With an AB pedal (not ABY), is there need for a ground lift without the option of both outputs hot at once?
I used this drawing: http://www.beavisaudio.com/Projects/Looper-Switcher/A-B-Switch-Dual-LED.png
In some environments the power for the LEDs causes hum. Is a ground lift the cure for this? If so, what does it ground to?
> power for the LEDs causes hum
In that plan: the signal ground has NO connection to the LED-power ground. (EDIT: Did you use a metal power jack?)
Also your power should be hum-free.
Need to say more about what you built.
And Welcome.
Quote from: PRR on April 17, 2014, 01:07:26 AM
> power for the LEDs causes hum
In that plan: the signal ground has NO connection to the LED-power ground. (EDIT: Did you use a metal power jack?)
The power jack is plastic. All TS jacks are metal, but as you said, not contacted to the power ground.
Quote from: PRR on April 17, 2014, 01:07:26 AM
Also your power should be hum-free.
Is this true for all environments? I thought people buy power conditioners to clean up noisy power.
Quote from: PRR on April 17, 2014, 01:07:26 AM
Need to say more about what you built.
And Welcome.
I followed the drawing. I'm "sure" I have it all wired correctly. I'm not so much asking what I did wrong as much as I'm asking what can I add to the pedal for noisy rooms. Not a cure-all of course, but would a ground lift fix this kind of hum. Or even... what could the hum be. Has to be power related, right? The pedal is silent without power for the LEDs.
And thanks!
Did you wire it so the input not used is grounded when not in use?
I have about the simplest one you can make with LEDs to show which input is active and it has zero hum.
I use it for switching,amps,FX chains,or even guitars.
There is no power going to the actual switching circuit,it simply powers the LED's
I might check the grounds with a multimeter just to formally remove it if you haven't already. Otherwise, if it isn't a ground loop and is dirty power and isn't a problem with the pedal itself; if I had the choice I'd clean it up earlier in the chain and let all pedals enjoy that benefit. :) In a perfect world, I know, just throwing it out there.
Quote from: Brymus on April 17, 2014, 01:52:05 PM
Did you wire it so the input not used is grounded when not in use?
I followed the drawing, so as best I can tell, yes.
Quote from: Brymus on April 17, 2014, 01:52:05 PM
There is no power going to the actual switching circuit,it simply powers the LED's
That's what I thought which is why I'm confused/I don't think the pedal is the root of the hum.
Quote from: karbomusic on April 17, 2014, 02:17:54 PM
I might check the grounds with a multimeter just to formally remove it if you haven't already. Otherwise, if it isn't a ground loop and is dirty power and isn't a problem with the pedal itself; if I had the choice I'd clean it up earlier in the chain and let all pedals enjoy that benefit. :) In a perfect world, I know, just throwing it out there.
Agreed. I'll look into these after the weekend. Thanks guys.