Help needed! Having problem w/ Fuzz Face clone (IT WORKS!!)

[brianh]

Hi guys, first post.

Recently I built a FuzzFace clone on a perf board. Worked great but I had an odd problem with noise when my guitar's volume was turned down.

So I rebuilt it with new parts: etched a board using the generalguitargadgets.com circuit pic along with their negative ground PNP layout w/LED. Populated the board with germaniums from Small Bear, metal + carbon film resistors, a mylar .01uf, radial Xicon electrolytics, Alpha pots.

I fire it up and nuthin. Well, almost nuthin. It works in bypass, but when on I only get a slight sound with the fuzz knob around 0 to half way up, and with the volume up high. Otherwise no sound. If I wack the guitar's strings, I can get a weird crackly sound from the amp. Not like crackling due to a loose connection, but like a "high tech" buzzing crackling. The light comes on and the board measures 9V. I've tried replacing all the resistors, .01uf cap, and the pots. The germaniums are socketed so they never saw any heat. I tried another set of germaniums and those didn't work either.

What could be causing this? Where do I go from here? I'm a newb and am at a loss.

I don't have any pics of the completed pedal, but here are shots of the board:





thank you in advance!

[b_rogers]

post all your trannies voltages, so we can make sure its not a bias problem

BTW you did a good job...looks nice.
like this..
q1
c
b
e

q2
c
b
e

Brent

[Fret Wire]

Post your battery voltage also.

[Ge_Whiz]

All ground connections thoroughly secure?

[BILLYL]

I checked those solder joints. Try touching them up - a little heat and remelt some of them - the grounding looks like you have alot of solder and a possible cold joint.

BILL

[petemoore]

I like my ROTM [run of the mill] trannies for testing circuit boards, nothing like an active to see if an actives wiring works, I save my precocious Ge's for use after testing...I can always get at least a reasonable Fuzz from say 3906's...even after reverse biasing and misconnecting them, when they blow [actually I've never had a FF blow a tranny] I can just 'grab another one...
 The Board looks very nice. Post all the transistor pin voltages and supply voltage...battery.

[Torchy]

I take it you are using this layout/schem
http://www.generalguitargadgets.com/diagrams/fuzzface_lo_pn_dpdt.gif

Youve got a 3k9 resistor for R5 instead of 8k2, but even worse you have a 470k resistor for R4 which should be 470ohm.

[brianh]

IT WORKS!!

THANK you everyone, especially Torchy who caught that I used a 470k instead of a 470ohm.  The 3.9k is correct... Small Bear includes different resistor values that sound good with his transistors.

I guess my initial perf build was good, too, as I'm getting the same "problem."  When I turn down my GUITAR's volume or tone knobs all the way to zero, I get more hiss.  I guess that's inherant in this pedal, correct?

Thank you!

[smashinator]

I guess my initial perf build was good, too, as I'm getting the same "problem."  When I turn down my GUITAR's volume or tone knobs all the way to zero, I get more hiss.  I guess that's inherant in this pedal, correct?

Thank you!

When I first built mine, turning the tone on my guitar to zero caused a howling noise that was kind of cool, but not desirable.  Putting a 10k (I think...) resistor in series with the input took care of ALL noise.  It's quieter than my Boss pedals now, even with everything maxed.

[brianh]

Well, here it is completed.  That hiss with the guitar's vol + tone on zero is weird, but as long as I don't put either knob ALL the way down, it's fine.  Does it with any guitar I have.  Strange!

Thanks for your help guys.  Great forum.

[Somicide]

Thats a mighty fine lookin' build.  I dig the neatness you have going on.  Heh, My first FF was done on cardboard; I poked the leads through and soldered them together that way.  Fun fun.  Someday, I may post my homemade enclosure (made from spare sheet steel), but then again, I may get laughed out of here for it...

Peace n Love,

Jeff

[brianh]

Thanks!  I'm real obsessive about the neatness, at least as best as I can do.

My first attempt at this on perf board was much messier!

I need to get new screws for the NSC enclosure.  The screws included are AWFUL!  The heads are way too big for the holes and stick out pretty badly.

