Build Your Own Clone Message Board

Hey, I'm quite stumped when it comes to getting my wah pedal working consistently. I've been dealing with this problem for many months and can't seem to figure it out.

Problem: The wah effect of the pedal intermittently stops working but I continue to get a guitar signal through the amp. The wah effect will then start to work again after I rock the pedal enclosure back and forth for a while. Then it stops working again and I continue to get a guitar signal through the amp. The pedal works totally normal when in true bypass mode.

What I did: I checked my momentary switch and solder joints with a DMM and they all seem to be fine.

What I noticed: When I unscrew and lift the board out of the wah enclosure, the pedal seems to work consistently fine, even when I rock it back and forth really hard. I suspect that the wah pedal is intermittently shorting out when it's board is screwed down to the wah enclosure. Because of all the switches I have connected to the pedal's board, there are a lot of wires under that board itself. In addition, when I touch some of the wires on the board, particularly those near the boards in and out joints, I hear a pop and then the pedal starts working again, but only for a short while. Sometimes the pedal will not be working, I turn it upside down and it starts working again.

The 'out' joint on the board looks pretty bad but I've checked it with my DMM and it seems to be working fine. I've tried resolving this problem for so long that I can't count how many times I've soldered and unsoldered that joint, hence it's dirty look. It also has a drop of hot glue on it, which makes it look worse than it really is.

The reason you don't see a 3DPT switch is because I installed a momentary switch onto the pedal, which I've double checked with a DMM and it seems to be working fine.

Any advice on how to successfully diagnose and solve this problem would be greatly appreciated. Like I said, I've been trying to resolve this problem for months and can't seem to figure it out.

You didn’t include the most important thing of all. Shots of the stomp-less switch and it’s wiring.

You could get a set of test leads and make the necessary connections with them on the stomp-less switch to see if the wah effect works and continues to work as you work the treadle. If that checks out there is a problem with the stomp-less switch. Maybe it is on the verge of failing completely or maybe your foot isn’t maintaining constant pressure on the switch’s plunger causing it to make and break the connections as you rock the treadle.

Another option would be to install a normal stomp switch along with the stomp-less switch bypass switch so you can switch between the two bypass switches for instances like this.

Man… that’s a LOT of switching.


OR

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"It’s your soldering."

Could it be that something is shorting off the enclosure, as the pedal works fine when the board is unscrewed from the enclosure?

Maybe... maybe not. You'll have to check that for yourself.

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"It’s your soldering."

Well, I lifted the board off the enclosure and lined the bottom of the enclosure with electric tape. When I put the pedal back together, it worked for a few minutes then stopped.

Is there a diagram or link that shows me how to measure the necessary connections with a set of test leads in order to determine if the momentary switch is dead? What would I be looking for with these test leads and how would I hook them up?

I'm definitely pressing down on the switch enough when using the pedal. I've been very cognizant of that so as to not to overlook it.

Would using an audio probe or DMM help me to isolate the problem? I'm assuming that the necessary steps for using an audio probe are to turn the pedal on, activate the wah effect, and then trace the circuit path using the audio probe. If I get sound from the probe then that component is good. If I don't get sound, then there lies the problem component or joint?

The test leads aren’t used for taking any measurements. Use them to make the connections on the switch that would be made if you were actuating the switch. When you do the test, be sure to press the switch so that the bypass connections aren’t being made. With the jumpers attached and the switch actuated, rock the treadle to see if the wah effect remains constant. If it does you know that it’s the switch itself that is making intermittent contact when used without the jumpers.

I doubt that you have a component problem. I’m thinking it’s a connection problem somewhere.

Still would like to see a shot of the switch and it’s connections.

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"It’s your soldering."

Do the test leads essentially test the effectiveness of the wires that go from the switch to the board and jacks? Is the purpose of the test leads to rule out a broken wire?

Here's the rest of the photos:

No, they’re used to determine if the switch’s internal contacts are going bad or not. You aren’t using the leads to connect the switch to the PCB. You’re using them to hardwire the switch’s internal connections (pole to throw). You need to press the switch’s plunger though to break it’s internal bypass connections.

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"It’s your soldering."

Ok, that makes sense. Is there a link or diagram to show me how to do that properly? Would I have to de-solder all the wires from the switch first?

Are these the connections that I'm suppose to make?

Connect my input jack tip to the pcb in, and the pcb out to the output jack tip, while making sure that the momentary switch is activated.

Time to use that bump between your shoulders. If I spoon feed every little detail to you you’ll never learn anything.

Below is a shot of the stomp switch. It has two columns of three solder lugs each. On the side of the switch the top row of lugs are labeled N.C., the middle row lugs are labeled N.O. and the bottom row labeled C. When in bypass mode there is continuity between the N.C. and C. lugs top to bottom. When you depress the switch’s plunger what happens to the internal connections of the lugs and what would you need to do with the jumpers to replicate the internal connections when the plunger is depressed?

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"It’s your soldering."

Ok, I finally figured this problem out a few months ago but am finally getting around to posting about it now. Just been super busy with two little kids and a wife in grad school. Anyway, the basic problem appeared to be that I wired the 'in' joint on the board so many times that it started to lose its connection. I ended up drilling some of the board out with dremel tool and then re-soldering it. Seems to be working fine now