GGG Fuzz Face Help - Light but no sound

[bellinom]

Hello all, first time poster.
I just recently completed building the GGG fuzz face silicon NPN version. I followed this schematic: http://www.generalguitargadgets.com/pdf/ggg_ff5_sc_npn.pdf and this wiring diagram: http://www.generalguitargadgets.com/pdf/ggg_ff5_lo_npn.pdf

I've double and triple checked all my wiring and solder joints, and everything seems fine. When I power on and plug in, the LED lights up when I plug into the input, and gets brighter when I switch the fuzz face on. But never any sound.

I read the debugging thread, but I'm still not sure on how to check voltages. It mentions signal ground, and I don't know where that is. If there are any measurements I should take, or if I should post pics, let me know.

Thanks in advance, Malcolm

[GibsonGM]

Read the post called "DEBUGGING: What to do when it doesn't work" and list voltages etc as it asks. Makes it easier to help you!

To measure voltages, connect - probe of multimeter to battery "-" where it enters the board...use the + (red) probe to measure voltages at the device pins with the circuit powered up.   For this fuzz, signal ground is just the regular old battery ground.  (Sometimes you get other subcircuits and using their ground would throw your readings off).

It seems like you have a wiring problem, probably at the input jack re. how it switches ground to turn the fuzz on/off - can't think of any other reason the LED would change state when you plug in.  Recheck the wiring in that area!  It's easy to mess it up ;o)

[petemoore]

  Step 1 2 and three
  Read up on it.
  See FAQ, Debugging PAge, GEO..
  Find textuals on google or wiki [C&Past unknown terms etc.], sometimes it's the 'other' page which makes the page you see understood.
  ~All the answers put in the links are far superior in terms of reader comprehension than what I'm typing, + they're nearly all there.
  Suggestions:
  Clip the Black DMM lead to ground.
  See if DMM beeps when Black lead contact [probe or clip] touches the red lead probe.
  Make sure there is no 'beeping across rails' [shorted power supply] before applying power.

[bellinom]

I'm thinking my problem is with the way my input and output jacks are wired. I can't really tell what wires go where, based on this wiring diagram: http://www.generalguitargadgets.com/pdf/ggg_ff5_lo_npn.pdf I've looked up TSR jacks, but I'm having trouble knowing exactly which is which, and where each one is.

On the linked pdf, the two black wires going to the output jack are connected to the sleeve of the output jack, correct? Which is the first metal part the plug touches when entering the jack. The other lug on the jack is for the tip, right?

The stereo input jack is where I'm having the most trouble. I know which lug the sleeve is. On the diagram, the output sleeve connects to the input sleeve, correct? Then the yellow wire from the switch goes to the tip for the lug. And the battery goes to the ring.

Do I have all that right, or am I way off?

Thanks

[bellinom]

I tried measuring the voltage, but my multimeter isn't digital, and is rather hard to read, so I'm not sure what my voltages are. I do know that the voltage on the Q1 emitter is not zero, as it says it should on the last page here: http://www.generalguitargadgets.com/pdf/ggg_ff5_instruct.pdf
I guess I need a digital multimeter.

[petemoore]

  Yupp...DMM is your best buddy once you get to know him.
  Otherwise starting with a known 9v, and finding that on the VM scale may help, DMM's are a lot easier to work with though.

[GibsonGM]

On a TRS jack, the 'barrel', or sleeve - inner part of the jack, will be connected to 1 of the taps - this one touches the inner part of the plug when inserted...the arm, or 'tip' is the signal line, and will go to another.  The last one is the 'ring', which is like a switch - it connects to the shorter 'arm'.  The grounds go to the ring, and when you plug in, voila, the contact is made between ring and sleeve, completing the ground and turning on the power by connecting the grounds.  So all grounds go to the RING except the 'master ground' to the battery. 
http://en.wikipedia.org/wiki/TRS_connector   << check here, scroll down to the jack schem. labeled "B", that is what we use.  The lower arm is the hot TIP, the upper arm is the switching "Ring", and the rectangle to ground is the barrel or "sleeve"....

Just go slowly and make sure EACH wire goes where it should on the drawing. User error is the most common form of malfunction, we all do it sometimes ;o)

Get a DMM, they are like $40 for a decent one!  #1 best investment in building. The analog type is good for watching 'trends' in a measurement, not so good for instant voltage reading.  But it WILL work, if you make sure not to ever use the OHMS scale when power is applied!!!  Set it to 15VDC or whatever is closest and follow the debugging steps...

[bellinom]

Thanks Gibson.

I'm still a bit confused, is there any way you could tell me in terms of the wiring diagram I posted?

Thanks a lot.

[The French connection]

I'm thinking my problem is with the way my input and output jacks are wired. I can't really tell what wires go where, based on this wiring diagram: http://www.generalguitargadgets.com/pdf/ggg_ff5_lo_npn.pdf I've looked up TSR jacks, but I'm having trouble knowing exactly which is which, and where each one is.

