I just completed a Runoffgroove Umble kit from Officially Licensed Circuits. There is a curiosity about the wiring instructions for the 3PDT switch.
The wiring diagram is on Page 21 of the build guide, .pdf here: http://www.olcircuits.com/olc_umble_buildguide.pdf
When the switch is "on," the signal to the PCB comes from the tip of the input jack, which is connected to the bottom center lug, through the switch contact to the middle center lug of the switch, then to the PCB input.
However, when the switch is "off," the sleeve of the input jack is connected to the signal input on the PCB via a jumper wire than connects the lower left (sleeve) lug to the top center lug, then through the switch contact to the middle center lug, which is connected to the PCB input.
Does the jumper wire essentially "ground" the entire PCB circuit when the switch is "off?"
Quote from: ECDavis on October 25, 2013, 11:43:27 AM
I just completed a Runoffgroove Umble kit from Officially Licensed Circuits. There is a curiosity about the wiring instructions for the 3PDT switch.
The wiring diagram is on Page 21 of the build guide, .pdf here: http://www.olcircuits.com/olc_umble_buildguide.pdf
When the switch is "on," the signal to the PCB comes from the tip of the input jack, which is connected to the bottom center lug, through the switch contact to the middle center lug of the switch, then to the PCB input.
However, when the switch is "off," the sleeve of the input jack is connected to the signal input on the PCB via a jumper wire than connects the lower left (sleeve) lug to the top center lug, then through the switch contact to the middle center lug, which is connected to the PCB input.
Does the jumper wire essentially "ground" the entire PCB circuit when the switch is "off?"
Didn't read to indepth, but its ussually *not always* a good idea to ground the input when switched off
I see it yes, when bypass (switch-off) the circuit input center lug is connected to the jumper wire all the way down to both input/output sleeve which are ground.
The input sleeve and ring carry the ground and they are connected when jack(plug) is inserted.
Hmm...guess it's not "true bypass", in the sense that you'd use it as a pedal...no signal would bypass if it were turned off...
Quote from: GibsonGM on October 27, 2013, 09:06:37 AM
Hmm...guess it's not "true bypass", in the sense that you'd use it as a pedal...no signal would bypass if it were turned off...
Thanks GibsonGM, Hmmm...let me take a second look..
Quote from: GibsonGM on October 27, 2013, 09:06:37 AM
Hmm...guess it's not "true bypass", in the sense that you'd use it as a pedal...no signal would bypass if it were turned off...
I read again page 21, its true bypass. Kindly double check maybe I'm wrong.
This is fairly standard 3PDT true bypass stompbox wiring with circuit input grounding.
Quote from: GGBB on October 29, 2013, 11:11:23 AM
This is fairly standard 3PDT true bypass stompbox wiring with circuit input grounding.
Thanks GGBB, now I owe you two my friend :icon_smile:
Cheers