Big Jerk (another debug thread)

[mistahead]

I've been working on a slightly "hacked together" combination of Tim E's Utility Boost driving into his Harmonic Jerkulator and then out through the Guv'nor tonestack... so far working pretty well with a couple of interesting quirks that I'm sure I'd have foreseen if I'd left this project off the table for another year - so specifics in case anyone can offer advice.

For the boost and the Jerk I've linked them at 9v+, input to the boost, output to the jerk, jerk out to amp with a common linking of GND's, all is well EXCEPT (and I'll bet someone will guess this) when the gain on the jerk is dialled down the circuit "sirens" - I'm guessing it is a grounding issue but the specifics are eluding me. I currently don't have a volume divider at the back of the jerk as I intend to put the wet signal direct into the tonestack and let it control shape and volume.

The other issue is that when using this vero for the gov's tonestack:
http://www.aronnelson.com/gallery/main.php/v/mr_adambeck/vero/guvnortone2.jpg.html
Probing backwards from output it falls down around C14, DMM on that connection and I don't seem to be able to get a reading for capacitance on it nor any value for resitance (at all, even vero strips have some that I can get) - seems pretty obvious that I've either dodgy cap or stuffed the solder right? I ought to be able to place a DMM along the cap and get SOME resistance (even of nil) reading rather than looking like an open circuit yes?

Pickup up knowledge at a quick rate here so any clarification or tips of what I've done wrong will only help there.

[mistahead]

Ok - it occurs to me that I ask poor questions... going over this in my head I really wanted to ask two very specific questions and wasn't really that eleoquent in doing so...

1. If you're linking effects that don't share a common vero/pcb and pull the post/gnd power together, is there as oscillation/noise issue when dropping a pots to zero - the Harmonic Jerkulator here may be a special case as it might end up with the input signal being swung way out to ground... is there something I'm missing?
EDIT: It is acting as a voltage divider at the input... I suspect I could resolve this by dropping a resistor across the P1-P3 portion of the gain knob (I've below linked the vero) - question is really I suppose coming to me now - what value resistor would suit (higher is my feeling - but how high?) or is a cap somehow the better option?
http://www.aronnelson.com/gallery/main.php/v/DRAGONFLY-LAYOUTS_0/album17/album06/HARMONIC_JERKULATOR.jpg.html

2. Even if in a circuit I should expect caps to display current through them as well as a capacitance value if I measure with a DMM... right? If I click through my DMM's Ohm bands and am getting 100% restistance across every range it most likely would indicate bad solder or otherwise trashed capacitor is my feeling - can this be confirmed?
EDIT: I'm sure I've got an open circuit situation on the C14 mentioned previously - but now I'm becoming curious as to how a .1uf or .05uf cap would go in that position... hehehe.

[waltk]

2. Even if in a circuit I should expect caps to display current through them as well as a capacitance value if I measure with a DMM... right? If I click through my DMM's Ohm bands and am getting 100% restistance across every range it most likely would indicate bad solder or otherwise trashed capacitor is my feeling - can this be confirmed?

Nope.  If I understand you correctly, you're thinking you can measure DC resistance through a cap?  Caps do not pass DC at all.  If you see anything but 100% resistance, the cap would be bad.

[mistahead]

Excellent... I can still track the break-down to there, its a cheap enough part to replace and see how it goes and take it from there anyway - thanks for the info (back to basics again, cap's and pot's today!).

And on the first issue - I've worked out that it is occuring when I open the booster into the H.J. with the gain sitting on the GND end only, basically I've just have to work out what I need to put across the pot to ensure that it doesn't "bottom out" and start the "sirens" on me - hence the pot theory, bumping up the resistor to ground I doubt will help and I can live with affecting the "swing" of the gain values...