Help with Supa Fuzz build (please!)

[peps1]

Having a bit of a nightmare with this Supa Fuzz build, so thought Id would ask you guys for a little help!

as 9x out of 10 its transistor issues, here is the info.......Im using 3 Philips OC75, and have wired them up though the breadboard with matching color to the diagram below (RED= E Yellow=B Green=C)  and am going by the Collector being indicated by the red dot on the transistor.

Anyone spot anything glaringly obvious, or have suggestions?   

[Quackzed]

so the red dot goes to the green wire... you didn't accidentally do red dot to red wire?   
other than that, you could look up the pin out for oc 75 or use a pot for the collector resistors and adjust bias for each tranny
measure collector and adjust bias for  4.5v then if all else fails, build an audio probe...

[peps1]

so the red dot goes to the green wire... you didn't accidentally do red dot to red wire?   
other than that, you could look up the pin out for oc 75 or use a pot for the collector resistors and adjust bias for each tranny
measure collector and adjust bias for  4.5v then if all else fails, build an audio probe...

red dot defiantly goes to the green wire...

not got a spare cable to build a audio probe at the moment

[Barcode80]

you don't need a cable to build the probe.

solder one end of a 1uF cap to the tip connection of a 1/4" jack, solder a wire to the other cap lead. this is your hot signal wire. Then solder a wire to the sleeve to use as a ground wire. plug in your output cable to the jack, boom audio probe.

[peps1]

just found my audio probe......will probe and post!

[Quackzed]

other than that, i can see that your jacks are grounded and that a black wire goes to the pcb -cant tell, but it looks like its on the opposite side of the board, it is making good contact? also is the input jacks prong connectors making good contact with the tip and ring terminals of the cable?
if everything is wired ok, then its probably the transistors or how they are biased...
or the battery is dead?
switch gives bypassed signal yes? that is, the guitar is heard normally in one switch position, then muted in the other?
if you have a dmm, multi-meter you can measure the collector voltages and see if they are aroung 4.5v (i'd guess that it would pass sound if so)
you sure your breadboard connections are ok? making good contact?

[peps1]

Audio probe results

Green = Audio
Blue= Really really faint
Red= No audio

[peps1]

After a good night sleep, and getting out the house THINK I may have worked out the problem.............the circuit should be positive ground, right?

[peps1]

Switch polarity and it worked for about 5 minuets, though the attack pot did nothing, and now its all stoped working     

here are the new probe results

Green = Audio
Blue= Really really faint
Red= No audio

[Scruffie]

Feeding the Pots 9V by mistake when you had the battery the wrong way round blew them? And obviously that output cap is a bit suspect if the audio is dying there.

[peps1]

Feeding the Pots 9V by mistake when you had the battery the wrong way round blew them? And obviously that output cap is a bit suspect if the audio is dying there.

Can that happen? never blown a pot before.

[Scruffie]

Feeding the Pots 9V by mistake when you had the battery the wrong way round blew them? And obviously that output cap is a bit suspect if the audio is dying there.

Can that happen? never blown a pot before.

Yeah, Pots aren't all that wonderful in design so I beleive it can if subjected to zero resistance and a high enough voltage.

[Barcode80]

Feeding the Pots 9V by mistake when you had the battery the wrong way round blew them? And obviously that output cap is a bit suspect if the audio is dying there.

Can that happen? never blown a pot before.

Yeah, Pots aren't all that wonderful in design so I beleive it can if subjected to zero resistance and a high enough voltage.

not at 9v though. at least not at the small current of this circuit. I'd point to the output cap.

[Scruffie]

Feeding the Pots 9V by mistake when you had the battery the wrong way round blew them? And obviously that output cap is a bit suspect if the audio is dying there.

Can that happen? never blown a pot before.

Yeah, Pots aren't all that wonderful in design so I beleive it can if subjected to zero resistance and a high enough voltage.

not at 9v though. at least not at the small current of this circuit. I'd point to the output cap.

Well that's what I thought, till I saw this thread, the pedal in question is only a 9V pedal - http://www.diystompboxes.com/smfforum/index.php?topic=87566.0

But yeah, the Output cap has been suspect before and after the polarity change.

[peps1]

Well I switched out the 1K pot, the 10nf, 0.01uf and 47nf caps......still exactly the same problem and probe results as before 

 

[Quackzed]

did you correct the polarity of the electro caps ? - to ground (old positive)
check for anything that might be shorting out that .01 or 50uf cap to ground.. flux ...solder bridge?
if you have signal around the 8.2k you should get the same signal at the bottom of the .01 uf cap, and a slightly less bassy version on the other side, if not the signal is leaking to ground somewhere...

[peps1]

  WORKIG!

A big thank-you to everyone that helped.

Ok here was a epic list of problems, Duff breadboard, cold solder on the switch & the PCB.

Iv got to say Im a little shocked at how aggressive the peddle is, its real untamed raw fuzz! are there any easy bias mods?

[Scruffie]

WORKIG!

A big thank-you to everyone that helped.

Ok here was a epic list of problems, Duff breadboard, cold solder on the switch & the PCB.

Iv got to say Im a little shocked at how aggressive the peddle is, its real untamed raw fuzz! are there any easy bias mods?

It's simmilar to the Tone Bender MkII isn't it? That'd be the Q2 & 3 Collector resistors then.

[peps1]

Same as the Tone Bender, but with a limiting resister I think.

(ps check your inbox  )

[Quackzed]

ah ha! another troop of electric gremlins brought down by determination and the desire for fuzz
bravo! see, there IS a light at the end of the dark tunnel after all.
glad you got it going.
onward and upward!
and like a true diyer, you went from 'it works!' - to - 'are there any mods?' in one post!  
hell yeah!