Electra Distortion troubleshooting

[nchauhan890]

I've been making my first pedal build - a modified version of the Electra Distortion and have encountered a problem right after boxing it up. I had tested jy it on breadboard, outside of box and at first when I boxed it: it worked at those 3 stages.

Here's the troubleshooting info:

1. It works fine when bypassed, but whenever turned on I get no output however the LED turns on
2. Electra Distortion (modified)
3.

https://postimg.cc/image/wo4gimrl7/
If you can't see it, it's what I found at diyguitarpedals.com.au as 10 min boost/dirt. I added a blend mod found on the AMZ effects page called saturation control.
4. Yes I modified the original and the picture above is what I used
5. Input/output caps changed to 2.2uF and the low pass at the end used 10n cap + 39k resistor
6. Negative ground
7. Voltage readings...
Battery: 9.89
Transistor 2n3904...
- base: 0.96
- collector through 3k3 to 9V: 8.09
- emitter to ground: 0.37

Please ask for any pictures as necessary. I'm fairly certain the in/out/dc jacks are fine and so is the 3pdt as the bypass and LED works. I don't think my pots are inadvertently grounded since my enclosure is plastic.

[stringsthings]

Excellent choice for your first build.

If it worked on the breadboard and outside of the box, then logically, the problem occurred in the boxing up phase.
Verify that power is getting to your build and your grounds are o.k.
Use your DMM on the continuity function to double check the inputs/outputs to and from the PCB/vero/perf to and from the 3PDT,
to and from the input/output jacks, etc. 

If things worked when you first boxed it up and then it went out, you may have a dodgy solder joint somewhere.
Check that all your offboard wires are making solid, shiny connections to where they're supposed to go.
Offboard wiring is a typical place for problems to occur.  The more wires, the more chances for probs.

And welcome to pedal DIY!  Are you building this for bass? 

( pics would be nice )

[nchauhan890]

As a mater of fact, yes, I am building for bass.
Update: I've managed to track down the problem and have done a temporary fix. The circuit itself is fine, but it seems like the volume pot is dodgy. I replaced on of the wires and the problem persisted. My multimeter shows all the connections are made. My only solution at the moment is to push down a wire and for some reason it works. I've put in a blob of sticky tack to hold it down for now.






Tried to make the wiring as neat as possible... Perfectionist.... it's solid core wire so pretty sturdy but I don't want to put too much strain/movement on them.



(If you look at the bottom picture, the volume pot is the top-left one.) That red wire connecting the two pots I've replaced and with no difference. That's the wire that needs pushing down, by the way.

It's really frustrating to have a temporary fix and that all my connections are seemingly fine.
Also... None of my connections are fully shiny but are decent. The great shine seems to oxidise over as soon as I remove the soldering iron leaving a semi-shine.

[stringsthings]

Good work on tracking down the problem.
Pot issues are a pain.  Especially when they're intermittent.
Wiring looks great.  Neater than mine.  Solder joints look good.

I try to keep spare pots around. Even if just for testing. 

[nchauhan890]

Would you have any advice about what I could do to try and fix the issue? I just find it really weird that a small wire movement could do this. Especially since it's a fresh wire.

[stringsthings]

Would you have any advice about what I could do to try and fix the issue? I just find it really weird that a small wire movement could do this. Especially since it's a fresh wire.

I'd just replace the pot.  In my experience, it's not worth trying to fix a dodgy pot.  For one reason, you never know if it's going to fail in the future.
A replacement is peace of mind.  In some cases, excess heat from leaving the soldering tip on the lug too long, can lead to damage. Also, heat damage on switches
is not uncommon.

[nchauhan890]

Thanks, I'll have to see where I can find a pot locally now as I don't want to spend money on shipping for only a single pot. And our Maplin (in the UK) has gone out of business...

[stringsthings]

You might try Arrow here in the U.S.  Every once in a while, they have free shipping.
I think it applies to overseas, but I'm not sure.  They're selection isn't as big as Mouser/Digikey,
but I use them for when I need one or two parts. 

I just ordered 10 resistors for 50 cents, and it's supposed to be here tomorrow.

[bluebunny]

Thanks, I'll have to see where I can find a pot locally now as I don't want to spend money on shipping for only a single pot. And our Maplin (in the UK) has gone out of business...

I'm sure this won't be the only thing you'll build (ask me how I know...), so why not stock up a little?  Check out Bitsbox if you want somewhere local, or Tayda (discount coupons pop up often).

[thermionix]

Solid core wire is more prone to breaking than stranded, and you won't know it if the break is inside the insulation.  Not saying that's your problem, but surely could be if the wire is intermittant when pushed.