Probably a simple noob problem (Jordan Bosstone)

[cliffmustard]

Hi all,

I have recently started building some effects projects and had reasonable success although seem to get a problem every now and then that I can't solve.  This has most recently happened with a Jordan Bosstone vero circuit 9 (http://www.aronnelson.com/gallery/main.php/v/Richard-Boop-RLBJR65/album69/jordanbosstone.gif.html).

The pedal is fine in bypass although when engaged I have no sound.  I used a probe and have signal up to the input of C1 (0.022) but no input out of C1.  The circuit has some slight variations 0.022uf instead of 0.02uf (C1, C2, C4) and 47pf instead of 50pf (C3).

I have checked transistor and diode orientation, layout and checked the C1 outside of the circuit.

I have had this issue at the input with a few circuits featuring 2 transistors.  Any pointers would be much much appreciated.

Many thanks,

Cliff

[cliffmustard]

I will add, I did read the debugging article and can post all of the voltages. Just wondered whether this is an obvious problem.
Thanks,
Cliff

[jacobyjd]

If you're not hearing anything after C1, something's either up with the other side of the connection--it's unlikely that it's the cap itself. You'll probably want to post voltages--that'll tell us if anything is grounded that shouldn't be.

[cliffmustard]

Thanks, will do

[oldrocker]

Use a continuity meter and see if you're grounded after C1.  There's a junction on the other side of C1.  There's a 150k to ground and 560k that connects to the emiter of Q2.  The third junction from between the two resistors goes to the base of Q1.  So check if the base of Q1 is grounded too.  It's most likely something that simple.  Make sure that red square with dot in the middle of the board is cut all the way through.   That's a potential ground error.  It's in the middle second trace line up from the bottom.

[cliffmustard]

Many thanks, here are some voltages:

power at board 9.3v

q1
c 0
b 0.63
e 5m

q2
e 0.64
b 0
c 0

D1 0
D2 0

out of R1 0.64

Just checking continuity, will post shortly.  Thanks again.

[jacobyjd]

yeah--those transistors should have much higher voltages. Check to see if something's grounding out (both input and 9v), and also make sure that your power connections are good.

[cliffmustard]

Oops, meant that the voltage out of R6 was 0.64v.