Boutique Fuzz Face troubleshoot

[dosmun]

I am building the 69 Boutique FF from General Guitar Gadgets.  I got the Transistors from Small Bear.  I am building the PNP negative ground version and using a Board from GGG.

http://www.generalguitargadgets.com/v2/diagrams/fuzzface_b_sc_pn.gif

http://www.generalguitargadgets.com/v2/diagrams/fuzzface_b_lo_pn.gif

The controls seem to function somewhat but I am getting no Fuzz.  The voltage measurements on Q1 are all near 9v and Q2 are around 7-8volts on all pins.

Any suggestions on what might be my problem.

Thanks in advance

[brett]

Hi.
You've definately got some funny voltages happening.  The collector of Q1 should be around 1V under the battery voltage.  Adjusting the trim bias should let you get 4 to 5 V on the collector of Q2.

First, check that the transistors are the right way around, and second, that the base of each transistor is about 0.3V lower than the emitter.  If the base isn't in this range, check that it isn't earthed somehow.  These measurements are just a start.

cheers
Brett

[dosmun]

I will give that a try tonight.

[dosmun]

I remeasured all of my voltages and here is what I have:
The #'s in () are what GGG says they should be close to.

Q1
E  8.9  (.5)
B  8.8  (.1)
C  7.5  (0)

Q2
E  7.6  (.4)
B  7.5  (.5)
C  4.9  (4.5)

[dosmun]

Bump

[petemoore]

IIRC Phillip showed a schematic that may have helped helped make the PNP Neg Gnd FF work. I didn't notice whether that worked or not.
 Alot of Ppl have had troubles with that one, up till just recently the fix was use a PNP Pos ground schematic...Maybe it still is, if you go back about a week or so, there's a schematic in a post [pretty certain it was Phillip] from which you can graft elements that [may?...will?] cause a Pos Gnd PNP FF to work.
 I would suggest to those about to endeavor on this to start with 3906's [or leaky Ge's you don't care about much] so as to avoid reverse PSing any prized Ge transistors, at least until it's working and stable.

[Fret Wire]

Pete, I remember the post but can't find it. Was it GGG's Boutique or standard fuzz pcb that didn't work? Pos ground or neg, or both?

[dosmun]

The GGG Boutique FF is what I have.

[dosmun]

I did a little searching and found that others had similar problems.  Does GGG test their stuff before they post it on their site?  It sounds like the PNP neg ground does not work.

[Fret Wire]

Did you find the thread? I couldn't remember which version, and which grounding schem. had the problem. I wanted to make sure before I said anything. Since the FF has a low battery consumption, it may be better to forget power supplies and just go with the positive ground version. I believe a few had that problem with that particular layout, but never posted their final build results.

[petemoore]

But I go along with: FF's do better with batteries, the internal resistance of the battery is part of the FF circuit PS's have none there.
 PS ripple is very evident in the signal path of the Feedback Loop circuit, I remember the schematic had the Q's 'upside Down' [collectors on the bottom], asked what;s up with that [I couldn't see how it could work in any conventional way or otherwise],
 Yes there have been many converts to convention [going from PNP Neg Ground circuits that didn't work 'till being converted to PNP Pos Ground] for those with Selected Ge's for FF use.
 If you know something I don't, please tell me.
 If I were to build a PNP Ge FF, it would be a Pos Ground version. and I would test it with non selected transistors until I got it working consistantly.

[dosmun]

I am switching to the Pos ground version.  Hopefully that will solve my problems.

Thanks for the Tips.

[Chris R]

I remeasured all of my voltages and here is what I have:
The #'s in () are what GGG says they should be close to.

Q1
E  8.9  (.5)
B  8.8  (.1)
C  7.5  (0)

Q2
E  7.6  (.4)
B  7.5  (.5)
C  4.9  (4.5)

you got the voltages mentioned from ggg turned around.

E   0
B  .1
C  .5

However these voltages are for a positive ground ckt..  the voltages you have seam about right.. ie 9 voltes for the Emitter of Q1..  and the collector is about 1 volt under Q1.  Q2 voltages look ok too..

If your still not getting any fuzz.. i would check the wiring of the pots.

C

[petemoore]

To change is easy.
 Reverse the battery connections. Reverse the 22uf cap.
 If you're using film caps for input and output, they need to be left alone unless you want to change their values.
 If they're polarized caps reverse the polarity of them [or change them to nonpolarized ones.]
 Oh make sure the emitter is at the 'bottom'...Q1 emitter should be at ground.

[dosmun]

Ok I changed to the + ground version.

Again everything seems to function except the Fuzz  is VERY weak unless it is maxed out.  This is pretty much the way it worked before.

The circuit will not work unless the 10K trimmer is set to 0 ohms.

Here my latest measurements:

Q1

E  0
B  75mV
C  1.3

Q2

E  1.2
B  1.3
C  3.3

So far this is going nowhere fast :roll:

[brett]

Hi again.  As I understand it, you've switched to the pos earth PNP circuit.  Cool   .  Everyone gets that one going eventually.

Here my latest measurements:

Q1

E 0
B 75mV
C 1.3

Q2

E 1.2
B 1.3
C 3.3

Something is decidedly odd here.  If you are working POSITIVE (9V) to earth, the emitter of Q1 has to be at 9V.  Maybe you're reporting the voltages relative to earth and they are negatives?  In any case I'm suspicious that your transistors are in backwards.  THat would account for your very low gain.  (Backwards, you get a hFE of about 5 to 10 instead of 50 to 150.)

Looking from the *TOP*, most PNP germaniums have the following pinout;

collector
..............base
emitter

ie like a ">" sign with the base on the right and the emitter on the bottom.

Apologies if you've already triple-checked this.

Don't give up because there have been 100 troubled fuzz-face builders before you and 99 of them got it going.

cheers

[petemoore]

Tha'ts the way I decided to think of it..[because all the Ge's arent the same pinout] [all my Ge's are the same in this manner and I suspect most are] the pins form an arrow that points toward the out put...the middle offset pin being the tip of the arrow.
 Plus most have that tab on the cap over/by the emitter.

[petemoore]

I make a three hole perf extension for the Hfe tester on my DMM that has the long enough leads soldered out of the bottom for the sockets pins. That way I can EZ check transistors and check transistors with trimmed leads.
 Just stick the transistors in the PNP side and you should be able to determine the proper pinout from the Hfe readings on the DMM. I usually stick them in different ways, the one with the highest Hfe will show the pinout.

[dosmun]

The Sheet I got from small Bear shows the pin layout as:

E
 > B
C

This is a bottom view.  I didn't catch that yours was a TOP view at first.

[dosmun]

Success Guys.

I feel like a Dumbass now.  The tranny's were switched.

I actually had everything right the first time I tried it but it didn't work and I switched the tranny's around.  I think I also fixed a loose wire too on the first time around which was the actual problem to start with.

I believe the Neg ground version might have worked.  I may try it just to see.

Or maybe not. :lol:


Thanks again for your help you  guys Rock.

I have a Big Cheddar and  Rat clone boards already soldered up I just need to get them in boxes and see if they work.