounding or incorrect wiring of the electrical system into which the amp is plugged. I can't tell you how many times I've seen house wiring where the resistance to actual earth ground of the electrical ground at outlets' "ground pin" is extremely high. The other thing I've seen even more often is where the neutral is wired to the incorrect side of the electrical outlet, even sometimes all the way back to the electrical breaker/fuse panel being wired incorrectly as to hot/neutral.

Also, beware of fluorescent lights, TVs, PC monitors (mostly CRT-type), light dimmers, and furnace/hot water heater gas electrical igniters, to name but a few, as these are all sources of electrical noise and hum that can be problems. I haven't looked, but I'd take a look at the studio/recording forums for threads dealing with noise also, as they may have more on this subject. Good luck. :)

Cheers!

Strat