Chasing an amp hum

Steve Rosko · From: Georgetown, Texas

My signal chain is Emmons (original pups), black box, Hilton pedal, Sarno V8 pre amp, Benado effects, Quilter tone block 200. I use George L cables I assembled myself. If I turn up the gain on the tone block Iâ€™m getting a noticeable hum. Iâ€™ve gotten away with it for a long time playing in small venues, but played in a larger venue and the sound guy heard it in his headphones. If I turn up past 40% or so itâ€™s unplayable. I tried plugging everything into a power conditioner with no effect. I unplugged everything but the tone block and removed the input to the tone block: no hum. I plugged a spare cable into the input on the tone block with the other end of the cable just loose (not plugged into anything): got the hum. I then plugged a spare George L cable end only (no cable attached): no hum. So, itâ€™s gotta be the cable picking up interference?
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84 Emmons D10 PP, MSA D10, Hilton, Little Walter PF89, PF-350 cabs, blueSky, BJS

Jack Stoner · From: Kansas City, MO

A loose cable can sometimes cause hum so that was not a good test.

Start by plugging guitar straight into the Quilter, Do you get hum? If no hum, plug one item in and see if you get hum. Then another until you find what is causing it.

I had a Black Box and it introduced ground loop hum. Only way I was able to eliminate it was to use an AC power "ground lifter" adapter for the BB's AC power.

That's quite an array between the guitar and amp, and many potentials to introduce ground loop hum.

I used to use George L's cables exclusively for 38 years with Peavey amps. But they were too much (highs) for a Quilter. I went to regular run of the mill guitar cords and there was the sound. Both on a Quilter Steelaire and on my Travis Toy 12 combo (TB202 amp).
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Steve Rosko · From: Georgetown, Texas

I know my post was a little long, but I was trying to provide good data. To summarize:

I bypassed everything but the Tone Block power amp. Guitar to tone block power amp = hum. Unplug guitar, but leave cable plugged into tone block = hum. Unplug cable from tone block input = no hum. Plug George L jack without cable attached into tone block input = no hum
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84 Emmons D10 PP, MSA D10, Hilton, Little Walter PF89, PF-350 cabs, blueSky, BJS

Dick Wood · From: Springtown Texas, USA

You will get a hum if you unplug the cable from the guitar and leave it plugged into the amp.

Try a different cable(s) and see if the hum changes or goes away. I've used George-L's for years with no problems until recently.I changed various cables out until I found it was a George-L that was causing the hum in my case.
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J Fletcher · From: London,Ont,Canada

Single coil pickups ? They are usually the culprit .

Steve Rosko · From: Georgetown, Texas

I get the hum without the guitar plugged in...
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84 Emmons D10 PP, MSA D10, Hilton, Little Walter PF89, PF-350 cabs, blueSky, BJS

J Fletcher · From: London,Ont,Canada

A cable plugged into an amp will hum if it's not plugged into a guitar also . Both ends have to be plugged in . Steel to volume pedal , to amp . Volume pedal in off position . Hum ?

Steve Rosko · From: Georgetown, Texas

Yes. I tried guitar directly into the tone block basically bypassing everything including the pedal and I get the hum. I get the hum going through the pedal regardless of pedal position. This all happens when I have the gain turned up on the tone block.
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84 Emmons D10 PP, MSA D10, Hilton, Little Walter PF89, PF-350 cabs, blueSky, BJS

b0b · From: Cloverdale, CA, USA

George Biner · From: Los Angeles, CA

Everything is plugged into the same electrical outlet, right? Is there something creating a strong magnetic field around there (shot in the dark)? Do you have fluorescent lights? Have you tried a different outlet / different circuit?

I haven't seen that a cable plugged in with the other side unplugged causes hum -- buzz, yes, but not hum. But do try a different cable there.
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Jim Kennedy · From: Brentwood California, USA

Try another guitar. Ground problems with an instrument can cause hum. I just went through this with my Tele.
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Michael Hill · From: Arizona, USA

You can't leave 1 end of the input cable plugged in to nothing. You can use an alligator clip lead or something similar to short the end of the cable so it's not floating.

John McClung · From: Olympia WA, USA

Steve, a laptop too close to your guitar pickup will cause a maddening hum. I had an older MacBook that was the cause of hum I couldn't track down. It lived too close to my steel for Skype teaching purposes. A newer Macbook Pro doesn't cause nearly the problem.
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Tom Campbell · From: Houston, Texas, USA

Just went through the same thing. It was my single coil pickup!!!

I tested my cables using my regular six string guitar with humbucker pickup, regular guitar cords, a stage-one volume pedal and into a Evans E-200 amp. Cranked it all up to almost FULL volume...quiet as a church mouse.

Used the same set up only this time using my steel with the single coil pickup and "all h-ll broke loose.

Jim Kennedy · From: Brentwood California, USA

Check the grounds on your guitar. Yeah, single coil pups are noisy, but a bad ground will amplify it 10 fold. My Tele was horrible for no good reason at a gig a week ago. Could not play even at low volumes. Bad ground.
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Stephen Cowell · From: Round Rock, Texas, USA

Get one of those gray 3-to-2 AC plug adapters and go through your equipment one at a time... there's always problems when connecting a bunch of power-wire-grounded stuff together... it's called 'ground loop'. Plugging everything into the same outlet strip will help... some.

https://en.wikipedia.org/wiki/Ground_loop_(electricity)
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Steve Rosko · From: Georgetown, Texas

This has been a real journey, but if anyone's interested here's what I found out: I had several issues contributing to noise, but the main problem turned out to be the direct out from my Quilter Tone Block 200. I set up my recording interface and had one input from the direct out on the Tone Block 200 with another input from an e906 mic hanging in front of one of my speakers. The mic input was quiet, but the direct out had a level of base noise that was quite high and obvious on the recording software. This base noise is apparently what the sound guy heard in his headphones that started me on this adventure.

Other changes I made while diagnosing all this: I had Scott Swartz rewire my pickups, I rewired the Emmons with a new neck selector switch and output jack and changed all my cables from George-L to Mogami (that I made up myself). In talking with Sage Benado, he recommended I try my effects before the volume pedal which I did (not necessarily for noise but for improved effects). All these secondary changes happened more or less at the same time so it's hard to pin down what did what, but my overall tone improved; two of my band members noticed. There were a couple other changes, but I'm trying not to write a novel here.

Thanks to Larry Behm, Lynn Stafford, Scott Swartz, Brad Sarno and Sage Benado for patiently helping me.
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84 Emmons D10 PP, MSA D10, Hilton, Little Walter PF89, PF-350 cabs, blueSky, BJS

Jack Stoner · From: Kansas City, MO

I would contact Quilter. The TB200 shouldn't be noisy.
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GFI Ultra Keyless S-10 with pad (Black of course) TB202 amp, Hilton VP, Steelers Choice sidekick seat, SIT Strings
Cakewalk by Bandlab and Studio One V4.6 pro DAWs, MOTU Ultralite MK5 recording interface unit

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