Fuzz face only working with LPB2 boost on

[Chris S]

What I have done: Have built a negative ground fuzz face and a LPB2 from generalguitargadgets schamtics (with small bear parts for fuzz) in a box with an EA trem and some mic preamps that are positive ground and so I am using Max 1044 to invert the current.

I have build all of these pedals in seperate boxes before an they work fine

Problem: The fuzz is only working with the boost on. I am running the boost so it is at the same level as when in by pass so it isn't actually boosting but just going through the curcuit.

Attemps to fix: Have double checked everything and compared to previous schematic and build, and all seems to be the same.

Any suggestions greatly appreciated.

[petemoore]

This is the best [easiest] way for us to explain it...
   Sticky: What to do when it doesn't work

[Chris S]

Sorry...

Description: With out the booster on there is only very ocassional sound (like it has a gate on it) and that sounds like a horrible breaking up kind of sound

part substitution or mods
R2:39k
R3:150k
R4:470
R5:3.9k
R6:1k

Curcuit voltage 9.30
out of cucuit:9.30

Q1
b:9.19
c:8.58
e:9.30

Q2
b:8.58
c:3.04
e:8.70

Anything I have left out?

[petemoore]

Sorry...

Description: With out the booster on there is only very ocassional sound (like it has a gate on it) and that sounds like a horrible breaking up kind of sound

part substitution or mods
R2:39k
R3:150k
R4:470
R5:3.9k
R6:1k
 >>>NPN Transistors...[?]

Curcuit voltage 9.30
out of cucuit:9.30 {+ ?}...if you're using a PS you hafta watch polarity.

Q1
b:9.19
c:8.58
e:9.30
 Somethings wrong with the bias, pinout or something here, Collector toward V+ base in the middle, and Emitter nearest ground, looking at schem.
Q2
b:8.58
c:3.04
e:8.70
 Same here, Base above emitter by at least .6v, collector should be near 1/2v or 4.65v...[you have collectors written in the middle on this posting...generally speaking it goes:
 C
 B
 E

Anything I have left out?

Did you use sockets for the transistors?

[Chris S]

Transistor sockets? - no I didn't
V = 9.30+

I've double checked the readings and they are still  
Q1
c:8.58
b:9.19
e:9.30
Q2
c:3.04
b:8.58
e:8.70

My initial thoughts were that I could have fried something or put the transistors in backwards or in each others places - I guess what had me baffled was that it works with either the LPB2 booster on before it or the EA tremelo on before it. (just tried that last combination in between posts) And I cannot work out why that would be.

THANKS!!!

[petemoore]

Have you tried adjusting the value of Q2's collector resistor on the FF?
 Those voltages all look high, the emitters should be a low voltage reading...I think there may be a miswire, I've never tried a MAX1044, so can't advise what that entails.

[Chris S]

Hey Peter, I tried using a friends power pack and everything seems to be working fine. Grr! (sorry to waste your time with this)  I knew my power pack was reading high but I there is obviosuly more to it than that. I had tried an unregulated 9V power pack which stopped the EA Tremolo from working as well. My multi meter doesn't read Amps could that have been the problem?

Thanks Heaps fro your help though! I might just switch power packs. I'll try to post some picks of the pedal too - it's a big 3 in one thing.

[Chris S]

Hey Peter, I tried using a friends power pack and everything seems to be working fine. Grr! (sorry to waste your time with this)  I knew my power pack was reading high but I there is obviosuly more to it than that. I had tried an unregulated 9V power pack which stopped the EA Tremolo from working as well. My multi meter doesn't read Amps could that have been the problem? Time to buy a new power pack I think.

Thanks Heaps fro your help though! I might just switch power packs. I'll try to post some picks of the pedal too - it's a big 3 in one thing.

[MartyMart]

Hey Peter, I tried using a friends power pack and everything seems to be working fine. Grr! (sorry to waste your time with this)  I knew my power pack was reading high but I there is obviosuly more to it than that. I had tried an unregulated 9V power pack which stopped the EA Tremolo from working as well. My multi meter doesn't read Amps could that have been the problem?

Thanks Heaps fro your help though! I might just switch power packs. I'll try to post some picks of the pedal too - it's a big 3 in one thing.

There's some information about this at "Fuzz Central" and people here have said that the "Fuzz Face" needs to be "battery powered" only !!
IE: Roger Mayer's FF's are only ever battery powered !!  
Your close, so give that a whirl...

Marty.

[AL]

It sounds like your circuit may need some biasing. I'll second petemoore's suggestion - adjust Q2. The easiest way would be to wire a pot in there and adjust until you get a sound - 10K, 20K or a 50K should work just fine. Once/if you get the sound you're looking for measure the pot and put in the appropriate resistor.

AL

[Chris S]

Thanks tried that.

The good news is when I replaced the Q2 collector resistor with a 10k pot
1) I fine tuned the sound for when another pedal is on
2) I've discovered that when my tuner is plugged in but not switched (in fact not even in the chain) the problem goes away also

The bad news is
1) The problem is still their

The solution I think for me will be use batteries or plug in my tuner.

Thanks for all your help

[AL]

Oh !!! Wait a minute. Take everything else out of the chain (physically remove then not just bypassed) and see what happens. Fuzz Faces are mean little guys and they don't like other pedals. They seem to work best when it's just guitar - FF - amp. They will work occasionally with other pedals but that seems to be hit and miss. Try it by itself and see what happens.

AL

[Chris S]

Physically removing the other pedals maybe a little hard...

http://www.geocities.com/chris_summerfield/inside.jpg

They all share a common 9v and earth

[AL]

Ouch !!!  :shock: OK then... First off, that's a really cool idea and I wish I had half of the patience you do. I can't even imagine attempting that.

But, it looks like all of them have their own seperate input and output jacks. Can you just remove the wires and run the FF by itself? It may be a pain but it's probably best to divide and conquer and not try to solve everything at once. You don't need to actually physically remove it - just unsolder some wires so the FF is all by itself and take it from there. Also, FF's are suspect to interference - all those wires could be picking up quite a bit of unwanted noise. I would also try cleaning the wiring up a bit.

AL