Chorus pedal hum

Wooly · #1 02-11-2017, 03:17 PM

I have 3 guitars equipped with K&K pure mini's in them. When I use my Boss chorus pedal with an AC adapter, there is no hum. The other guitar has a Fishman Neo D humbucking sound hole pickup and I get hum when I kick the chorus on. (It's quiet when the chorus is off.) However, when I install a 9 volt battery instead of AC, all is quiet. I have another cheap Dean Markley sound hole pickup that I thought I would try and it also hums with the AC adapter.

Any ideas as to what's going on?

YamahaGuy · #2 02-12-2017, 06:20 PM

Plug the pedal into the same outlet the PA is plugged into if at all possible. People think I'm nuts, but when I set up at a gig, everything in my rig gets plugged into the same outlet. No hums that way.

In the past, I'd plug a powered speaker into a convenient outlet, and major buzzing. One place I play, I dont use pedals because I get the same buzz.

It's something in the electric. A DI box may be able to fix the problem, but if you can, try plugging the ac adapter into the same outlet as the PA system. Good luck.

Bill Yellow · #3 02-13-2017, 03:53 AM

Quote:

Originally Posted by YamahaGuy

People think I'm nuts, but when I set up at a gig, everything in my rig gets plugged into the same outlet. No hums that way.

That's not nuts, that's the textbook way to deal with earth loops - hum produced where the earth cable voltage from different outlets is not the same.

However, that's not the OP's problem as I understand it. He gets a hum when using soundhole magnetic pickups but not when using the K&K's.

jonfields45 · #4 02-13-2017, 07:25 AM

Try a different power supply. I would recommend a quieter one, but all of them are built to such a low price point and probably only tested for basic function when manufactured.

LSemmens · #5 02-13-2017, 07:37 AM

It could be something as simple as an impedance mismatch (unlikely), however, given that it is only an issue when plugged in, I doubt it. What sort of power supplies are you using? Are they just wall warts or designed specifically to power pedals? As has already been stated, Always plug into the same outlet as your amp. Even then, sometimes, the only solution is to run on batteries.

Wooly · #6 02-14-2017, 08:17 AM

I have my amp and AC adapter plugged into the same power bar. I tried a different wall outlet with the pedal only but it didn't make any difference.

I don't understand why it's dead silent with the K&K's but not with the humbucker. I guess if it comes down to it, I'll use a 9 volt battery.