"Groble" green ringer debugging

[Jmsteele187]

I put together a modified version of a green ringer, using this schematic and layout, but it's not working.  Here's the link: http://www.tdpri.com/forum/burnt-fingers-diy-effects/326950-groble-green-ringer-octave-blend.html
The LED's light up, but there's very low output, and the signal sounds unaffected, and a little microphonic.  I couldn't fit a battery in the enclosure, so I've only used a power supply, that I know is good.  I took these voltage readings.
Q1, E 1.26, B 1.83, C 5.36 Q2, E 5.97, B 5.36, C 3.4  Q3 E 3.87, B 4.4, C 9.41
IC1 1: 4.7 2: 4.7 3: 4.39 4: 0 5: 4.7 6: 4.7 7: 4.7 8: 9.41
IC2 1: 0 2: 0 3: 0 4: 0 5: 4.69 6: 4.17 7: .96 8: .43

Any help would be greatly appreciated.

[slacker]

IC2 isn't getting any power, pin 8 should be 9 volts. Did you follow the "IMPORTANT" note?

[Jmsteele187]

Oops. Nope, I totally forgot about that.  I'll fix that and see what happens.

[LightSoundGeometry]

im an octavio freak , so I will probably attempt this build. soon!

so cut pin off IC number 1 and no track cut ..sounds easy enough..i think i am going to bypass the octave blend and just leave the octave always on like the options show that you can

[Jmsteele187]

I jumpered the trace that I wasn't supposed to cut, but did.  Now there's no sound at all, when the effect is on.
The new voltages for IC2
1: 1.32
2: 1.71
3: 1.40
4: 0
5: 4.7
6: 4.71
7: 4.73
8: 9.41

[Jmsteele187]

So, I thought I'd give this circuit another try.  So I built the board again, all over from scratch.  Unfortunately, I'm getting pretty much the same results.  It's not working properly.  I did make sure that I didn't make the same mistakes I mentioned above.  I decided to re-read the original thread, where I found the circuit. (The link is above)  After reading through all the replies, the op suggests adding in a buffer.  Could this be my issue?  I'll take voltage measurements later, when I'm home from work.

[Jmsteele187]

Here are my voltage readings:
Q1 C:5.29 B:1.85 E:1.29
Q2 C:3.55 B:5.29 E:5.91
Q3 C:9.41 B:4.41 E:3.88
IC1
1: 8.52
2: 8.53
3: 1.45
4: 0
5: 1.56
6: 1.44
7: 1.44
8: 9.41
IC2
1: 1.37
2: 1.07
3: 1.09
4: 0
5: 1.56
6: 1.48
7: 1.45
8: 9.41
If this helps anyone see a problem, I'd love to know what you think.  Thanks.

[PRR]

It's already well buffered.

I'd realy be looking for missing grounds, bad solder joints, rotated switch, bad jacks.

What is the DC voltage on VR (C5)? It should be half supply. I'm not sure which chip pin is which but I'm not seeing 4.5V anywhere.

Build a signal tracer. Should be signal at the input switch, same at C1. Louder at Q1 C and Q2 C and E. Dynamic octave distortion at Q3 B and E. If you get that far, try jumping C10 to a temporary output jack and play. It won't have fuzz or tone-knob, but at least you can prove most of it works.

[Jmsteele187]

Thanks for the advice, PRR!  I'll check everything the next chance I get.

I assume by "signal tracer" you're talking about an audio probe by any other name?  It's been on my list of to do's for the last couple weeks.  It seems like a very useful tool.

[Jmsteele187]

Well, everything works through C10.  So I guess I know most of it is working.  I'll try to trace the signal from there, and hope I can figure this out.

[Jmsteele187]

I've been trying to follow the schematic, and layout to figure out where to try to trace the signal next.  But, I think I'm getting even more confused.  I checked for output at the output cap (C14) and get nothing.  I believe I need to check C9 & C12 next, but not quite sure.  If I get nothing at C9, I know there's something going on with the blend control, that's not right.  And if I get nothing at C12, I would assume something isn't right with the overdrive circuit that follows. 
In looking at both the schematic and the layout, I found things that raise more questions.  Like the lack of diodes in the layout.  The schem shows one in the power section, two in the octave section, and another in the clipping section.  But, the layout only has three diodes in total.  Am I missing something here?

[slacker]

The diodes are all there but it's not obvious looking at the layout. D2 and D3 on the schematic are the thing that looks a bit like a jumper right next to pins 6 and 7 of IC1 on the layout, whoever did the layout has jammed both the diodes into one hole at each end. You can just about see it on the "guts" photo. If you have put a jumper in that spot then you'll get no sound out of the overdrive stage.

[Jmsteele187]

The diodes are all there but it's not obvious looking at the layout. D2 and D3 on the schematic are the thing that looks a bit like a jumper right next to pins 6 and 7 of IC1 on the layout, whoever did the layout has jammed both the diodes into one hole at each end. You can just about see it on the "guts" photo. If you have put a jumper in that spot then you'll get no sound out of the overdrive stage.

At first I was like, what is slacker talking about?  Then I saw it.  Yes, I do have a jumper there, because that's what it shows on the layout.  I'll pull the jumper, throw in a couple diodes, and see what happens.  I wondered why he jumpered the inverting input to the output on that second stage of IC1.  It didn't make a lot of sense to me, now I know why.  Thanks slacker.  I'll report back with my progress.

[Jmsteele187]

And I still have nothing.  I wish I had more time to mess with this project.  I'll do some probing tomorrow.  If anyone has some other ideas, I'm certainly open to them.  I've gotten some great info so far.  Thank you.

[Jmsteele187]

I shouldn't say I don't get anything.  I do get a very weak, unaffected signal.  The who pedal seems.... microphonic?.... That's the only word I can think of to describe it.  Every little bump of the pedal comes through the speakers and will start to feedback.