Build Issue

jrjr

New member
Hello, first time inexperienced builder here. Ive built 1 effect prior to this one using stripboard.

Ive been having an issue with a build for the thermonic distortion. I tried being meticulous with my soldering, placement of parts, etc.
The only issue that I caught was with the LED polarity...I had all of them backwards according to the 'led polarity' forum post. Unsoldered & flipped them around.
I got everything together & was fairly excited to try it out. Bypass footswitch worked, but no output from the circuit.
One thing that I noticed was the LED on the board at the in/out portion that goes to the foot switch.
It stays on regardless even if the footswitch is in bypass mode. It gets a little brighter when the switch is engaged.
Im just trying to figure out where Ive gone wrong or what to look for in order to get this circuit to work.
Any ideas would be welcome. Thanks
 

jrjr

New member
Yes it appears to be installed the way the pic shows. Ive attached a photo below.
Hmm.... is there a way to wire it up without the switch (always on) so I can rule the switch out?


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PedalPCB

Solder Sniffer
Staff member
Disconnect the white wires from the IN / OUT pads of the 3PDT board and solder them directly to your jacks.
 

jrjr

New member
Ok I disconnected those wire.....
When I connected to power, one of the LEDs on the pcb lights up (of the four, the one at the upper left)....the LED at the pad to 3pdt switch stays on.
I disconnected the power & reconnected...that LED on the board doesnt light up but the pad one still stays on.
Engaging the switch makes it get a little brighter too.
I'm wondering if I have a cold solder connection somewhere or a bad component.

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Last edited:

PedalPCB

Solder Sniffer
Staff member
If the footswitch doesn't toggle the LED on and off there is some sort of wiring / connection problem at the bottom of the PCB where the LED / wiring pads are.

Disconnect the 3PDT board entirely from the main PCB to eliminate the switch / wires / adapter PCB as the problem.
 

chongmagic

New member
You should connect all wires in blue to the PCB, the purple connects to the tip of the input and output jacks.
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jrjr

New member
Thanks for the input & guidance. I appreciate all the help with this.

I disconnected the 3PDT from the main board.
Both LEDs stay lit up....top left of the grouped four & the one at the bump out to the 3dpt (which I have wired to a led holder).
Still nothing. I'd think I would get at least some sort of scratch noises out of the amp.

I'm thinking I have a short or damaged part somewhere since the 3PDT switch worked to bypass the signal.
So I know the input/out put jacks were connected ok.

I may have to rework all my solder connections to find the culprit.
Or redo the entire build.
 

zgrav

New member
If the LED near the holes for the bypass switch stays on all the time it means there is some path to ground between it and the hole that goes to the footswitch. Since the LED gets brighter when you press the footswitch, it means that the alternate path to ground is going through some type of resistance, maybe a short to your audio path. Try disconnecting the SW wire from the DPDT board. If your LED still lights up you need to find out where it is shorting to ground on the main effect board. If the LED goes off when you remove the SW wire from the DPDT board, it means something on the DPDT board where the SW wire was soldered was shorting to ground. Solving that problem might or might not fix the sound issues, but it is a good place to start where you can fix at least one issue.
 

jrjr

New member
Thanks for the insight. I disconnected the 3DPT switch entirely from the pcb.
I tried reflowing some of the connections to various components. Nothing.
Then I accidentlly pressed on the LEDs (two on left side) and I could get some sound to come thru.
I reflowed the solder to them and now I can get sound.

I can get the volume to definitely work now. I can tell that bass, treble, presence seem to work.
In total, its a clear tone. But no gain.
I think those LEDs are part of the gain circuit & I might have damaged the tracing when I reversed the LED polarity.
I didnt have a solder sucker till today.

Maybe there is still a short that bypasses the gain part of the circuit.
 

zgrav

New member
Congrats on getting sound through the effect. When you disconnected the footswitch did the LED near those hole turn off? If so, something in that connection was keeping it turned on even when the switch was off. If that LED is still on you need to figure out why -- it should not be on unless it is connected to ground through the footswitch (or if you connect that wire on the board to ground). You can check the circuit diagram in the build documents to identify the parts around the gain control that you should check.
 

jrjr

New member
Yeah I think it is the LEDs that are shorting out or not making a good connection.
I must have screwed up the pcb when I was reversing the polarity....haha.
Might help someone else in the future to put that LED polarity info in all the build documents or a link to a pdf of some sort.
Oh well, learned that I need to improve my technique & solder better.
Got a good solder sucker now, the Japanese brand "engineer SS-02".

Are there any diagnostic tools that are recommended...like part testers, oscilloscope, etc etc?
I'm thinking of testing parts out before I install them.
 

PedalPCB

Solder Sniffer
Staff member
Typically with clipping diodes it doesn't matter which direction you install them as long as you install all of them using the same method.

There are some special cases, but they are rare.
 

jrjr

New member
Oh ok I didnt know that....if I'd just left them like they were......haha
Oh well, I panicked & dug around with the soldering iron to get them out...must have damaged the pcb
I'll try to make a new build again soon
Thanks for all the help & insight.
 
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