As a first pedal build I put together a Silicon NPN Fuzz Face clone following this schematic: http://fuzzcentral.ssguitar.com/fuzzface/fuzzfacenpnschematic.gif
So I put it all together But when I plugged it in to test it all I get is a hum. If however I put my finger on the point where the negative of the 9V battery is soldered to the ring I get the a clean guitar sound coming through the under but still under the loud hum. There doesn't seem to be any fuzz and the fuzz pot doesn't change anything, onl the volume does.
I wasn't sure about what to connect the input and outputs to so that might be the start of the problem.. anyone?
Casey
(http://www.luciferstrip.com/fuzz/debug.jpg) (http://www.diystompboxes.com/smfforum/index.php?topic=29816.0)
to help, we'll need, at bare minimum, the transistor voltages (hopefully you have a meter)...and clear closeup pics will definitely give others a good chance to spot an error.
did you breadboard it first to see if it worked?
good luck
Quote from: LucifersTrip on February 20, 2012, 01:36:52 AM
(http://www.luciferstrip.com/fuzz/debug.jpg) (http://www.diystompboxes.com/smfforum/index.php?topic=29816.0)
to help, we'll need, at bare minimum, the transistor voltages (hopefully you have a meter)...and clear closeup pics will definitely give others a good chance to spot an error.
did you breadboard it first to see if it worked?
good luck
Thanks for that link, I just found this site. I'll check the voltagesme or my dad cant figure out the problem I'll come back with pics. Thanks.
just remember, whatever is wrong, you can figure it out. follow logical steps, read the guides, you can do it! if you get frustrated, take a break but keep your eye on the finished result. it is so exciting when you finally get to hear something you made yourself roar
Measured voltages
Voltage at the circuit board end of the red battery lead = 8.86
Voltage at the circuit board end of the black battery lead =0
Q1
C =8.55
B =0
E =0
Q2
C=8.7
B=8.5
E=
and just after this, I checked the voltages of the others again and they're all 0, not sure what happened. Maybe faulty meter.. but didn't manage to get emitter of Q2
Also, I changed the 20uF capacitor to a 22uf because I couldn't find a 20. And the layout of the PCB is very much thrown together according to the circuit diagram, couldn't copy one because of the sort of circuit board I used
Will upload pics when i find camera
Fix your meter.
Q1 B should be like 0.6V, not zero.
Likely causes: short near Q1 B, reversed input cap, not-really-connected 100K, or not-connected Q2 E to FUZZ pot.
Quote from: PRR on February 21, 2012, 12:30:41 AM
Fix your meter.
Q1 B should be like 0.6V, not zero.
Likely causes: short near Q1 B, reversed input cap, not-really-connected 100K, or not-connected Q2 E to FUZZ pot.
Okay, meter wasn't broken, when put across the battery it shos 8.8V, then when probing the transistors that were 8.5V or something volts before, they are now between 0 and 0.05V
As far as I can tell, all those likely causes are fine. Apart from a short near Q1 B, not sure how to tell if that's the problem
still, post all the correct voltages when you get a chance...
Quote from: LucifersTrip on February 21, 2012, 01:01:44 AM
still, post all the correct voltages when you get a chance...
Well I measured them all, but now they all appear to be 0V as if a wire came loose, but everythings exactly the same..
ok, go back to the troubleshooting guide. track every trace, test each one for correct connection, and also test for things connecting that should not connect. this is where the problems are. forget voltages for a minute til you do this. something is shorted or not connected right.
> As far as I can tell, all those likely causes are fine.
> now they all appear to be 0V
If it was "fine", it would be working and showing reasonable voltages.
Electrons are VERY fussy little things. If everything is right, they are forced to do what we built; but one little thing not-right.....
Quote from: joegagan on February 21, 2012, 04:50:26 PM
ok, go back to the troubleshooting guide. track every trace, test each one for correct connection, and also test for things connecting that should not connect. this is where the problems are. forget voltages for a minute til you do this. something is shorted or not connected right.
