Fuzz Factory Debugging - my first build... not 100% OK

nokaster · Post by **nokaster** » 21 Oct 2007, 15:39

ok, today i finished all the wiring and soldering on my fuzz factory.

bypass = OK
LED = OK

circuit... not 100% OK

the "fuzz face" settings give me the best results, but where-ever the pots are, the effect doesn't get through on the highest strings, there is more popping than sound when i play single notes and it always sounds like i have broken speakers, every sounds gets cut of very fast.
and about all the pots have a crackle... which, to my knowledge is NOT OK with a fuzz factory...

can anyone help me with the stuff i described here?
where did i go wrong?
hopefully an easy fix...

Post by **modman** » 21 Oct 2007, 20:21

What transistors did you use? Did you measure them?
Check whether the pins are in the correct holes by looking up the transistor datasheet. Also check all capacitor values.

Your getting sound through, so you are not far off.

nokaster · Post by **nokaster** » 21 Oct 2007, 21:03

i used 2 AC122's
1st is 70hfe
2nd is 110 hfe

and 1 2n3904

i did change the caps on the input and the output to a higher value, because this is a common mod with the fuzz factory to make it less fizzy.

someone at DIYstomboxes though that maybe i should work on the bias of the transistors... but i have no idea how.

bajaman · Post by **bajaman** » 21 Oct 2007, 22:01

If you can post some pictures of your build it may be easier for us to help you fix the problem. Failing that, check and double check all connections, transistor polarity and orientation etc. What dc voltages do you have on the collectors of the trannies??
cheers
bajaman

Post by **modman** » 21 Oct 2007, 22:17

Take your multimeter and measure the voltages on every transistor pin when the circuit powered up. Hold the black lead to ground (on battery, power supply or somewhere in the circuit) and the red lead to the point you want to measure. Put the DDM in the 20V range...

http://www.geofex.com/effxfaq/fxfaq.htm
https://www.diystompboxes.com/pedals/debug.html
https://www.diystompboxes.com/cnews/FAQ.html

nokaster · Post by **nokaster** » 21 Oct 2007, 23:12

ok...

i'm a dumb ass...

how easy is it to put the germanium transistors in the sockets the wrong way?
VERY EASY...

but... my guitarsignal doensn't come through the circuit now and when i touch the input cap, there is a loud crackle... so something is wrong there!

i do hear the massive oscilation when i turn the pots and the pots don't crackle anymore. so output of the circuit seems OK.

there is something wrong with the circuit input... but what...

bajaman · Post by **bajaman** » 21 Oct 2007, 23:40

voltages and pictures

bajaman

DougH · Post by **DougH** » 22 Oct 2007, 11:55

Did you replace the transistors with known good ones? You may have blown them when they were mis-wired.

nokaster · Post by **nokaster** » 23 Oct 2007, 20:48

i'm sorry guys, but i have put this project on hold for now...
mostly because it was messy to begin with...
i'm gonna redo the whole thing as soon as i get some more transistors.

i've worked on my woolly mammoth today.
the components are soldered on the stripboard and it isn't messy this time.
and i've drilled the enclosure! bought a multibit and it worked fabulously.
tomorrow or the day after my gf and i will do all the wiring and than we'll test this one... hopefully the mammoth it will come alive right away.

i really want to thank you for the help! i have a lot to learn about electronics!

bajaman · Post by **bajaman** » 23 Oct 2007, 23:58

i really want to thank you for the help! i have a lot to learn about electronics!

Ask anytime you need any help - we are only too happy to offer any assistance we can, to help you complete a successful build.
By the way, my first build didn't work properly - I can still remember the satisfaction I experienced when I built something that actually worked properly the first time

Good luck with the Mammoth - hope it works well for you
Cheers
bajaman

nokaster · Post by **nokaster** » 24 Oct 2007, 19:06

because my gf didn't feel like soldering today, we didn't work on the mammoth, but i wanted to do at least something...

so once again i took the fuzz factory to the table, connected amp and guitar AND for the first time i used a battery instead of the boss PSA230...

low and behold: it works!!!!
it fuzzed, it squeeled, it oscilated, it buzzed, it fuzz factoried...

away with that battery and in with the adapter...
it still works and does all the above...

how in the name of god is it possible...
neither me nor you will ever know what the problem was in the first place...
it kinda solved itself!

i have to work a little on the grounding, but that can't be hard...
it just is what it is... a working fuzz factory!

and i'm happy! but i can't say that i trully love this pedal yet...
it's really tricky to operate.

i don't know what else to say, except, thx for the help! i think you guys thinking about it telepatically cured it or something along those lines

analogguru · Post by **analogguru** » 24 Oct 2007, 19:17

i think you guys thinking about it telepatically cured it or something along those lines

No we only helped you to plug the Boss-adapter into the AC-outlet

enjoy your built,

analogguru

bajaman · Post by **bajaman** » 24 Oct 2007, 19:42

No we only helped you to plug the Boss-adapter into the AC-outlet

but seriously, you may need to try some decoupling if using a power supply other than a battery ( connect a 47 ohm resistor in series with the +ve dc input, followed by a 100uF electrolytic to ground - take your supply to the circuit from the junction of the resistor and capacitor).
Cheers
bajaman