First time question. Okay...questions.

[Flounder]

First, thanks for all the info you guys provide everyday!

Now, I've built a few successful simple pedals from designs off this site, but this one has been kicking my butt.  I figured I would see if anyone else has tried it before I further troubleshoot.  It's the modded Rust Driver from MarkMs gallery:
http://www.aronnelson.com/gallery/main.php/v/MarkMs-Gallery/album15/album76/HAO_RustDriverMOD_pnp.gif.html
http://www.aronnelson.com/gallery/main.php/v/MarkMs-Gallery/album15/album76/HAO_RustDriverMOD_layout.gif.html

1) Has anyone here tried/verified the pcb?  It looks right to me, but I simply can't get it to work.  I can get the circuit to work on the breadboard, but there's no output when I use the pcb.  I even made another pcb, with good parts that also worked on the breadboard, and same issue.

2) The Crash sync.  Anyone remember this?  I just built one, and I love it.  However, I'm pretty sure somethings not 100%.  the layout refers to the 100k pot as "Depth".  Mine acts as a volume, and the circuit is EXTREMELY loud.  I can control it to a usable level, but only if I turn the part maybe 1/4 up.  the pedal sounds good, but this seems wrong.

Thanks again
Ryan

[petemoore]

  Easier for me to tell from a schematic.
  R1, R4,  look like one end is floating...
  I tried to identify a voltage divider circuit...I'm not sure it has one.
 
 

[oskar]

No. R1 and R2 form a voltage divider. The layout looks OK.

I found this schematic. All components values are the same except R3 which is 1n2 in the schematic
and 12n on MarkM's layout. Plus the layout also has the gain pot.

Check the sticky "What to do when it doesn't work" and post voltages as described in there. But first off course build yourself an audioprobe and (also in that link), so you can follow the signal and find out where it goies dead.
One thing that would kill the signal is if the output and the inverting input is shorted, either by a solder bridge or by shorted components. Last time I experienced this in a troubleshoot at this forum it was a failing germanium diode.


ps. Welcome!



Oskar

[markm]

I built one from the layout in the gallery just to verify it before posting and.......it worked.

[Flounder]

Thanks for the responses.  I too built it from the layout, and it worked 100% on the breadboard. I can't get it to work on the pcb though.  I even etched 2 boards and can't get either to work.  I'll put an audio probe together later and start checking the board.  Thanks again.

[Flounder]

Ok.  The audio probe works once again.  Evidently there was a bad connection or solder bridge at the pin2/330k/100k connection.  I couldn't see anything, even with a magnifying glass.  What's really sad is that I had the same issue on 2 pcb's.  That's where the audio stopped though, and once I unsoldered/soldered, I had output.  It doesn't seem to have the gain it did when I bread boarded it, but I may just be imagining things.

My other question still stands though, for those who still have a Crash Sync or remember it: The layout refers to the 100k pot as "Depth".  Mine acts as a volume, and the circuit is EXTREMELY loud.  I can control it to a usable level, but only if I turn the pot maybe 1/4 up.  The pedal sounds good, but this seems wrong.  Is this right, or do I truly have an error somewhere?    I searched and found one other post that mentioned his acting as a volume control, but there was no detail.

This was the layout I used.  http://www.hollis.co.uk/john/crashsynclyt.jpg  My only substitutions were a B100k for the trim pot and a 4558 for the TL072.

Thanks