Debugging TS9 with clipping switch

[litstalov]

Hi everyone. I've built a TS9 clone but it's not working. Actually, I've built it twice, and both times not working... I couldn't find any mistake in my first build and I measured dc voltages and nothing seemed wrong, so I built the second one with a new stripboard but with the same parts, but no luck.

Following Aron Nelson's suggestion on debugging (http://www.diystompboxes.com/smfforum/index.php?topic=29816.0), here is the information a gathered. I'm going crazy with this one (I know, not being calm is my worst enemy!), so please, please, shed some light on me.
Thanks in advance. César.

1.What does it do, not do, and sound like?
It seems that everything works the way it should (level, gain and tone), but really, really low volume. Well, the gain pot does not actually distort the sound when all the way up, but increases the intensity of the sound. Tone really seems ok, and the sweep in the volume pot seems also ok. But everything is very low and undistorted.

2.Name of the circuit
Ibanez TS9 compact with clipping switch (from tagboardeffects)

3.Source of the circuit (URL of schematic or project)
http://tagboardeffects.blogspot.pt/2012/02/ibanez-ts9_17.html (second image)

4.Any modifications to the circuit?
No

5.Any parts substitutions?
No

6.Positive ground to negative ground conversion?
No

7. What is the out of circuit battery voltage?
9.08

Report the voltages as follows:

Q1
C = 9.08
B = 4.60
E = 4.02

Q2
C= 9.08
B= 4.60
E= 4.03

IC
P1: 4.70
P2: 4.70
P3: 4.55
P4: 0
P5: 4.64
P6: 4.65
P7: 4.65
P8: 9.07

D1
A (anode, the non-band end) = 4.53
K (cathode, the banded end) = 4.60

D2
A (anode, the non-band end) = 4.61
K (cathode, the banded end) = 4.53

Voltage at output of PCB: 0
(don't know if this last one is relevant or not.)

[GibsonGM]

Make an AUDIO PROBE (use the search function).  It is just a patch cord plugged into your amp, and the business end you attach to the circuit ground, and use the tip (inner core wire) to probe your circuit (on pretty low amp volume!).

You can go thru from input to output and see if there is a decrease in vol. somewhere, possibly indicating a short, bad solder connection, etc.  EXTREMELY useful piece of homebrew equip - I used an old meter probe on mine, and a jack....I'm not seeing 'bad' voltages on your stuff, BTW...

Actually, here, go to this link, build one, and report back!  At least the TS WORKS, just has a bug. You'll find it! 
http://www.diystompboxes.com/pedals/debug.html

[litstalov]

Make an AUDIO PROBE (use the search function).  It is just a patch cord plugged into your amp, and the business end you attach to the circuit ground, and use the tip (inner core wire) to probe your circuit (on pretty low amp volume!).

You can go thru from input to output and see if there is a decrease in vol. somewhere, possibly indicating a short, bad solder connection, etc.  EXTREMELY useful piece of homebrew equip - I used an old meter probe on mine, and a jack....I'm not seeing 'bad' voltages on your stuff, BTW...

Actually, here, go to this link, build one, and report back!  At least the TS WORKS, just has a bug. You'll find it!  
http://www.diystompboxes.com/pedals/debug.html

Hi! Thanks for the suggestion. I've already built a probe but I'm not shure I'm using it correctly. I probed this build and I can hear sound both on the input and on the output of the PCB. It seems to be the same volume, a low volume. My questions are: is the sound picked up by the probe suposed to be as loud as the normal output of the effect is expected? If when probing input and output of PCB I hear more or less the same, is it still necessary to probe "inside" de circuit? What path should I follow when probing? Current or signal from instrument? (probably a dumb question...)

[LucifersTrip]

My questions are: is the sound picked up by the probe suposed to be as loud as the normal output of the effect is expected?

probably not...the vol will prob change after each stage or filter

If when probing input and output of PCB I hear more or less the same, is it still necessary to probe "inside" de circuit?

you could possibly have the normal clean at input, amplification somewhere in the middle, then signal killed later, so yeah, always good to check....

What path should I follow when probing? Current or signal from instrument? (probably a dumb question...)

the audio path...check after each stage. schematic will be needed:

http://www.muzique.com/schem/ts808.gif

[litstalov]

I'll do that latter this evening. Is this the relevant signal path I should probe?

[Ice-9]

Sorry posted in wrong post

[GibsonGM]

Here dude, the thick black line is the "main" audio path.  But the other opamp inputs - the feedback loops which set gain, and have diodes for clipping, caps for tone shaping -  have signal, too, and could have shorts, etc, so listen to them as well!    I mean the areas around the "Drive" and "Tone" controls.