Late 70's Big Muff Pi with clean blend

[azrael]

I used a GGG PCB for this. It's pretty much to Late 70's specs, some alterations here and there. Using the Buff N' Blend (BnB) for my clean blend, on perf.
Anyway, I plugged it in today, bypasses fine, which is good...but then when I switch the effect on, it's exactly the same! It's still clean.
Moving the clean knob back all the way back seems to either reduce the volume/output or scoop the mids - either way, it drops the perceived volume of the signal.
There's absolutely no distortion happening here at all!

I'm fairly sure I wired it all properly...The BMP's IN and OUT connections are connected to the BnB's FX IN/OUT, and the BnB's are connected to the jack and switch. The ground connection of the BnB is connected to the same point as the BMP's grounds.

I've got to go to work in a bit, but when I get back, I'm going to remove the Buff N' Blend from the circuit, to try and isolate the problem.

Any thoughts as to what's going on?

[Solidhex]

Yo

  You should build yourself an audio probe. You could check to see (hear) if the signal is routed properly and where the mistake is. Its sort of a hard thing to debug without seeing a pic. Put a link up for both the circuits too as I'm too lazy to do searches for them haha.

--Brad

[azrael]

An audio probe? What's that? I have a multimeter - I was going to check the voltages when I got home from work (still here...) or tomorrow morning.

Here's the BMP schem:
http://www.generalguitargadgets.com/pdf/ggg_bmp_l70_sc.pdf

And here's the diagram I used to do the Buff N' Blend:
http://www.aronnelson.com/gallery/main.php/v/BarcodeVeroLayouts/album120/buffnblendPCB.gif.html

I'll report what happens when I take the Buff N' Blend out - I have a feeling that may be the problem, doing layouts on perf isn't my strongest DIY skill.

[petemoore]

http://www.diystompboxes.com/pedals/debug.html
   I typed audio probe in google.

[azrael]

Sorry, I didn't have much time to do a lot of surfing when I was at work, just checked a few messages and got off...

Anyway, that looks like a solid method, I'll built the jack version, since I don't have any extra cables I can chop up right now.

[petemoore]

  Audio probe is a good tool, easy to whip one up !

[azrael]

Well, it seems that the BMP PCB is the questionable one. No sound without the Buff N' Blend. Dang.
Well, I'm going to go over the schematic and PCB, making every piece goes to ground/etc...