Background hum/buzz

**Badge** · 09-07-2014, 06:02 AM

Wondering if anybody can help.

Here is a photo of my set up. I am running my guitar into a boss splitter then to a tuner then RC 30 looper and then a cube 40. Sometimes I plug an iphone into the RC for backing tracks etc.

An annoying background hum exists regardless of whether I plug my guitar into the splitter or directly into the RC. The hum is not there when I plug directly into the amp.

I know nothing about effects pedals, cables etc. I use the splitter so I can have my bass and a guitar plugged in at the same time and not have to unplug them to swap them. The problem exists regardless of which guitar i play.

I have tried moving the gear to different places around our home and the same problem follows everywhere.

It's very annoying. I like clean and not too loud sound and this hum means I cannot get max enjoyment from what I do.

Thanks!!

**krueger** · 09-09-2014, 05:51 PM

Could it be ground loops? I would suspect that you don't have hum with the pedals on batteries and the amp, but only when you connect the adapter driven looper?

**teok** · 09-09-2014, 06:00 PM

Originally Posted by Badge

An annoying background hum exists regardless of whether I plug my guitar into the splitter or directly into the RC. The hum is not there when I plug directly into the amp.

It sounds like you're saying the RC is the common factor. When the RC is in the path, hum. With the RC out of the path, no hum. Is that about right?

**krueger** · 09-10-2014, 03:07 AM

Some trial and error things I would try before investigating any investments in equipment to clean up the power sources. (Disclaimer: I'm not a professional electrician, hence the trial and error/rain dance approach)

I would try to connect the full setup without the looper, with pedals on batteries to eliminate the possibility of hum coming from any other piece of your equipment, i.e problems in the signal path. I suspect that the looper can't run on batteries, right?, otherwise I would run that off batteries just to see if the hum goes away.

Are you connected to the same outlet with all your equipment? If not try that.

If you are connected to the same outlet, try separating.

Do you have any other electrical equipment connected to the same outlet? If so try and disconnect them.

Do you have dimmable lights? Try to turn them off fully or on fully.

Bring all the stuff over to a friends house and run it off one outlet there and see if the hum persists or not. This gives you a clue about the power/ground "quality" in your own house.

Are you running the correct ac-adapter with your looper (the one that came with the unit) or is it a replacement? I have tried third party 9V adapters for some of my pedals that introducted massive amounts of squeal and noice, while other adapters kept them dead silent. Perhaps try another compatible adapter (make sure you know what you are doing, I have fried a pedal by accidentaly using the wrong kind, and your looper is expensive).

If you read up on ground loops in audio equipment you will pretty quickly see suggestions to lift the ground
Ground lift - Wikipedia, the free encyclopedia
this would be done by a special "cheater plug" that disconnects the ground in your outlet. This of course exposes you to the risk of electrical shock if the equipment gets damaged. The plug is probably cheap and could solve the problem, but running the equipment this way is a calculated risk that you have to decide about yourself. In practice it is a common way for people to solve hum issues, especially if pressed for time (and/or money).

With that said I run all my stuff off old un-grounded outlets in my house, which is the same thing as if I have had a ground-lift cheater plug installed everywhere.

**Badge** · 09-10-2014, 05:24 AM

Thank you to all of you for your suggestions. I will give them a go and report back.

Should I expect some sort of hum when using pedals, even if properly grounded etc., or is it reasonable to aspire to no hum?

**krueger** · 09-10-2014, 07:22 AM

I think it depends on the effect type and circuit-design of the pedal. A maxed out metal distortion pedal will probably hiss a bit even on no input signal when not bypassed.

You probably will have the clearest signal with fresh batteries, better than that would not be possible with adapters on any pedal I think.

**Rob22315** · 09-10-2014, 07:28 AM

What power supply are you using? I got away from using any batteries by going with wall warts (even in my active electric guitar and basses) but some wall warts are quite noisy and some pedals allow this noise to make it's way into the signal. As suggested above, try running your RC with batteries and see if that helps.

Are you near any fluorescent or led lights? Sometimes those are noisy too.

**sparkhall** · 09-10-2014, 07:37 AM

I had a hum when using my Cube 30. Drove me mad! I tried everything couldn't get rid of it and eventually swapped it for a Cube 60 which got rid of the problem.

The difference seemed to be related to the fact that the power cord on the 60 had an earth (ground) and the one on the 30 didn't.

**Badge** · 09-10-2014, 08:35 AM

Righto...

Took the whole kit into the living room away from computers, lamps etc.

Tried all the permutations. The best result was when all 3 pedals were with batteries and not power. This was a pretty good result and I would be happy to run with this - BUT what a pain having to change batteries all the time... Is this what I should be resigned to?

FWIW the power source and daisy I was using was a visual sound 1 spot which I was told was the ants pants.

Even with batteries, there is still a slight hiss (like a shh sound, but very quiet) when I play. Then it dies when I stop. Is that normal?

Maybe I'll take my guitar into a shop and try out a bunch of amps to see if the amp is not quite right... Sparkhall I'll try your trick. My cube 40 doesn't have an earth point either.

