Horrible hum coming from bypass looper - help!

I got some noise through my pedalboard in my practice room. Turned out to be coming from the power outlet. My next step is a Furman power conditioner.

 

Save your money. Those Furman units are a glorified power bar, and their idea of power conditioning is some varistors between the hot, neutral and ground to clamp any transient spikes to ground. They do nothing else with regards to power line noise.

 

This thing looks interesting. Gets really good reviews. Might be worth a try.

 

Test ALL of your patch cables and pedals individually. This reminds me of an extremely weird issue I had, where one pedal would introduce a noise when engaged. Did basically everything you mentioned, sent the pedal for repair, fault couldn't be reproduced. Turned out to be a dodgy patch cable on a completely different part of the board.

Totally counter intuitive, but the problem that appears to be in loop 10 might actually be some weird grounding issue in loop 2.

Good luck!

 

What happens if you bypass the bypass by connecting a cable from the output 10 to input 10 ?

And what frequency hum are we talking about?

 

Could be a pedal with a charge pump making the noise. Bit I also think American Loopers are one of the worst companies out there. I got one completely broken from them and they tried to blame me. They even "took a video of it" to prove the fault was mine. The only way for me to get my money back was to write them a terrible review and tell them I'd remove it if they did right by me. I never even considered them after that was resolved.

 

A charge pump is when a pedal increases the internal voltage, say from 9 volts to 18. Or from 18 to 36. These pedals always introduce a whine or whistle into a bypass looper and there is no way I've found to remove it other than turning off the pedal in that loop.

And you gut feeling on "that side of the equation" may be right. American Loopers is not a company I'd ever do business with again after my experience with their programmable looper.

 

Sounding like one of those has a charge pump in it. Best way to diagnose is to remove pedals one by one and see if the noise stops. If it does, google the pedal in question to see if it does have a pump. If it does, problem solved, although using that pedal might be a problem.

 

Another hunch: could you, while testing, unplug the looper's power source?
I guess it's a simple, passive unit with only the LED's needing power?

 

Sometimes it’s a weird pwr issue. If it can run battery pwr, try that in your trouble shooting.

 

.....it only hums because it doesn't know the words.

 

Always? No they don't. I have two pedals with charge pumps in separate loops of my bypass looper, with no problems no matter what combination of loops I use.