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Hi everyone,
I've been working on a Guyatone PS107 Moving Box Flanger, after a search online I found out that the PCB was identical to a Vox flanger, schematic attached.
What happened so far:
This pedal suffered from a corroded potentiometer, which caused a short in the circuit (I think) - the diode to ground in the power supply section kept running very hot. After replacing it and tweaking the trim pots, I was able to get the flange effect back, but the LED switching was not working.
I figured I'd convert the pedal to true bypass, to circumvent the problem, so I installed a 3PDT switch, but without modifying the rest of the circuit. Initially, there was a DPDT switch with input, effect out and output connected.
After connecting the pedal back to 18V DC, the 2SC-1175 transistor at the beginning of the power supply circuit started smoking and almost split in half, leaving me wondering what happened, and what to do next.
The problem:
I've been trying to understand where I went wrong, and how to proceed. I removed the transistor for now, which means the 18V DC is connected through a diode to ground (2SC-1175 collector used to be here), as well as a resistor and 22uf capacitor to ground (2SC-1175 base used to be here). It is also connected from the same spot through a different diode to the LED. As far as I can tell, nothing connects the 18V to the rest of the circuit.
The question:
Can I simply bridge where emitter and collector used to be, to get DC voltage to the circuit? Also, why is there a diode between the 18V DC and the LED, is this necessary?
Any help would be greatly appreciated!
Edit: I tried bridging the emitter and collector (with the SAD1024 removed, just in case), but D3 in the schematic ran very hot again. I also tested D1 which seems to be fine, but I think the LED blew at some point..
I've been working on a Guyatone PS107 Moving Box Flanger, after a search online I found out that the PCB was identical to a Vox flanger, schematic attached.
What happened so far:
This pedal suffered from a corroded potentiometer, which caused a short in the circuit (I think) - the diode to ground in the power supply section kept running very hot. After replacing it and tweaking the trim pots, I was able to get the flange effect back, but the LED switching was not working.
I figured I'd convert the pedal to true bypass, to circumvent the problem, so I installed a 3PDT switch, but without modifying the rest of the circuit. Initially, there was a DPDT switch with input, effect out and output connected.
After connecting the pedal back to 18V DC, the 2SC-1175 transistor at the beginning of the power supply circuit started smoking and almost split in half, leaving me wondering what happened, and what to do next.
The problem:
I've been trying to understand where I went wrong, and how to proceed. I removed the transistor for now, which means the 18V DC is connected through a diode to ground (2SC-1175 collector used to be here), as well as a resistor and 22uf capacitor to ground (2SC-1175 base used to be here). It is also connected from the same spot through a different diode to the LED. As far as I can tell, nothing connects the 18V to the rest of the circuit.
The question:
Can I simply bridge where emitter and collector used to be, to get DC voltage to the circuit? Also, why is there a diode between the 18V DC and the LED, is this necessary?
Any help would be greatly appreciated!
Edit: I tried bridging the emitter and collector (with the SAD1024 removed, just in case), but D3 in the schematic ran very hot again. I also tested D1 which seems to be fine, but I think the LED blew at some point..
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