SOLVED Texel works for 1 second

[jcpst]

Here’s the problem- when I flip the bypass, it works for a second then quickly fades out. I’m attaching a short audio file that demonstrates this.

I tested all the components before I added them.

If I had to take a guess, it would be on either of the transistors. What I don’t know is what to do about it if that’s the problem, besides just trying out other ones until I found something that worked.

View attachment Texel issue_1.mp3

 

[BuddytheReow]

I'd clean off some of that flux on your board first. Then go through the checklist: is everything powered with correct voltages? Are all your components correct and oriented correctly?

 

[jcpst]

Something is up with the voltage. I’m getting fractions of a volt from the terminals on the power jack.

Just as a sanity check, with the circuit removed from the jack, the jack was getting 9.4V. I inspected for shorts and haven’t found anything yet.

 

[Nostradoomus]

desolder the dc jack and try hooking up the power wires to a stable voltage, sounds like a bad jack (is it a tayda lumberg knockoff?)

 

[jcpst]

Actual lumbergs from Stomp box parts. I tried another, tested the jack by itself, then connected it to the circuit. Same issue.

This issue is a new one for me! I can bypass it as many times and as often as I want. The pedal will pass sound and the controls seem to behave right, but it will just fade out right away.

 

[Nostradoomus]

That is bizarro! What kinda jfet is in there?

 

[swelchy]

my bet is the footswitch daughterboard... Could have a weird piece of leftover wire lead in between stuff or possible solder bridge... .Thats why I just never use them because i'm heavy handed with the solder already...

 

[jwin615]

Cap in the power section is either reversed or bad

 

[jcpst]

That is bizarro! What kinda jfet is in there?

2N5457. From stomp box parts- I was going to try my other one but of course I just lost it. I socketed both transistors and then tried some others with the same result.

my bet is the footswitch daughterboard... Could have a weird piece of leftover wire lead in between stuff or possible solder bridge... .Thats why I just never use them because i'm heavy handed with the solder already...

Cap in the power section is either reversed or bad

Caps appear to be oriented correctly. Since caps are cheap and easier to replace I probably try that first

 

[jcpst]

Just for everyone’s entertainment at my expense, I found that other jfet… right where I left it

 

[Nostradoomus]

well that answers my next question, did you measure the vp

 

[jcpst]

tested new caps and added them, gave the board an extra alcohol scrub, tried the other JFET. Still the same results.

I gotta leave the bench for the night, but I think the next thing I’ll try is a switch w/o the breakout.

 

[Robert]

I'm not familiar with this layout but I don't see an onboard LED, which makes me wonder if those -/+ pads at the bottom of the board are raw VCC and not the low side of an LED/CLR...

And if that's the case, the breakout board is shorting your 9V supply to ground when the pedal is active.

 

[DailyDovetails]

I'm not familiar with this layout but I don't see an onboard LED, which makes me wonder if those -/+ pads at the bottom of the board are raw VCC and not the low side of an LED/CLR...

And if that's the case, the breakout board is shorting your 9V supply to ground when the pedal is active.

Looking at the trace that appears to be what’s happening.

 

[jcpst]

I'm not familiar with this layout but I don't see an onboard LED, which makes me wonder if those -/+ pads at the bottom of the board are raw VCC and not the low side of an LED/CLR...

And if that's the case, the breakout board is shorting your 9V supply to ground when the pedal is active.

Yep! I recycled the case- the faceplate went over the LED hole- I decided “meh I don’t need an LED” and then didn’t think anything of it.

Thanks Robert!