Intermittent hiss from Boss TU-2 tuner

Is this a common problem? Is there a fix?

I've got a Boss TU-2. It's the first pedal in my chain. It's powered (as are four other pedals) by a Visual Sound 1-Spot.

I'm using the regular output that mutes the guitar signal when tuning...but I'm getting a hiss when I tune. It only occurs when the tuner's display is lit; if I palm-mute my strings so the tuner's display goes out, the hiss goes away. As soon as I pluck a string and the display lights back up again, the hiss comes back.

This happens with no other pedals active, but a fair amount of gain on the amp. Any ideas on a remedy? Thanks.

It's possible that it could be the One-spot. Some combinations of pedals all powered by the onespot can get noisy (while some others will be dead quiet). What are your other pedals? Perhaps one's power jack is "center-positive". That would cause noise for sure.

Experiment a little... try the tuner powered by the onespot but with nothing else in your chain. Still noisy? Then try a battery. If not, add your other pedals one-by-one until you find the culprit.

Are you sure it's not just single-coil noise when you are not touching strings?

One thing to try is flip the OneSpot plug around. Another is isolate the transformer from noisy interference-causing things like PC's, etc.

I doubt it is the TU2, although Ive been wrong a few million times.

Definitely not single-coil noise; it happens with 'buckers, too.

Thanks for the troubleshooting ideas, guys. I've known since the problem cropped up that I'd probably just have to go through the old process of elimination...but I thought I'd post just in case it was a common problem with a known solution. :grin:

For what it's worth, the other pedals are (in order after the TU-2) a Dyna Comp, a BYOC Overdrive, a Voodoo Lab Micro Vibe, and a Hardwire DL-8 delay. I think they all have the standard PS connection.

Are there pedals that are "on" after it in the chain when you use it (dirt) ?

Are there pedals that are "on" after it in the chain when you use it (dirt) ?
No. This happens with no other pedals active.