Compressor Hisses with Ungrounded Power

[uaudio]

I have a One Spot power supply powering my chain. X2 wireless, Demeter COMP-1 (using the One Spot combo pack reverse polarity plug), and PitchBlack in that order. The One Spot plug does not have a ground, just the two prongs.

When I am playing the bass with a instrument cable, I have no problem. But when I play wirelessly, which I do when I play out, I can't have the Demeter powered by the One Spot cause it hisses. Not a great thing since I leave the compressor on always.

I assume this is because my bass and I aren't completing the circuit/acting as a ground? Can someone explain this to me and maybe help me fix it? I'm sick of buying batteries.

[bongomania]

As you noted, the ground connection to the OneSpot is not the only ground connection. The patch cables also carry the ground, and often (not always) connect to the metal chassis of the other gear as well. You can solve the problem by ensuring that the X2 is grounded, or that there is a wire from an exposed/accessible ground point (like the metal sleeve of a plug, or metal threaded jack, or common-connected metal housing) to an available ground point. That ground point can be some exposed plumbing, or a metal rack of gear that is grounded, or maybe you could even connect the wire to the third prong of an otherwise unconnected 3-prong plug (from a hardware store) and plug that into a grounded outlet.

[zombywoof5050]

You might have a bad One-Spot.

I have two One-Spots, and they both worked well with my Demeter Compulator (no hiss or anything). Then one day, out-of-the-blue, I started get a hissy swooshy sound when I engaged the Compulator. It turned out to be one of my One-Spots that went bad, because the Compulator still works fine with the other One-Spot, as well as the Dunlop ac adapter that I bought along with my Compulator. It's strange, because the bad One-Spot still works fine with my other pedals, it only makes the noise with the Compulator.