GGG Fuzz Face problem!

[SpufuZ]

Hi!

Im building a General Guitar Gadgets Fuzz Face.
Its the silicon version without the trimpot.
Im using 2N3904 transistors right now.

Link to the schematic:
http://www.generalguitargadgets.com/pdf/ggg_ff5_sc_npn.pdf

The problem is that its totally silent, except for a small hiss or a little noise.
I have measured the transistors and get the following readouts:

Q1
C: 1,1V
B: 0,4V
E: 0V

Q2
C: 6V
B: 1,1V
E: 0,5V

The power supply to the circuit feeds 8,77V

I can measure a small change in AC from the guitar PUs all the way through the circuit up to R5.
After and between R5 and C3 the signal is gone.

Optional components D3 and C6 is not used.

//david

[smallbearelec]

Hi--

Presuming that you measured correctly, Q1 is not conducting. The Base should be at least .6 V positive with respect to the Emitter for that to be happening. As to Why this is, how did you build? If this on the GGG PC board, could be poor soldering. If you hand-wired on perf, maybe a wrong/bad connection. More information, pls.

[deadastronaut]

in case you dont get this working properly...there are plenty of ff's in the gallery on strip/vero board...nice and simple too..

not my kind of thing but , very very popular with diy'ers........

[LucifersTrip]

The problem is that its totally silent, except for a small hiss or a little noise.

Do you get a clean sound when the effect is switched off?

[SpufuZ]

yes i have clean tone when its bypassed... 

Im building it a GGG pcb that ive made myself.

I will check the circuitry around Q1. As you say, it seems like its not conducting.
But ive tried several transistors with no difference. So it feels like somethin around it may be wrong.

[Gus]

Check you wiring to the switch.

Lets sum the currents.
Some ohms law(I am going to use ABOUT instead of EQUAL because I don't know what DMM and when in time each voltage measurement was done and I don't know the exact resistor values)
(8.77VDC-6.00VDC)/(8.2K+330ohm) about .32ma Collector current in Q2 leg
.5V/1kgain pot about .5ma emitter current Q2
(8.77VDC-1.1VDC)/33k about .23ma Q1 collector current
(.5VDC -.4VDC)/100k about .001ma bias current in the 100k feedback resistor

.23ma+.32ma is about .5ma so the currents appear to sum up(if the 1K gain pot is less than 1K the current would calculate higher, example .5V/.9K = .555ma)

[smallbearelec]

Im building it a GGG pcb that ive made myself.

Don't presume that the devices are bad; always look first for the problems that you create yourself. First rule when you make your own board: Check the continuity of every trace. The pattern has been vetted many times, so you presume that is correct. If you made the board by toner transfer, that's likely where a bug crept in. Let us know how it goes.

SD

[Gus]

I am surprised no one corrected my post.
One should ask how can there be .5ma in Q2(Si) emitter leg and .32ma in Q2s collector leg?  Also there is .23ma in Q1 collector leg.  There is a node Q1 C, 33K and Q2 B

I would check the connections at Q1 you might have an open from the 33K to the collector of Q1.  SB posted about checking Q1 and checking your board.

Check your solder joints.  
check Q1 for an open collector to 33K
check Q1 for an open emitter to ground
Check Q1 base connection

[SpufuZ]

I got my BC108A transistors from banzai today and with them it worked!

Very nice tone, but i have a quite high volume buzz, sounds like some grounding problem, and when i touch the enclosure or any grounding point it gets a little quiter.
Any ideas of what to check? I have resoldered all grounding points to make sure theres no bad solders.
Also when i touch Q2 the buzz increases a LOT.

[Govmnt_Lacky]

Check for ground loops. Make sure that the board is completely isolated from the enclosure. Also, som epictures wouldn't hurt either! 

[SpufuZ]

Pictures coming! 
Board is completely isolated from enclosure.
How do i check for ground loops? 

Found out some new things today.
The buzz almoast disappear when i touch the cans of Q1 and Q2 at the same time with my fingers.
The buzz increases a lot when the volume control on the guitar is all the way down.
When i turn up the volume on the guitar it decreases.

[SpufuZ]

Discussion continued here
http://www.diystompboxes.com/smfforum/index.php?topic=86676.0

[petemoore]

  Check and get a for sure ground [cable sleeve].
  Use wire or testclip and put ground where your hand makes it quieter, don't connect it to your hand.
  If that helps, find a neat way to solder it in there or use a ground tab/lug, might be one where the jack bolts in, check the sleeve/enclosure continuity.