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DIY Stompboxes => Building your own stompbox => Topic started by: cdc3j on June 01, 2011, 03:52:07 AM

Title: GGG 60's Fuzz Problem
Post by: cdc3j on June 01, 2011, 03:52:07 AM
Grrr.... I know this thing is wired correct (according to this anyways: http://www.generalguitargadgets.com/pdf/ggg_ff5_lo_b69.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a (http://www.generalguitargadgets.com/pdf/ggg_ff5_lo_b69.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a) ).

I had the 2N2369's installed first and couldn't get any sound through the pedal when engaged. I could get some crackle from the contour knob when every other knob was maxed, but that's it.

I switched to the 2N3906's and have a little sound when everything is maxed but I know it's not right.

I get bypass sound no problem and the LED is bright. I have tried it with a battery and a one-spot.

Is the layout wrong? I did some searching and found several threads of people experiencing problems but didn't find much help.

I have added the R1, C4, C6 and D3 componets.

I would love some help if anyone can contribute....
Title: Re: GGG 60's Fuzz Problem
Post by: petemoore on June 01, 2011, 07:19:44 AM
  Looks like it's a fanci-fied Fuzzface.
   PNP/Positive Gnd. FF, all polarized components must have their _ and + orientations follow the power polarity.
  If a reverse polarization took place, the reverse polarized capacitors would be ready for ''damaged ?/..Yes = toss 'em!'' status.
   Measure the 2 transistor amplifier active component lead nodes voltages from ground.
   
Title: Re: GGG 60's Fuzz Problem
Post by: LucifersTrip on June 01, 2011, 07:33:29 AM
Note that you switched from an NPN (2369) to a PNP (3906) transistor, so all the +/- caps and the +/- battery must be reversed.

So, unless you did that, the 2369 had no chance of working with the PNP layout you linked to.

...and you have a better chance of getting help if:

(http://www.luciferstrip.com/fuzz/debug.jpg) (http://www.diystompboxes.com/smfforum/index.php?topic=29816.0)
Title: Re: GGG 60's Fuzz Problem
Post by: cdc3j on June 03, 2011, 12:39:53 AM
Ok so I have a couple questions about debugging. Since the LED will come on, should I check with the effect "on" or off? What should I check besides the c,e,b of the transistors?

Confession: When I first finished the effect I plugged in a one-spot. I had the PNP geranium transistor installed because that's what the layout called for. The LED came on but I had no sound through the fuzz. I switched to a battery for all the tests since. Could the one-spot have fried the transistors? I later switched to the silicon (not understanding the NPN PNP thing yet, and with them possibly reversed) and got a very low, fuzz-less sound when all the knobs were maxed. I have since switched back to the germanium transistors.

I have checked and rechecked the wiring and solder joints. I'm sure it is wired exactly as this layout dictates

(http://i836.photobucket.com/albums/zz289/cdc3jj/60sPNPfuzz.jpg) 

I believe the electrolytics are reversed on the layout because this one which shows a NPN silicon based fuzz has them reversed

(http://i836.photobucket.com/albums/zz289/cdc3jj/70sNPNFuzz.jpg)

I did notice some differences in the power and input jack-to-battery wiring when looking at the PNP simple fuzz face layout seen here

(http://i836.photobucket.com/albums/zz289/cdc3jj/PNPfuzzface.jpg)


I'm seriously hopeful I haven't fired anything. I have a multimeter and I'm willing to check every solder joint if I need to. Thanks for your help so far. I added some pics incase there's something I'm overlooking.

(http://i836.photobucket.com/albums/zz289/cdc3jj/photo2.jpg)
(http://i836.photobucket.com/albums/zz289/cdc3jj/photo4.jpg)
(http://i836.photobucket.com/albums/zz289/cdc3jj/photo3.jpg)