Wah experts: I built the BYOC and I'm having problems...

[dap9]

Hey guys.  I'm really hoping someone can help me here.  The BYOC guys have been great, but I'm still having the same problem.
Here's what I posted over at Harmony Central as well:

Basically, I bought the PCB and sourced my own parts. I already had a Halo Replica inductor that was in my modded Crybaby and worked fine. Same w/ my Hot Potz II.

The short of it is the wah distorts when I use my bridge pups. I'm not using anything too hot. One guitar has a Seymour Duncan JB/59 combo so the JB's in the bridge. The other guitar has a set of GFS Mean 90s in it. I've gone over all the parts and they're right and the soldering seems good enough. I didn't wire up a DC jack, but I wired up a 9v plug so I could hook up my One Spot w/ an adapter. I'll post a link to my recent thread at the BYOC forum which has a link to my original thread. There's pics there of my board. There's also a recording there.

I appreciate any help that people can offer. I've had my wah off my pedalboard for over 2 months and I'm getting sick of not being able to figure it out. I'm getting ready to put my modded Crybaby board back on. I can't help but think "if it ain't broke..." But I like the BYOC stuff and wanted a little more versatility. (FYI, Keith is the owner of BYOC, that's why the title of the thread has his name in it)

http://board.buildyourownclone.com/viewtopic.php?t=7916

[jakenold]

The key here, is the input resistor (a little fella in the range of 390-470 ohm at the start of the circuit). Hook up a 1K ohm trimmer and tune it to taste. Also, transistors play an important role here. BC107 / BC109 give pretty good results with a HFE around 300-400.

[jonathan perez]

dont forget about the volume resistor. if youve got it around 33k, it can overdrive your amp...

hey jake, hows it goin? 

[Paul Marossy]

The key here, is the input resistor (a little fella in the range of 390-470 ohm at the start of the circuit). Hook up a 1K ohm trimmer and tune it to taste. Also, transistors play an important role here. BC107 / BC109 give pretty good results with a HFE around 300-400.

I know from experience that the transistors are a big factor there. I didn't know about the input resistor, though. Good info to know.

dont forget about the volume resistor. if youve got it around 33k, it can overdrive your amp...

This I did not know, either. 

[dap9]

Thanks guys.  The BYOC PCB has trimmers for Gain, Bass, Mids, Q, and Buffered Volume (for buffer bypass).  So I think the input resistor and whatnot is incorporated in those.  I've tweaked the trimmers every which way and the only way to not get the distortion is to have a ridiculously crappy, low effect. 

I have BC109 trannies in there, which is recommended and still have the problems.  I've also had BC108s which did the same thing.  I had another kind, but I forgot which.  That one really subdued the overall effect.

The marks on the trimmers are NOT the "ideal" settings.  I messed up and measured the 1/2 way mark and put my mark there.  duh.  I'll put pics below.  Thanks for the responses, lemme know if you figure anything else out.

Here's a pic of the board:


And the underside (I resoldered that "Y" pad towards the bottom)

[BDuguay]

Have you tried adjusting the buffer trim? I experienced some problems, with an early wah build, that was caused by having the buffer trim up to high.
B.

[dap9]

Have you tried adjusting the buffer trim? I experienced some problems, with an early wah build, that was caused by having the buffer trim up to high.
B.

Yeah, I tweaked all of the trimmers in all kinds of ways.  It distorts when the buffer isn't bypassed also.  Now I didn't try turning the buffer way down and playing.  I figured that if the volume was that low, you wouldn't be able to hear it anyway.  I guess I'll try that just to see.

[dap9]

Well I tried adjusting the buffer trimmer to no avail.  Whatever is going on happens even at low volumes.  No matter how low I set the amp or my POD, it distorts.  I'll post a link to the pdf file.  The schematic is towards the bottom.  I just don't know enough about what else it could be and I'm getting ready to just throw the whole thing in the garbage and put my modded Crybaby board back in.  Here's the pdf:

http://buildyourownclone.com/wahinstructions.pdf

[Fuzzy-Train]

IDK if this could be the problem... but it looks like you forgot to add the jumper above the range cap. The instructions say to leave it out if you don't want the buffer, but you obviously used the buffer. I'm not sure if that's the problem or not, but it's a simple test.

Don't give up man... you'll get it.

EDIT: never mind I just read the "mods" section. Maybe you should try it without the buffer on/off switch, or without the buffer altogether.

[dap9]

IDK if this could be the problem... but it looks like you forgot to add the jumper above the range cap. The instructions say to leave it out if you don't want the buffer, but you obviously used the buffer. I'm not sure if that's the problem or not, but it's a simple test.

Don't give up man... you'll get it.

EDIT: never mind I just read the "mods" section. Maybe you should try it without the buffer on/off switch, or without the buffer altogether.

Thanks for the encouragement, man.  Problem is, I had this problem BEFORE I did that mod.  I did the mod b/c it was recommended.  I'm not complaining - hey, the more switches, the cooler it looks!

I wonder if one of my pots is bad, or if there's another reistor/cap I should change.  I don't know a lot, but it seems like the signal is just too hot at the input.  Again, thanks for the encouragement, but it's been 2 months!  I might just bite the bullet and get the drop in kit just to see if there's somethign that I missed.  BYOC has been really good to me so I'm not giving up on the company.  But they've stopped selling just the PCBs so I can't just order a new one and start from scratch (b/c I'm wondering if I screwed up the board somehow).

Well, the saga will continue.  Thank god for wine and whiskey!

[dap9]

Bump