Unfortunately I missed out on playing with guitars at school and learning all this stuff. But boy I knew a lot about clarinet reeds!

**michael_bxl** · 09-10-2014, 09:06 AM

Does touching any metallic part of your amp (i.e. scews) or your guitar has any effect on the sound (like a "tic" sound) ?

**Rob22315** · 09-10-2014, 09:33 AM

Absent an obvious grounding issue, it sounds like your 1 Spot is likely creating your hum. The 1 Spot is usually well regarded but perhaps you got a bad copy. Were you able to isolate the hiss to one of the pedals? The hiss is likely coming from the RC but it could be one of the others.

Another potential source is that none of the pedals by themselves is the source but the grounding schemes between them are incompatible. This usually isn't a problem for modern grounding schemes (think older Russian manufactured pedals with weird grounding designs) but I've had issues with 1 or 2 Behringer pedals. The way to test this would be to test each pedal separately, then if there's no hum, try the pedals pair-wise until you see which combo squawks. This is even more unlikely in your case because you only have a tuner and a line selector (in addition to the RC-30) which are electrically simple compared to a distortion or a fuzz or an envelope filter etc.

If you want to try some alternate power supplies, the Snark SA-1 or its predecessor the Danelectro DA-1 can be had for less than another 1 Spot. The DA-1 is slightly quieter than the SA-1 because the DA-1 is traditional analog while the SA-1 is a switching power supply. Either can be had for a little less than another 1 Spot but neither provides as much current at the 1 Spot can provide so you need to be mindful of how much current your pedals draw.

If you need high current and isolated power feeds, you will probably have to resort to the more expensive pedal power bricks like the T-Rex Fuel Tank Jr.

**SamBooka** · 09-10-2014, 11:17 AM

Just sayin... I have an RC2 which is a completely different beast.

Noisy as a F'ing gettup IF I dont give it a dedicated power supply.. damn thing is a juice hog (but I love the pedal)

EDIT: And I have a one spot I dont use. It was fine for the first year and then got noisy with everything I plug it into..

**Rob22315** · 09-10-2014, 11:23 AM

Regarding the hiss being there when you play and disappearing when you stop - this behavior is usually the sign that there's a noise gate somewhere in your circuit. Do you know if any of your pedals include a noise gate feature?

**krusty** · 09-10-2014, 11:32 AM

Originally Posted by Badge

FWIW the power source and daisy I was using was a visual sound 1 spot which I was told was the ants pants.

I have a couple of those and they are put away in a drawer now. I had a single one connected to a Korg tuner in my chain at one point. Nothing else was chained from it. It had a noticeable hum that was quite annoying. I originally blamed the tuner, but after switching to a Boss power supply, I found it was the 1-Spot.

I tested both my 1-Spots alone and chained to several pedals with all the pedals I use, and concluded that the 1-Spot is not clean at all.

**Rob22315** · 09-10-2014, 01:11 PM

Here's an interesting thread about RC-30 hiss and volume issues, along with a solution:

RC-30 issues - The Gear Page

You may be able to find other helpful threads with google. Others have reported hiss problems with some units while some are dead quiet. Where you put them in your signal chain relative to the amp (preamp out vs effects loop) seems to make difference.

Others reported noise issues with the 1 Spot as well. Nothing about a noise gate, perhaps the RC-30 has an unannounced feature to control some internally generated noise that some users notice but others don't.

**cosmic gumbo** · 09-11-2014, 01:48 AM

Originally Posted by Rob22315

Regarding the hiss being there when you play and disappearing when you stop - this behavior is usually the sign that there's a noise gate somewhere in your circuit. Do you know if any of your pedals include a noise gate feature?

I had 2 different Roland 40 Cubes that behaved just like that without running any pedals into it, seems to be the nature of the amp.

**docbop** · 09-11-2014, 02:34 AM

Know anyone with a power conditioner like a Furman it should clean up noisy electric lines. If it works then you need to buy a power conditioner.

FurmanSound.com - Pro A/V Product - PL-8 C

**Rob22315** · 09-11-2014, 04:29 AM

Originally Posted by cosmic gumbo

I had 2 different Roland 40 Cubes that behaved just like that without running any pedals into it, seems to be the nature of the amp.

It's not unusual for an amp to include a noise gate. Two Peavey modeling amps I owned (one for bass - BAM 210, one for guitar - a Transformer 112) had tweakable noise gates built in.

**Badge** · 09-11-2014, 07:58 AM

Well, thank you to everybody for their input and advice.

I borrowed a Fender Champion 40 from my local - it's cheap and cheerful. But I reckon it's a keeper because....

No hum hiss or buzz. I tried it first without any pedals, then pedals on batteries and then pedals on single 1spot. No problem with any of them!! I reckon the lack of an earthing line in the plug of my Cube was the issue (the Fender has an earth line) - but what the heck do I know? I'm just glad the noise has gone. Ah the beautiful sound of silence!!

Cube is going on ebay...

Thanks again