1 Spot Pro and positive ground pedal

[Jay]

Hi,

I built a, battery only, Rangemaster for a friend.  Mullard OC44, positive ground like the original.

He's now bought a 1 Spot Pro CS12 and would like to power the Rangemaster from it.  The 1 Spot says it's all isolated outputs so all should be well?  Is each output of the 1 Spot completely isolated from every other, i.e. no common ground connection between power outputs?

If that's the case I reckon I'm ok to just fit a floating (plastic) 2.1mm socket to the pedal, centre negative. 

[EBK]

With the power off, check for continuity between the output grounds.  I don't know anything about this particular supply, but some manufacturers have a looser definition of "isolated" than others. 

You could always throw a charge pump inside your positive ground pedal to generate -9V from +9V and not worry about this stuff....

[R.G.]

I happen to know the answer to this for certain. 

The 1 Spot Pro (either the CS12 or CS7 models) have isolated outputs. They have no shared ground, and the outputs are independent.

[Jay]

Thought this might catch your attention!  I reckoned that was the case but thanks for confirming.  I'll wire it like it any other pedal, just tell him not to lend it to anyone else with a different PSU!

[R.G.]

The CS12 and CS7 also support daisy-chaining on each output, but your friend will need to be sure that the positive-ground channel is not daisy chained to negative-ground pedals. Chaining to other positive ground pedals is OK.

Hooking it up wrong should not harm either the pedals or the power supply, as there are some fairly elaborate guards built into the power supply to keep it from causing damage. But it will shut down and they won't work.

[Jay]

I don't think he daisy chains but I'll tell him not to.  Good to know no damage either way.  He loves the pedal, and your PSU.  That Rangemaster is on all the time at every gig, think it's done a hundred or so now so safe to say it's staying on that board with the 1 Spot and won't end up powered by anything else.