SOLVED Woodpecker Tremolo not modulating

[chris.knudson]

I was hoping to post a successful build report tonight, but my Woodpecker Tremolo isn't modulating. I get a good bypass signal, and the pedal powers on and passes signal, but I'm not getting any effect out of it. The Depth and Rate controls don't seem to do anything. The Level works, but I can barely get to unity gain with the level all the way up. I'm guessing that it has to be the transistors, right? I'll try swapping them out tomorrow, but was wondering if anybody else had any ideas.

 

[Robert]

I'm guessing R1 is my problem -- looks like I'm sending too much of my signal to ground right from the get go.

Oh yeah, definitely. Get those values straight and we'll go from there.

 

[jimilee]

My soldering isn't always the prettiest, but I like to make sure that I've got got a good solder joint that flows through the board and connects to the pads on both sides of the board and that I don't have any solder bridges anywhere.

Yep, I go back and do that after I cut the leads just to make sure, as well.

 

[chris.knudson]

Alright, swapped out the resistors, and the volume issue is resolved. She's plenty loud now. Still no modulation. Guess I'll put her back on the bench until I can get a good 2N6027 and go from there. I'm guessing that's my problem.

 

[Robert]

Yep, sounds like that's where you are now.

I'll let you know as soon as it's here.

 

[chris.knudson]

Yep, sounds like that's where you are now

Going to get back to this one this weekend, but first I have some minor surgery to do. I have to remove 2 of the transistor sockets. On one, the machined part pulled out of the middle when I removed one of the bad transistors, and on the other one, one of the transistor legs snapped off, and I can't get it out of the socket. I probably fiddled with it too much when I was troubleshooting. I'll get it cleaned up and let you know if the new transistors did the trick.

 

[chris.knudson]

Ok, progress update... I've made no progress . I managed to desolder the sockets -- installed new ones. Then I installed all new transistors (all known good ones -- at least they came from authorized dealers). I tested the pedal, and now I only get bypass sound. I was getting sound through the board before, but now nothing. I reflowed all the solder joints, and I even re-soldered a new level pot thinking I may have cracked the legs when I bent it over to replace the sockets. And still nothing. I think I've reached my limit of frustration for one weekend. I may try to probe the thing tomorrow, or I might just buy another PCB and start over. I hate to give up, but this one has me stumped.

 

[VanWhy]

Ok, progress update... I've made no progress . I managed to desolder the sockets -- installed new ones. Then I installed all new transistors (all known good ones -- at least they came from authorized dealers). I tested the pedal, and now I only get bypass sound. I was getting sound through the board before, but now nothing. I reflowed all the solder joints, and I even re-soldered a new level pot thinking I may have cracked the legs when I bent it over to replace the sockets. And still nothing. I think I've reached my limit of frustration for one weekend. I may try to probe the thing tomorrow, or I might just buy another PCB and start over. I hate to give up, but this one has me stumped.

Any more updates with this? I built one and the same thing. Just a boosted signal but no tremolo. I tried all of my 2N6027 and a bunch of 2N5089.

 

[chris.knudson]

No, not yet. In all of the fiddling with it, I have managed to break something, but I haven't been able to figure out what the problem is. I need to probe it, but I've been too busy playing bass, trying to learn a bunch of new songs before my next band practice. I have a tone generator on my workbench right now, and I hope to get that built so that I can play with it when I go to probe the pedal -- probably this coming weekend before I'll get back to it.

 

[chris.knudson]

Finally got back to this one. Basically I started over on it. After I pulled the bad sockets out of the other one, I broke something else in the process. So I built another one but with legit transistors from Mouser, and it works fine now.

 

[chris.knudson]

Any more updates with this? I built one and the same thing. Just a boosted signal but no tremolo. I tried all of my 2N6027 and a bunch of 2N5089.

Not sure which one fixed the problem, but I replaced them both and it works fine now. I don't know about the 2N6027, but I'm pretty sure my 2N5089's were all fakes. I used one in another pedal that isn't working either. I bought a bunch of them from Mouser, and I decided that whenever possible, I am only going to buy branded transistors from authorized dealers from now on.

 

[VanWhy]

Not sure which one fixed the problem, but I replaced them both and it works fine now. I don't know about the 2N6027, but I'm pretty sure my 2N5089's were all fakes. I used one in another pedal that isn't working either. I bought a bunch of them from Mouser, and I decided that whenever possible, I am only going to buy branded transistors from authorized dealers from now on.

Thanks for responding. What worked for me was new 2N6027 from Mouser. I had some bogus ones from Amazon go figure.

 

[chris.knudson]

I had some bogus ones from Amazon go figure.

Yeah, I'm down to just buying resistors from Amazon, and even those are suspect. I've had some 1% resistors register as much as 5% off spec. I used to love Amazon for parts, but there are way tooo many counterfeit and bogus parts for me to trust Amazon anymore.