Checked everything for connection, but haven't tested things connecting that shouldn't be, probably the problem, thanks
Okay so the meter problem is fixed, and same measurements, VERY little voltage on the base of Q1 but not 0V as I said before. Same again, The 100K, Fuzz pot and 2.2 cap are all connected properly. I will try replacing Q1 with a new one and see what the voltage is then.
Not to be overly picky, but what's the value of the fuzzpot ?
Count the number of connections at 1 node [pick node 1 to check on], and note the polarized markings of the schematic of any components with a lead to that node.
Use the DMM to count the node connections on your board, observe polarity wherever there is a marking which 'doesn't turn around like TOT', ie if one side has an arrow or a line or a _ or a + marking...count it as as relevant as anything.
Starting at the battery clip node might be a good place, see that every node past a battery pole [note polarity] actually makes a connection to, or 'through to' the board...trace each side of the PS through whatever it goes through [shown on schematic].
Measure every resistor [they help set up/adjust DC bias], I used 470k instead of 470 in a few FF's.
Quote from: petemoore on February 22, 2012, 06:11:11 AM
Not to be overly picky, but what's the value of the fuzzpot ?
Count the number of connections at 1 node [pick node 1 to check on], and note the polarized markings of the schematic of any components with a lead to that node.
Use the DMM to count the node connections on your board, observe polarity wherever there is a marking which 'doesn't turn around like TOT', ie if one side has an arrow or a line or a _ or a + marking...count it as as relevant as anything.
Starting at the battery clip node might be a good place, see that every node past a battery pole [note polarity] actually makes a connection to, or 'through to' the board...trace each side of the PS through whatever it goes through [shown on schematic].
Measure every resistor [they help set up/adjust DC bias], I used 470k instead of 470 in a few FF's.
The fuzz pot is an A1K pot. Sorry didn't understand much of you're advice about nodes :/. I just measured every resistor and they are what they should be according to the schematic, are you recommending I need to replace the 330?
Hi Caseyf,
I made this video a few weeks back. Its part of my "how to build a guitar pedal" series of videos and is aimed at newcomers to the diy stompbox world. Its some of the troubleshooting steps i use to fixing effect problems, both wired up inside an enclosure, and circuit testing. Anyway, check it out, i hope it sets you on the path to solving the problem!
Paul
DIY Guitar Pedal Tutorial 9 - Fault Diagnosing
http://www.youtube.com/watch?v=JnD4-_Fhd90
Quote from: chromesphere on February 23, 2012, 12:49:22 AM
Hi Caseyf,
I made this video a few weeks back. Its part of my "how to build a guitar pedal" series of videos and is aimed at newcomers to the diy stompbox world. Its some of the troubleshooting steps i use to fixing effect problems, both wired up inside an enclosure, and circuit testing. Anyway, check it out, i hope it sets you on the path to solving the problem!
Paul
DIY Guitar Pedal Tutorial 9 - Fault Diagnosing
http://www.youtube.com/watch?v=JnD4-_Fhd90
Hi, thanks I probably need to watch all of them :)
Okay, I just made a completely new one, new board and components because I had spare. New boards much more neat and laid out better than the last one. EXACT same problem. Not enough voltage on the base of Q1(there is 0.1V). So if I managed to get the exact same problem when making it twice does that mean the schematic isn't correct? Like I need to change some components??
Quote from: caseyf on February 24, 2012, 01:46:39 AM
Okay, I just made a completely new one, new board and components because I had spare. New boards much more neat and laid out better than the last one. EXACT same problem. Not enough voltage on the base of Q1(there is 0.1V). So if I managed to get the exact same problem when making it twice does that mean the schematic isn't correct? Like I need to change some components??
that schematic is good, so sadly, it seems you're making the same mystery mistake as before.
I just realized (unless I missed it) that you haven't told us what transistors you were using...or whether you measured their gains.
