# Troubleshooting Son of Ben Preamp Pedal



## marksescon (Oct 22, 2020)

Good evening.








Currently working on the Son of Ben (Benson Preamp) pedal. I am not getting sound when the pedal is engaged - however, the LED is turning. Furthermore, I have built an audio probe, and it appears the signal drops when I reach C6 in the schematic.

To note:

I used jumpers for the dual gang pot because I get paranoid about having to troubleshoot and resolder parts.
Utilized the SMD pre-soldered JFETS (J201) from PedalPCB. Did some weird jumpering on Q1 and Q2 and soldered in some pin headers for Q3. Not the most eloquent work but I am getting “voltages” on the Drain (see below).
These are voltages:

Q1 Drain: 3.9
Q2 Drain: 4
Q3 Drain: 4.36

I am willing to concede that reflowing my joints will help in the problem; however, I’m clueless as to why or how the signal is dropping from C6. I’ve even gone so far as to replace the part/component under the guise that I was faulty. Despite my efforts, the pedal is still not functioning and no signal is passing through.


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## okstateblues (Oct 22, 2020)

Can you take a closer photo for details on the solder joints? Also I recommend some isopropyl alcohol and a scrubbing for the back of your board to help clear any residue from soldering


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## marksescon (Oct 23, 2020)

okstateblues said:


> Can you take a closer photo for details on the solder joints? Also I recommend some isopropyl alcohol and a scrubbing for the back of your board to help clear any residue from soldering


Good morning, here are the relevant photos.


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## okstateblues (Oct 23, 2020)

I would suggest reflowing your joints. Looks like your not getting full penetration through the board for both holes on the PCB. I would reflow all your joints just to clean them up a bit. It may solve your issue. If you're new to soldering, youtube is quite helpful for tips and tricks.


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## marksescon (Oct 24, 2020)

okstateblues said:


> I would suggest reflowing your joints. Looks like your not getting full penetration through the board for both holes on the PCB. I would reflow all your joints just to clean them up a bit. It may solve your issue. If you're new to soldering, youtube is quite helpful for tips and tricks.


Thank you! I will work on those. 

I’ve actually built 20+ pedals; 10+ from PedalPCB. This is my first PedalPCB that hasn’t functioned. I think I went into this pedal with a poorly tinned iron, which is why some of the joints look really shady.


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## okstateblues (Oct 24, 2020)

I hear ya. I would start where signal dropped and continue down the that path to see if that cures your ails. If that doesn't work, we can continue troubleshooting


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## marksescon (Feb 10, 2021)

okstateblues said:


> I hear ya. I would start where signal dropped and continue down the that path to see if that cures your ails. If that doesn't work, we can continue troubleshooting


I know this is belated but I actually started from scratch from the new revision, and it works. I truly believe it was my shoddy soldering skills combined with my subpar soldering iron. But thanks for the assistance!


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