fuzz face volume ?

[clamup1]

i hooked the trimpot up to the c and the b of Q2. it fattens it up some. with the trim pot half way i can turn the guitar down some but still have to have the amp up. it still fuzzes. it may be the trannies?

[clamup1]

i etched this myself from this:

i flipped the pic and added the values.

is this the right board or do i have to use the one zombie wolf recomended

[clamup1]

sorry lots of ?'s

does this pedal being neg ground have to be hooked up to a switch differently than pos ground. i have it hooked up like this
3pdt
board input  x x x board output
        input   x x x  output
jumper to 9 x x x jumper to 3

i dont have an led hooked up to this.

[clamup1]

this is what i have so far. hopefully someone can spot a prob

[deadastronaut]

hi chris...

heres a 3dpt wiring diagram...with led...(google is your friend)

http://img.photobucket.com/albums/v75/kev93_10/3pdt-wiring_png.png

as for your trim pot..i think it should be replacing the 8.2k resistor to bias it ....not going across the c ,e ,of the trannie!!!!!!....

check back to pete's advice...he tells you there....

thats exactly what i had to do.

good luck.

[petemoore]

  Ohms laws all complicated 'n stuff.
  So...apply the DMM anyway, and anyway you can apply the DMM.
  Distant point measurement may include resistor, solder joint, wire, solder joint, battery clip...all in one resistance measurement [say from Q2C through battery...should read what is Q2CR + 330ohm [or was it 470?], whatever the trimpot at 8k2 position plus the smallest resistor in the FF. If you read something reasonable readout...you should be able to watch the resistance go from 0.0ohms through about 20k on the DMM [with 20k pot in place of 8k2] as you turn the pot. That would check the pot and 3 or 4 solderjoints as well as the battery clip in 1 shot.
  Test for continuity where the schematic shows.
  Test for non continuity where it doesn't, especially where work was done near to/adjacent other conductive surfaces...easy to get an 'extra' trace.
  Measure all resistors.
  Make sure caps are in place and the 22uf or other polarized cap is polarized correctly.
  The debugging page is the debugging page, not to be overlooked by anyone who wants something debugged.

[clamup1]

thanks pet for reminding me of the debug page. (the walk of shame) lol. i found some places where i burned the traces off the board. i still have a low signal. just keep looking looking looking

[zombiwoof]

cool thanks for the replies. ok now how do you hook the trim pot to Q2?

I'm not sure if you've noticed the comment, but the trimmer replaces the 8.2k bias resistor.  Also, I'm not sure why you seem to have gone with negative ground on this, there have been many reports of problems using neg ground on a FF circuit.  Some have been able to do it, but I wouldn't try it if you don't have a lot of experience with this stuff.   You should have started with the correct circuit diagram for your germanium trannies, which would have been the germanium FF circuit, not the one you posted which is for silicon trannies.  This is getting pretty confusing, because you are using the wrong layout to begin with, and then trying to make it negative ground on top of that.  My opinion is you should go with the original scheme that is shown on the Fuzz Central page in the link (not the later silicon version), do it positive ground like the original and put the mods in that you want.  Just my opinion.

Al

[petemoore]

  Debugging makes it easier to read through the thread.
  Fresh start might make it easier.
  Start with the transistors, PNP, or npn.
  Since you have PNP, test them for gains or just build the pos ground version and see what happens.
  Since npn are easier to get useful FF out of, consider a Neg Gnd. NPN fuzzface.
  Once the ground is lifted [ie pNP Neg gnd]...knowing what a FF sounds like is recommended before messing with attempting to figure this one out, by me.
  basically everything in the debugging thread helps to make it work:
  Correct schematic is always a best start.
  Any deviance from diagram should be noted.
  Measure every resistance is good move [small handful].
  Noting polarity of everything polarized, transistors caps and diode in FF case.
  I always check for shorting power supply before applying power.
  The voltage measurements tell the story, Q2Collector resistor will bring the amplifier circuit into bias when everything else is right. As it is adjusted the voltage on Q2C will move up/down, near 1/2v of supply [about 4.5v] the power output will increase and the tone will come into 'focus.   

[clamup1]

no you guys are right. im gonna scrap this one and start over. this makes #7. oh well weekend project. thanks for your help

[Scruffie]

no you guys are right. im gonna scrap this one and start over. this makes #7. oh well weekend project. thanks for your help

My advice would be, don't jump in, or your first build will fail, honestly, read as much as you can and re-read before your first go, it can't be done by chance.

[clamup1]

i dont know why i couldnt find that the first time. the search button found some old posts on neg ground. the polar caps have to be flipped around and i may of put the + on the wrong rung of the in jack. but if the pc board i etched is wrong then it wont matter

[petemoore]

  Perfboard chunk 2x as big as small fuzzface layout probably still fits in the box.
  Schematic and filled/double checked part list.
  Start at node 1, count the # of connections there, note every mark like polarity, value.
  Repeat for node 2. Study each node with the DMM resistance and continuity settings.
  Resistors can be measured.
  Caps just work when rated, replaced after reverse polarization .
  Wires can have coldsolder and look connected.
  Gain Stage Transistors use DC potential to create an output 'wave analog' of the input [voltage increase, the output ~follows the waveshape input].
  It's like an automatic water-switch, the AC wave~ input controls the separate but larger output voltage which follows the same shape~.
  The base controls the current flow from emitter to collector. Base needs to be sitting at a certain potential [1 emitter diode drop above collector [ie near-ish the ground voltage] before electrons begin to flow. The collector needs to be 'in the middle' so it can swing the output voltage [an analog of the input waveform, enlarged] up and down from it's bias point, up toward power supply, down towards ground.
  That means emitter is lowest potential of the transistor, base is at least 1 base/emitter diode drop voltage above emitter before anything happens, collector needs to sit where there's voltage swing room up and down: about 1/2v = 4.5v [if using a 9v battery.
  Debugging page explains all this, include battery supply voltage so the other voltages have a reference point to equate to.
  Sometimes as simple as that gets caught when debugging step 1 is applied, dead battery.
  Might as well choose one of those boards and debug it, with the chops earn from the experience, for sure the other FF board problems will continue to drop like dominoes.
 
 

[clamup1]

when i hooked up the meter to the pedal,  i wasnt getting any mv at any point on the board. when i hooked my guitar up to it and played i would get a reading. i forgot to check the ground. the way i hooked up my pedal was the pic that scruffie put up. with this do i need to reverse the caps?

the only thing i think i know about + ground and -ground is that the pos is hooked to the ground of the board and the other isnt.

[clamup1]

in negative ground do all the off boarding wiring hook up the same as + ground. except for the + bat wire going to the sleeve?

[petemoore]

in negative ground do all the off boarding wiring hook up the same as + ground.
  Doesn't sound right, negative = - = Ground = +  is how i read it, this would be direct short when - and + get connected.
  except for the + bat wire going to the sleeve?
  I don't mind being lost without a schematic.
  Neg Ground:
  the black of battery goes connect to every thing with the 'tippy triangle' ground symbol, does the schematic...
  Starting with what is needed to have or get help, in the first post of a new thread recommended.