...and we still need all voltages for both transistors....and of course, pics always help.
good luck
Okay when plugged in now, theres a harsh fuzz sound when the strings are strummed really hard.
Quote from: LucifersTrip on February 24, 2012, 03:00:52 AM
Quote from: caseyf on February 24, 2012, 01:46:39 AM
Okay, I just made a completely new one, new board and components because I had spare. New boards much more neat and laid out better than the last one. EXACT same problem. Not enough voltage on the base of Q1(there is 0.1V). So if I managed to get the exact same problem when making it twice does that mean the schematic isn't correct? Like I need to change some components??
that schematic is good, so sadly, it seems you're making the same mystery mistake as before.
I just realized (unless I missed it) that you haven't told us what transistors you were using...or whether you measured their gains.
...and we still need all voltages for both transistors....and of course, pics always help.
good luck
Okay so i changed the input from stereo to mono and now its giving me fuzz, but only when I pluck really loud. So the circuits working but theres not enough gain going into the transistors I'm assuming.
Transistors are BC183L and I havnt measured their gains?
Voltages:
Q1
C 8.7
B 0.1
E 0.2
Q2
C 8.8
B 8.7
E 0.2
You need to post pictures. The sooner you post pics the sooner everyone can figure what's wrong.
Sorry about them being super big, tell me if these angles are useless or not and if so what pics would be helpful.
(http://i42.tinypic.com/20thrab.jpg)
(http://i39.tinypic.com/scewdv.jpg)
HOLD UP A SECOND... I read a datasheet that said bc1873Ls are CBE when looking at the flat side.. I have reason to believe that they are in fact ECB??
Switched the transistor pins, assuming they are in fact ECB, but the sound is exactly the same? only get sound when strum the @#$% out of the strings still.
Voltages now:
Q1
C 8.7
B 7.9
E 8.5
Q2
C 8.9
B 8.7
E 8.5
Now that I know the pinout is ECB.. the gains of the transistors are 480 and 321
Quote from: caseyf on February 24, 2012, 07:04:38 AM
Switched the transistor pins, assuming they are in fact ECB, but the sound is exactly the same? only get sound when strum the @#$% out of the strings still.
Now that I know the pinout is ECB.. the gains of the transistors i have are 480, 300 and 321
pardon my french.
there is a whole bunch of shit shorting out over here, go back to what ( me and a bunch of other guys) said 3 days ago.
trace your freaking circuit, you have shit touching that should not be touching.
Quote from: joegagan on February 24, 2012, 06:01:04 PM
pardon my french.
there is a whole bunch of sh*t shorting out over here, go back to what ( me and a bunch of other guys) said 3 days ago.
trace your freaking circuit, you have sh*t touching that should not be touching.
Are you saying that from the picture or just assuming? I assure you none of the parallel tracks are connected with bridges or anything despite what it looks like in the photo. So by sh*t touching do you mean things actually put in the wrong places and connecting to the wrong things?
i did not study the picture.i looked at your posts and voltage readings. not trying to be an ass, just telling you, you have something touching where it should not. or something not hooked up.
you are very close to finding the answer, it is in you, not us.
Quote from: joegagan on February 24, 2012, 07:18:03 PM
i did not study the picture.i looked at your posts and voltage readings. not trying to be an ass, just telling you, you have something touching where it should not. or something not hooked up.
you are very close to finding the answer, it is in you, not us.
You're not being an ass, I appreciate your help. Thanks I'll scrutinize the @#$% out of it. in process of testing with the meter what every single pin of every component is and isnt connected to.
Quote from: caseyf on February 24, 2012, 07:46:39 PM
Quote from: joegagan on February 24, 2012, 07:18:03 PM
i did not study the picture.i looked at your posts and voltage readings. not trying to be an ass, just telling you, you have something touching where it should not. or something not hooked up.
you are very close to finding the answer, it is in you, not us.
You're not being an ass, I appreciate your help. Thanks I'll scrutinize the @#$% out of it. in process of testing with the meter what every single pin of every component is and isnt connected to.
