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This is actually my 2nd build. I put together succesfulla a germanium fuzz face clone and I wanted to continue in fuzzy style but adding the octaves...the kit seemed perfect in terms of taste, now I realized a little less perfect in terms of my knowhow to put it together
Probed C27...I have the muffled sound on both pins..
Gave another try re-soldering the IC12 base and I found again the wave (whw IC12 removed), vhen installed music can be heard only on pin2 of IC11, the other have the same whistle as before.

...as you suggested..I will probably put it in a drawer, learn a few more things in electronics ant the maybe someday reopen itand succesfully fix it. Its  frustrating at this time.

thanks for all the assistance. Will stay in touch

best regards,

Alex

Probing D16 cathode the speaker of my amp plays a fuzzy and bright octave effect...as you said.
Problem is the input signal on IC11/p3...signal voltage = 3.54v but the sound comes out in form of a perceptible static whistle (my 9V adapter emits this sound usually when attached to my other mooer pedal.) ...
and I agree it is probably just a cold joint somewhere before IC12...er else?...which part of the diagram comes prior IC12 and it is key? For example: The whistle is heard on both pins 6 and 7 of IC12..one louder, the other almost mute but still a whistle, no music...should I check the joints of components from D16 or other directions?...feel a bit lost. It has become such a tought maze for me to resolve...It is definitely not a project for greeners like me

My second guess would be a faulty 150p cap on C30 position...one pin has 8.99V and the other 0.00. burned???

Hi Scruffie.

Spent a few hours during weekend doin some testing and probing...
I am clueless except for onbe thing...while probing around diode n16 I noticed that there is sound on the + pole but a static whistle on the opposite side...same whistl  can be heard on IC11/p7 and IC12.
Could that be a faulty diode causing the issue? It is right before the IC12 or am I wrong?

ty,

Alex

The trem effect occurs while playing guitar without the ic12...wasnt probing...just tried it plugged normally. On off time does not change by playing...like a tremolo effect all the time when the pedal engaged.

Hmm..playing without the ic12 does not change the pitch. The effect souds like a vibrato. 

Hi Scruffie me again.
I removed temporarily all the sensitive components and did a reflow on some suspicious pin joints of IC13 and IC11...Still no change in Subharm function.
I tried replacing both IC13 and the LM311 with new components from the local electronix shop. Done probing each component after IC12 ...just jacked in my pc with some easy acoustic guitar riffs, 15w amp and go...it resulted that from IC12 forward music could be heard on every component until the region of c30, c31, r85 and finally IC13...Could be a fried cap maybe?
Moving forward I also did the test you suggested...removing IC13 but probing on IC11/p7 no wave...the only audible thing is just a slight whistling noise that my 9v adapter makes. When I removed IC12 changes happened...no clean sound could be heard, just a distorted noise coming in sq. waves on IC13/ p2, p12 and IC/p7...does this give us any clues?

When plugging in my guitar the fuzz is more fuzz-like than the first testing a few weeks ago that sounded more overdrivish with no fuzziness. Bass switch works, tone, blend all works except for the subharm that is not present nor does change while turning the pot.

I'd appreciate any clues. I tried to explain in detail all the testing and results...frustrated. I think something must be wrong just before IC13..should I try to remove or. at least test the caps?

thank you,  Alex

Hello.

I managed to re-flew the joins on IC13, voltages are now the same as in the first measurement, must have been a bad joint somewhere.
I probed all the way from Q7 to IC11 and probably found the cause of the issue...I have the muff on Q7, the signal is fine past R82 and C12 as well as on pins 2 (3.5v) and 3 (3.5v) of IC11.
In the other side voltages on pin 5,6,7 of IC11 are p5 8.95 / p6 8.69 / p7 8.99 ...are such voltages adequate on these pins?...because there is no audible wave as before...just empty signal...does this tell me that probably the LM311N in bad? Reflew all joints on IC11 but no change. 

Hi again.

I checked and reflew some joints on IC13 dis some probing and another round voltage measurements...
While probing  I noticed no sound on pin 2 and 12, also on q4 and q8. Also theE on Q7  and IC11/p7 appear quiet this time... no muff, no sq. wave.

voltage measurements on Q4 and Q8 same as last time but consistant change on IC13 pins since last time (the component probably got busted while handling I suppose?).

1st measurements:  p1 0.00  / p2 9.04  / p3 8.99  / p4 0.00  / p5 9.03   / p6 0.00   / p7 0.00  / p8 0.00  / p9 9.03   / p10 0.00  / p11 0.00  / p12 9.03  / p13 0.00  / p14 9.03 
2nd measurement:  p1 6.99  / p2 7.65  / p3 8.98  / p4 6.99  / p5 9.03   / p6 6.99   / p7 6.99  / p8 6.99   /p9 7.00   / p10 6.99  / p11 6.99  / p12 6.99  / p13 7.59  / p14 9.03

There is a 7v on all positions that had 0.00 before...joints seem all good now...probably a fried IC then?

Thanks a lot for your help. I will try re-flow the component later and test again. In the worst cse I ll tryto find a substitute part.

Will stay in touch. thany again,

best regards,

A

Hmmm...probed all 3 positions with the same result... very distorted hot lead like sound...cant hear difference in octave of any kind...probably 4013 duff too?
...that would be the 2nd faulty part in the kit so far

Ok, redone the experiment..I actually plays as you said loud+comp on IC1, muffed on Q7 and IC11 sq. waves of distorted signal. This means the pedal works? Or is there a step 2?   

Hello Scruffie.

Build myself a probe and tried as you suggested...unfortunately none of the sounds were as you described...Both IC1/pin7 and Q/c emit a weak sound signal, on IC11/pin7 the signal is significantly stronger but linear and not wavy at all.  ..frustration. Any other options/clues suggested by the Volt measurements I posted last time?

Thanks,

best regards,

Alex

Thanks Scruffie.
Tyt and rest. I'm also having a stressful time at work, gets worse each year . I replaced also C15 with a new component just to have all parts working...still no change in sound. I ll be in touch if you find any anomalies in the latest V measurements I sent you. No hurry, I will probably have no spare time to work on the pedal until next week. Appreciate your help. best regards, A

Hi Scruffie.

Tried the pedal after the component was replaced, but no success in solving the issue.
The blend, fuzz, tone and sensitivity pots seem to work fine although still no response from SubHarm pot (no audible octave / no chance while turning pot in any direction), also bass switch does not seem
to make any consistent change in sound, just a slight change in tone is perceptible. 
I have remeasured all the values on IC pins and Transistors if you could find any clues or suspicious values... also checked all the soldering work for any cold joints and found just one anomaly that went unnoticed till now...there is a slight iron burn mark on CAP15 do you think this might have damaged the component and have a negative effect/ couse the SubHarm issue? Should I check the voltages on the cap to see if it still works fine?

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I am completely frustrated at this point. If you could give me any clue to check would be muck appreciated. Sorry for bothering you this much with the issue, I sincerely hoped it would work by replacing the  faulty IC but the issue seems to be elsewhere.