[Kleber AG]

Really nice finish/letters!!!  

But now it's possible to understand the noise(oscilation) you had been talking about, it's because of that two wire "blue and violet" from your in/out jacks, they can't be that close. Neither those two wires (blue and violet - in/out_jacks), neither the in out jacks...

IMO: You better have the two jacks (in/out) one at each side of the 3PDT switch, at the oposite side box walls. To reduce the risk of in/out oscilations.

When you turn you guitar volume down your circuit starts to pick whatever it finds and oscilates...

Try routing that violet wire at the jack to the oposite side, above the fuzz pot until the DC jack, then go down to the switch.
Keep wires that are related to the in side of the circuit away from the wires related to the out side of the circuit.

You 3PDT bypass arrangement looks weird!? :?  Are you grounding the output of the fuzz when in bypass mode instead of the input of the fuzz???

Hope it can help somewhat, I already had lots of oscilations to fight with pedals :x
Regards
Kleber AG

[petemoore]

I take it you are using this layout/schem
http://www.generalguitargadgets.com/diagrams/fuzzface_lo_pn_dpdt.gif

Youve got a 3k9 resistor for R5 instead of 8k2, but even worse you have a 470k resistor for R4 which should be 470ohm.

That R value was misvalued many times on my FF's...I just had a mental 'skip' and grabbed a Yellow Purple Yellow for some reason, and it would take me alot of time to find where It'd gone awry.
 Picture is worth a thousand words.

[phillip]

Nice build!  Where'd you get that nice lookin low-profile LED bezel?

Phillip

[Kleber AG]

well by "violet" I mean "purple" sorry :?
Kleber AG

[Hal]

propz, thats a SWEET build

remember to be careful when using adapters on your FF - since its posative ground, you can't daisy chain it.  Results could be bad!

glad you got it working :-D

[brianh]

Really nice finish/letters!!!  

But now it's possible to understand the noise(oscilation) you had been talking about, it's because of that two wire "blue and violet" from your in/out jacks, they can't be that close. Neither those two wires (blue and violet - in/out_jacks), neither the in out jacks...

IMO: You better have the two jacks (in/out) one at each side of the 3PDT switch, at the oposite side box walls. To reduce the risk of in/out oscilations.

When you turn you guitar volume down your circuit starts to pick whatever it finds and oscilates...

Try routing that violet wire at the jack to the oposite side, above the fuzz pot until the DC jack, then go down to the switch.
Keep wires that are related to the in side of the circuit away from the wires related to the out side of the circuit.

You 3PDT bypass arrangement looks weird!? :?  Are you grounding the output of the fuzz when in bypass mode instead of the input of the fuzz???

Hope it can help somewhat, I already had lots of oscilations to fight with pedals :x
Regards
Kleber AG

thanks for the tips!  I'll try your suggestions.

As far as the 3PDT layout, I followed this: http://generalguitargadgets.com/diagrams/fuzzface_lo_pn_3pdt.gif

[Curt]

About the hiss...be sure that Q2 has the higher gain (Hfe).  Also, you really should post your transistor emitter, base and collector voltages here.  If they are off, you might want to alter Q2's bias resistor.  That can make a WORLD of difference in the sound.  Lastly...when built as a neg. ground circuit, a Fuzz Face WILL do strange things with the guitar volume turned down.  This thing was never designed as a negative ground circuit.  First one I built was neg ground, sounded like a howling wolf when I turned the volume down.  I ended up rewiring it as a positive ground.  JD doesn't have a layout for the LED with positive ground, but it's easy to do.   I never use an external power supply with mine, batteries last a LONG time and sound better.  Now it's just about my favorite distortion peddal...I have a list of folks wanting me to build one for them.

[brianh]

propz, thats a SWEET build

remember to be careful when using adapters on your FF - since its posative ground, you can't daisy chain it.  Results could be bad!

glad you got it working :-D

thanks!  Actually I followed a PNP negative ground diagram, so I could use it with my Voodoo Lab pedal power.