On the linked pdf, the two black wires going to the output jack are connected to the sleeve of the output jack, correct? Which is the first metal part the plug touches when entering the jack. The other lug on the jack is for the tip, right?

The stereo input jack is where I'm having the most trouble. I know which lug the sleeve is. On the diagram, the output sleeve connects to the input sleeve, correct? Then the yellow wire from the switch goes to the tip for the lug. And the battery goes to the ring.

Do I have all that right, or am I way off?

Thanks

Looks right if you've done it like that. The tip (input= yellow wire) is the longer one, follow the metal part and you'll figure easily wich lug go with it. In doubt:

http://www.beavisaudio.com/techpages/PedalPower/

Wich transistor do you use? Check your pinout...and if the pinout's fine, then follow the debugging and post your voltage here.

Hope that help!

Bonne nuit!

Dan

[petemoore]

  I like to visually follow the jack 'leaf' to the lug...then check that it does what it is supposed to under all conditions [such as plugged or unplugged..I dunno, w/mono jack..]
  You can follow the metal down the side of the jack to where it bends and forms one of the stacked circles at the base [insulative wafers between conductors].. on that type of jack...
  The plug can connect and disconnect switch which the jack and plug form sometimes, or there can be a switch in the jack that the plug activates...
There are various switch counts and/or lug counts on a jack, it helps to know the exact count and where these switches and lugs are and what they do.
  Most of that becomes obvious when a DMM, the jack in question , and a mono plug is used to 'map' the jack connection count and switch count within the jack under all conditions [plug in/plug out..anything else].

[petemoore]

  With 3pdt switches it is pretty easy to miswire the switch.
  One way is to physically turn the switches lugs and the whole switch 1/4 turn and wire it.

[bellinom]

Ok, I have a DMM, but I don't know where I should be putting the negative lead.

Also, when I'm plugged into the amp with the pedal on, the light comes on, and the amp will hum as it normally does when I'm plugged in, except there is no sound from the guitar. I checked the guitar volume knob, and it's at 10.

Also, I'm unsure of the pinout for my transistors. They are marked E, C, and B, but I'm not sure where exactly the emitter, collector and base are on the circuit board. I'm using transistor sockets, if that makes a difference.

Lastly, I think my switch is wired right, but can't be sure. It looks exactly like this, http://www.generalguitargadgets.com/pdf/ggg_ff5_lo_npn.pdf  but I realized, how do I know which direction the switch should be pointing? It has four sides, so which way should be up in the diagram and which side should be down?

Any more help is greatly appreciated, as I've had this thing a while and would really like to get it up and running.

[R.G.]

Read "Debugging Thread: What to do when it doesn't work" and follow the instructions. It is a tremendous help to people who want to help you.

[bellinom]

I've looked at it and I want to post my voltages, but I'm not sure where signal ground is. Will the pot lug where the battery - connects work?

[WLS]

I've looked at it and I want to post my voltages, but I'm not sure where signal ground is. Will the pot lug where the battery - connects work?

Ground to the board! As a rule of thumb alway's ground close to the component you're checking.

[bellinom]

That's my problem, where's the ground on the board? I don't see anything labeled as ground, and I don't know enough about electronics yet to find it on my own.

[petemoore]

  The FAQ tells all about it.
  Everything with a ground mark on the schematic gets connected.
  All the voltages are referenced to ground, it's like 0.0 on a ruler.
  The ground is carried by the sleeve of the jacks and sleeves of the cable plugs.

[WLS]

You have two entry points on the board where your power source connects. One is positive and the other is negative. The negative in most cases is the ground. This is where the rings from your jacks end up connecting to.

Do not confuse this with your boards input and output this is where the tips are connected.

On a stereo jack the short tip's connection acts as a switch to complete the contact of your powersource to the ring.

Trace from the ring to the board and that should be your boards ground.

[bellinom]

Ok, I'm still not sure about everything, but I used the Ring on the input jack, and measured the voltage on the Q1 and Q2 C, B, and E.

Q1
C: 8.59v
B: 8.51v
E: 9.07v

Q2
C: 9.1v
B: 9.07v
E: 9.07v

Btw, the battery measures 9.1v.

Here are the suggested voltages from GGG:
Q1
C: 1.4v
B: 0.6v
E: 0.0v
Q2
C: 4.5v (set by trimmer)
B: 1.4v
E: 0.8v

Hope all this helps.

[MikeH]

Hmmm... obviously your voltages are too high then.  This can happen sometimes when the circuit isn't grounded.  Generally in a pedal you have a negative (actually 0 volts, but anyway) power connection on you circuit board, a negative terminal on your dc jack, or a negative treminal on your battery (or both) and the sleeves of your jacks.  These all need to be connected together for everything to be grounded correctly.