PS, could any of the caps or anything be ruined from having the transistors in the wrong way all this time?
not likely.
the highest chance of bad component would probably be a transistor since you've resoldered em numerous times, but if you got gains as you noted, they're probably ok.
it's difficult to check if everything is ok from a vero (especially since I never used vero), but it'd be easier if you posted a layout you used...if indeed you did use one. here's one:
http://media.photobucket.com/image/recent/philbinator1/Fuzzfacesilicon.gif
one last note...if you have the transistors out, place the higher gain one in the Q2 spot...when you get it working, it'll probably sound better.
Quote from: LucifersTrip on February 24, 2012, 08:25:54 PM
the highest chance of bad component would probably be a transistor since you've resoldered em numerous times, but if you got gains as you noted, they're probably ok.
it's difficult to check if everything is ok from a vero (especially since I never used vero), but it'd be easier if you posted a layout you used...if indeed you did use one. here's one:
http://media.photobucket.com/image/recent/philbinator1/Fuzzfacesilicon.gif
one last note...if you have the transistors out, place the higher gain one in the Q2 spot...when you get it working, it'll probably sound better.
I didn't use a layout as I couldn't find one suitable to my board (the one you posted would have perfect perfect if only I'd found it). I could draw mine up if that would help. Everything is connected to what is should be and not connected to anything else on the circuit board. I literally just checked every single pin with every single other pin. Nothing missed. I'm wondering whether it's my caps, I'm not 100% the 0.01 is actually 0.01uF, and the 20uF is replaced with a 22uF. The voltages of the caps don't matter right?
your caps are plenty big enough, i think.
just so you can have a win and get excited about this whole hobby again, try building the whole thing again ( you have a big old perfboard there). re-use parts if you have to but preferably leave the current one as-is so you can check it later when you are more adroit.
I just changed the input from mono to stereo AND ITS WORKING. @#$% YESSSS. only thing now is theres a really high pitched frequency in the background when i play, and when the volume and fuzz are both on full there is an extremely evil sounding staticky feedback thats unbearable. any thoughts on how to remove these?
Those are the consecuences of messing with a Si FF! You'll have to place a small cap, 100p for example, between C and B of transistor n°2. This will roll off some highs. If squealling doesn't disappear, try a larger cap, 150p, 220p, and so on. Start with 47p, high values roll off more highs.
Quote from: slideman82 on February 24, 2012, 09:50:11 PM
Those are the consecuences of messing with a Si FF! You'll have to place a small cap, 100p for example, between C and B of transistor n°2. This will roll off some highs. If squealling doesn't disappear, try a larger cap, 150p, 220p, and so on. Start with 47p, high values roll off more highs.
K, thanks ill do that. it works perfectly with a Hot dot box (pre amp/boost) before it however. without that the fuzz fizzles out while the clean singles keeps sustaining
congrats, you are welcome and all that. remember, i told you 3 days ago you would get it?
you done good kid, now, thank your elders.
Haha sorry got a bit carried away, thank you thank you all who helped. But see, it wasnt a shorting problem in the end ;)
Quote from: caseyf on February 24, 2012, 10:00:19 PM
Quote from: slideman82 on February 24, 2012, 09:50:11 PM
Those are the consecuences of messing with a Si FF! You'll have to place a small cap, 100p for example, between C and B of transistor n°2. This will roll off some highs. If squealling doesn't disappear, try a larger cap, 150p, 220p, and so on. Start with 47p, high values roll off more highs.
K, thanks ill do that. it works perfectly with a Hot dot box (pre amp/boost) before it however. without that the fuzz fizzles out while the clean singles keeps sustaining
cool...now it's time to adjust the bias to get it right on.
Did you make note of the voltages when it started working? It'd be a good idea...
Pull the 8.2K and substitute a pot (20K+) there and adjust until you get Q2 C to around 4.5-5.5v
The fuzz probably won't fizzle out anymore.
btw, any clue why it worked after you changed the input from mono to stereo? it should work either way if you use the right lugs.
but, stereo is preferable since you will be using it as a switch for the battery.
