Ground loops or something else?

[Coma]

Extending my pedal quiver and since I just recently bought a PSU, I don't really feel like getting another one. Decided to try to daisy chain them. Turns out two of my pedals have DC outputs, so I tried to connect one through the other. Got a horrible, whining type of noise. Disconnected and reconnected through a daisy chain cord - noise gone. So, I'm happy the problem is solved, but anybody wanna shed some light on what happened? The PSU has all outputs isolated.

 

[Darg1911]

Re: Ground loops or something else?

Outputs on the supply may be isolated but running a daisy chain doesn't isolate the pedals connected to it from one another. When you plugged the pedals together are you sure you didn't plug a DC output into a DC output (or input to input).?

 

[Coma]

Re: Ground loops or something else?

Ya, fairly certain. Double and triple checked.

 

[VinceT]

Re: Ground loops or something else?

Is one of the pedals a digital unit? They often need an isolated power lead (not daisy chained) otherwise they get feedback from the other pedals. That Pedal Show did a demo of this, I think - let me go look.


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[VinceT]

Ground loops or something else?

I think it was this one https://youtu.be/4XRCjHxaYkc

I'd suffered from noise on my board right up until I watched this, and separated out my digital pedals (I use a TRex Fuel Tank Chameleon) Now it's much, much better.


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[Coma]

Re: Ground loops or something else?

Is one of the pedals a digital unit? They often need an isolated power lead (not daisy chained) otherwise they get feedback from the other pedals. That Pedal Show did a demo of this, I think - let me go look.


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Boss NS2 and Korg Pitchblack.

 

[devastone]

Re: Ground loops or something else?

Seems like I had a Pitchblack years ago that was noisy running on a supply.

 

[dystrust]

Re: Ground loops or something else?

Seems like I had a Pitchblack years ago that was noisy running on a supply.

My Pitchblack is quiet, but I have it on an isolated output.

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[Coma]

Re: Ground loops or something else?

Yeah, mine to. Dead silent

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[dystrust]

Re: Ground loops or something else?

Usually daisy chain issues are caused by a particular pairing of pedals. I've chained 5 pedals off of my Pitchblack with no issues, so there must be something about the NS-2 that doesn't play nice.

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[Darg1911]

Re: Ground loops or something else?

Usually daisy chain issues are caused by a particular pairing of pedals. I've chained 5 pedals off of my Pitchblack with no issues, so there must be something about the NS-2 that doesn't play nice.

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Yes. but if he used the Pitchblack DC output into the NS-2 and got the noise ... then daisy-chained the same two pedals off of a single output of the supply and got no noise. They are still sharing the same ground either way. Must be something internal to the Pitchblack and it's DC output jack that the NS-2 doesn't like and is in some way different than sharing a ground from a single output of the supply itself. Either that, or we don't have the whole story.

 

[Mincer]

Re: Ground loops or something else?

Sometime the noise can increase or decrease with different outlets or different buildings. I've had pedalboards hum louder than the guitar signal at some clubs with sketchy wiring.

 

[Coma]

Re: Ground loops or something else?

Sometime the noise can increase or decrease with different outlets or different buildings. I've had pedalboards hum louder than the guitar signal at some clubs with sketchy wiring.

yeah, so I've heard. haven't had any such issues where I keep my gear, though. The whoel bulding is several floors of rehersal spaces for rent, so that doesn't seem to be an issue. Generally, anyway. We DID have some problems a while back when we were trying to record guitars and our DI box somehow sarted pickung up signals from another band's singer's PA system playing next door. Weird sh*t.