1spot 9v psu Buzz. Is there any cure?

[somnif]

Howdy folks,

I just finished boxing up a pedal, AFTER testing the circuit (it worked btw). I didn't have room for a battery in the 125b so I went out and bought a Truetone 1spot 9v power supply. I get home and... it buzzes. Like a box of angry bees with megaphones. I gator clipped a 9v battery to the DC jack in the box and it's quiet (or as quiet as I get with single coils), but on mains,  its angry.

So I assume "ok, maybe I got a bad unit, easy fix.".  I drive back to GC and swap it for another off the shelf. I get home, and again, little box of chainsaws when plugged in.

Oddly enough I noticed that, if my finger touched the sleeve of the plug on the 1spot as I was going to plug it into the pedal, I could hear a change in the tone of the hum coming through my amp (similar to tapping a guitar cable's tip plugged into an amp). I tried a number of different wall sockets around my apartment with similar results.

Is there any fix you can suggest that could help with this? A dedicated isolated power supply ala Voodoo labs isn't in the budget at the moment, and I was hoping I would have better luck with this device than a re-purposed 9v wall wart from the shelf at Goodwill.

[galaxiex]

I have a couple of 1Spot units and they never buzz in any of my pedals.

My guess would be, there is a ground issue with the pedal.

[HamSandwich]

How is your jack wired? Are you daisy chaining other pedals? What's the pedal?

[somnif]

1776 Rub-a-dub Deluxe, wired up using a gutiarpcb 3pdt switch board ( http://www.guitarpcb.com/PDF%20Files/3PDT%20WIRING%20BOARD%20v4.pdf without a battery clip). I triple checked the wiring and solder joints and they all look fine.

And I tested the 1spot using a couple other pedals and still got buzz (all one at a time). It buzzes with my Boss PH3 phaser and my DOD250. Bypass and engaged. What are the odds I have gotten 2 bad units in a row from guitar center?

[jimilee]

Have you checked it with a multi meter? I have days where the power spikes up past 9v and makes a terrible noise. Irritating really. It goes without saying, but are you plugging it in close to anything? Mine buzzes also when it's too close to my fluorescent desk lamp. At Rej's house (Grindcustoms) line work was being done down the street making his gear buzz. I guess I'm saying it could be coming from anywhere.

[somnif]

Its running between 9.5V and 9.6V (using a harbor freight DMM, so take the values with a grain of salt).

I live in a small apartment so I only have so many options as to where I can plug it in, but I've tried every easily accessible outlet in my place, and it buzzes in all of them. I have a CFL bulb lamp on my desk, my computer, and a small floor fan running, so I imagine there is SOME noise in the air, but not what I'm getting out of the 1spot.

There is still the possibility that the wiring in my place sucks, I suppose, but I was hoping it was something I could fix without a contractor coming in.

[galaxiex]

What kind of amp are you using with this, and where is it plugged in, in relation to the 1 Spot?

This is starting to seem like a ground loop problem.

I assume you always used batteries with your other pedals before you got the 1 Spot?

Do you have means of checking your household wiring to be sure its wired correctly?

Seems very unlikely that you got 2 bad ones in a row, but I suppose it could happen.

[matmosphere]

Is there anywhere else you could try it out? It sounds like the problem is with the wiring in your apartment, but it wouldn't hurt to see the problem still exists if you try it somewhere else.

Also try to make sure that your amp and the pedal are running on separate circuits and see if that helps.

[somnif]

This is using my Fender Mustang 1 practice amp. Its in a separate socket from the 1spot, but I only have 4 socket circuits in my place, 2 of which are in my kitchen. I tried plugging into a separate circuit from the amp and it didn't really help.

Yes I tried batteries with my other pedals, they worked fine. The switch on the 250 is going bad, but the circuit itself is fine.

Unfortunately I am not sure if I have the equipment to test my wiring, and I know for certain I do not have the training. I live in an apartment so maintenance issues are a bit hit or miss in terms of getting "non-essential" work done. I've always thought the wiring was a little iffy given how much single coil noise I get when in my bedroom (compared to the living room), but I do not have an empirical means to test this.

[jimilee]

SO I guess the answer then is no there is no fix for it. You can use a 9v adapter on the outside. Solder a battery snap to a DC 9v power plug.


http://www.taydaelectronics.com/hardware/dc-power/dc-power-plug-2-1mm-x-5-5mm-x-14mm.html
http://www.taydaelectronics.com/connectors-sockets/battery-connectors-holders/9v-9-volt-battery-clip-connector.html

[midwayfair]

Take your amp, guitar, pedal, and power supply somewhere else and test it in a different building. I would bet you can do it at the Guitar Center where you bought the One Spot.

You should also have at least two circuits in your apartment that aren't on the same breaker as whatever you're plugging the amp into: Any outlet in the bathroom and the outlet that the fridge is plugged into (if you have more than a couple appliances in the kitchen, chances are there's at least one more). Run an extension chord for the amp (or the power supply) to some other outlets and see if the buzz goes away.

[somnif]

Thanks for the advice everyone. I did test it on two separate circuits in my place, and the buzz was still there. I will test it at a friends place when he gets off work this afternoon and see if it helps. Otherwise, I will return the unit again and think of something else.

Would an isolated power supply help with the hiss if it is my wiring? Or should I just invest in a lot of batteries for now.

(Also why does Europe get the cheap iso bricks, like the Fame DCT-200 or the Harley Benton power plant jr. . All I can find in that price range stateside are the fake "isolated" units from Joyo and Donner and a dozen other Chinese manufacturers. Blah)