My own project: FF+Tonebender= Face Bender!

[loylo]

Hi there!
I am new to the board, and please excuse my bad english because I am french.

I have always wanted to make a FF and as I had studied the circuitry, I have noticed that it is no too far from the Tonebender circuit (thanks to fuzzcentral):
The Fuzz Face:


The Tonebender:


So I wondered if it was possible to combine the two circuit in one box. Here is my solution with a 4DPT switch:


Here we go for the layout:



As this forum is the place to be in the DIY community, here is the different problems I have to solve:
First of all, the sound of the fuzz face is not so fat to my ears. The pedal reacts much more as a OD than a fuzz. I have put a trimpot at the emitter of Q2 which is now correctly biased, but the sound still the same. What is weird too (but perhaps is it normal?) is that I have an approximatted fuzz sound at the very end of the fuzz pot and if I go back a little bit, the gain decreases in a drastic way!

Anyway, I am almost happy of the Tonebender sound. It is very fuzzy, full of gain, full of larsen! But the problem is that I have a very big "buzzz" and I just can't get rid of it. Do you think it could be due to the trannies I used which are correct hfe but too leaky?

The last problem (but not the least) is that the pedal seems to consume a lot of battery. I always take care not to let a jack plug in the pedal when I don't play it, but the first battery I used went dead very quickly! And the new battery I put in is going the same way although the input jack is correctly wired. Could it be also due to the leaky trannies?

Thanks a lot for your help!

[MartyMart]

Hi and welcome
Interesting Idea, the 50uf is just power filtering, so can be left in use for both circuits.
Try a 1K linear pot, or even better a 1KC reverse audio pot as a fuzz control, you'll
get a better "sweep" of fuzz/gain that way.
www.smallbearelec.com   has reverse 1K's available.
As for battery drain, they shouldn't consume that much so check your wiring, perhaps
it's connected all the time, even with jack removed !!

Marty.

[loylo]

Hi Marty and thanks for your answer! 
I'll check smallbearelec for the 1K reverse pot.

For the battery drain, the problem is I'd checked my circuit several times and I havn't found anything wrong. I had also check with a multimeter and there is non current throught the circuit when no jack is plugged. Can you tell me if there is anything wrong on my layout, please?

[MartyMart]

Your 20k trim pot is mis-wired, It should be rotated 90 deg, so one edge lug conects with
the 9 v negative rail, centre and lower lug get joined with a small jumper and connect
to that transistors collector  so :  3  9v neg
                                                    2
                                          &    1  Collector
At the moment you have one lug of the trim pot going nowhere !

MM.

[Dragonfly]

yep...i built one a while back...same name and everything !!!

swapping the .1U cap between stages for a 1U or .68 will help with the fatness...i like the .68....i also used a 22u cap on the fuzz pot to get more bass response...AND...i swapped the 470 ohm resistor for a 1k ....

i built mine as a NPN germ unit...pretty good sound really !

good luck !

andy

[loylo]

Thanks Andy, I'll check the different values! 

MartyMart, in fact I didn't know how to wire this trimpot. So I'd checked it with my multimeter to see how it should be plugged to make it work as a variable resistor. So as far as I can see, I am totally wrong!!! 
I'll check it tonight.

[loylo]

MartyMart, well, in fact there is no lug connected to the 9V neg, it is connected to the 470K resistor, as it should be.
So you told me to wire like this:

          3  9v neg (470K)
           2
     &    1  Collector

But can I wire like this:
          3  Collector
           2
     &    1  9v neg (470K)
as it's easier for me to put a jumper between the wiper and the lug going nowhere.

By the way, I wonder if that correction should solve my problem of battery drain, shouldn't it?

And the big buzz still here, although I'd checked the bias of Q2 (which is actually 4,5V). Has anyone faced the same problem? Could it be due to leaky trannies?

[MartyMart]

No, here's the problem :
The 9v negative should connect "directly" to the Q1 trimmer
then comes the 470 ohm and then Q2's power connection  !
Check the schematics .... unless I'm getting your switching
wrong, you need to move the black 9v connection way over
to the left on the vero layout ... yes ??

MM.

[loylo]

OK, MartyMart, that's my fault. I didn't explain that the trimmer was to bias Q2 (for the Fuzz Face, Q3 for the tonebender as there is a new stage), somy trimmer is in place of the 8k2 resistor. On my vero layout, Q2 (or Q3) is in the tranny on the upper part.

[MartyMart]

OK, I see it now, it's because the "10k" for Q1 isn't marked .... 
I thought the trimmer was for Q1 .... DUH !!
I see the 10k down low on the right hand side ....

MM.

[loylo]

My fault again! 
I'll write the "10K" and Q1, Q2, Q3 on the vero layout.

So can I wire the trimpot like this:
           3  Collector
           2
     &    1  470K ?
Thanks