Easy Face Debug -

[BarnabyHooge]

Easy Face...ha....

So here it is. I built this a few months ago but took a break before coming back to it. My self esteem needed to be rebuilt before I could face my disaster again.

1. The pedal "works" in bypass mode. There is no signal when the effect is engaged.
2. It's a Joe Gagan's Easy Face as found here:http://www.tonepad.com/getFile.asp?id=36. I used that schematic and did a layout on perfboard which I did by hand and on Illustrator. I can post that when I get home tonight if it's needed but I really took A LOT of time and care doing the layout, so I think it's fine.
3. No modifications except that the .o1 electrolytic cap is not electrolytic because they don't make them, everything else is as indicated on the diagram
7. Out of circuit battery voltage is up around 9. I left that voltage at home but I know it's a new battery.
    Voltage at the circuit board end of the black battery lead =  8.71


Here are the other readings.

Q1
C = 8.77
B = 8.71
E =8.8

Q2
C= 8.8
B= 8.77
E= 8.78

Based on the other debugging threads it seems WAY off. I may need to salvage what I can and try to rebuild, which wouldn't be the end of the world. Let me know if you need anything else or if maybe I should take up knitting instead.

PS> It made an audio probe but got no where with it. I guess I still don't understand how the circuits carry the signal exactly. I've read  books and anything on the internet I could find, so I understand the parts well enough, just not the sum of what the parts are doing together. If you have any suggestions for that kind of reading I should be doing I am all ears. Oh, I did read, read, and re-read the technology of the Fuzz Face article that gets refrenced around here a lot, but some of it was over my head.

Thanks,
BH

[joegagan]

your voltages indicate that you are dead shorted to 9v everywhere.

you probably have something crossed up in the wiring that is making everything hot, or you are lacking a major ground somewhere.

[BarnabyHooge]

Ok, that kinda what I thought because all of the readings I took were kind of in the same ball park.

"missing a major ground", would that be like from the board to the output jack or that a major ground connection (btw Q1 collector and the GRD) is not being made properly?

Thanks a ton for your prompt response.

[petemoore]

  If you have PNP's and you want a for sure ff, start with a PNP Pos Gnd schematic..

[BarnabyHooge]

Can anyone clarify the "lacking a major ground" comment? I double checked my wiring and it seems to be ok.

Also, can anyone reccomend a "narative" of how the signal works its way through a basic circuit? I think I understand what happens but I would like to verify my thinking.

Thanks.

[axg20202]

You've probably got a blob of solder/bridge linking your V+ to your ground somewhere on the board. I assume you are using a PCB. Check it over with a magnifying glass to make sure all traces are clean with no bridges between traces that shouldn't be there.

EDIT: i see that you are in fact using perf. You've got an error somewhere then, which is linking your 9V line to your ground. Could be anywhere on the board or off-board wiring.  Check, check, and check again.

[joegagan]

yeah, sometimes i wonder if newbies are using the continuity checker on their multimeters as much as they can ( no offense anybody)


often the fastest route to knowing where it went wrong is to see what is hooked to one another that isn't supposed to be.

removing trannies from sockets if you have sockets also reduces the variables while you do this

[petemoore]

  Measuring resistors in circuit:
If they measure what they're marked..cool.
  If they measure less than marked...probably there's an alternate path for current through the circuit and you are measureing more than 1 resistor paralleled..in which case..
1 ballpark it or figure it's about what the small resistor is marked [when the big resistor is say 4x the resistance..the small resistor will measure near what it's marked, a bit less...
2 Do the math on the paralllel resistors you're measureing [the one in circuit and the other path[s through the circuit around that resistor]
3 lift one end and measure it again...
  10% tolerance resistors, 99.999% of the time, measure within 10% of marked value [hardly ever get a bad resistor].
  Debugging page walks through all this...
  and you'll soon be flipping between diode/continuity checker, voltage ranges, and resistance measurements on the DMM...while figureing out every possible relevant way to apply the meter to the circuit.
  Understanding electron flow...using 'water analogy' helps to understand ohms law, barring that, posting voltage measurements of bias points to ground...we'll help cypher out any relevant information for you.
  Also, I'm 1/2 certain we're typing about an EZ face PNP Pos Gnd., but a schematic reference is worth 1,000 words.
 

[BarnabyHooge]

Sorry if these questions seem ridiculous. I realized my comprehension was not what I had thought so I'm asking any question I don't know 100%.

I guess I'm not using my continuity tester as much as I could...lesson learned.

Schematic is posted above.

Thanks everyone.