Quote from: LucifersTrip on February 24, 2012, 11:48:44 PM
Quote from: caseyf on February 24, 2012, 10:00:19 PM
Quote from: slideman82 on February 24, 2012, 09:50:11 PM
Those are the consecuences of messing with a Si FF! You'll have to place a small cap, 100p for example, between C and B of transistor n°2. This will roll off some highs. If squealling doesn't disappear, try a larger cap, 150p, 220p, and so on. Start with 47p, high values roll off more highs.
K, thanks ill do that. it works perfectly with a Hot dot box (pre amp/boost) before it however. without that the fuzz fizzles out while the clean singles keeps sustaining
cool...now it's time to adjust the bias to get it right on.
Did you make note of the voltages when it started working? It'd be a good idea...
Pull the 8.2K and substitute a pot (20K+) there and adjust until you get Q2 C to around 4.5-5.5v
The fuzz probably won't fizzle out anymore.
btw, any clue why it worked after you changed the input from mono to stereo? it should work either way if you use the right lugs.
but, stereo is preferable since you will be using it as a switch for the battery.
Q1:
C 1.1
B 0.38
E 0ish
Q2:
C 3.6
B 1.1
E 0.7
Okay thanks I'll look for a pot. do you mean like a trimpot or an actual normal pot? And yeah, because I had the sort of jack where when you put a plug in the shield is disconnected from everything (so the -9v went nowhere?) It clearly isnt the right sort of plug for an effect pedal. How does a pot replace the resistor btw? since it has 3 pins?
Quote from: caseyf on February 25, 2012, 03:01:55 AM
Q1:
C 1.1
B 0.38
E 0ish
Q2:
C 3.6
B 1.1
E 0.7
since Q2 C is low, you will get a thinner tone with less volume and not as good sustain
Quote
Okay thanks I'll look for a pot. do you mean like a trimpot or an actual normal pot?
either one...many prefer a permanent normal pot since the bias will change with temperature...and you'll want to make slight adjustments when you play
QuoteHow does a pot replace the resistor btw? since it has 3 pins?
it is just a variable resistor when using 2 pins (middle and either side). in your case, looking down with lugs forward, use the middle and right. full counterclockwise = 0K
Quote from: LucifersTrip on February 25, 2012, 05:48:34 AM
Quote from: caseyf on February 25, 2012, 03:01:55 AM
Q1:
C 1.1
B 0.38
E 0ish
Q2:
C 3.6
B 1.1
E 0.7
since Q2 C is low, you will get a thinner tone with less volume and not as good sustain
Quote
Okay thanks I'll look for a pot. do you mean like a trimpot or an actual normal pot?
either one...many prefer a permanent normal pot since the bias will change with temperature...and you'll want to make slight adjustments when you play
QuoteHow does a pot replace the resistor btw? since it has 3 pins?
it is just a variable resistor when using 2 pins (middle and either side). in your case, looking down with lugs forward, use the middle and right. full counterclockwise = 0K
Thank you thank you the 20K pot makes all the difference, pity I got a a trimpot and not a normal one, didn't realise it would shape the sound so much. Ohwell I can always change. absolutely love my fuzzface, just need to box it up now :)
Quote from: caseyf on February 26, 2012, 04:01:46 AM
Thank you thank you the 20K pot makes all the difference
excellent..one more fuzz in the world
Quote
pity I got a a trimpot and not a normal one, didn't realise it would shape the sound so much. Ohwell I can always change. absolutely love my fuzzface, just need to box it up now :)
drill a hole in the bottom of the box right above the trimmer...ahhaah
good luck
excellent..one more fuzz in the world
Quote
excellent..one more fuzz in the world
new sig
Quote from: rousejeremy on February 26, 2012, 10:13:27 PM
excellent..one more fuzz in the world
Quote
excellent..one more fuzz in the world
new sig
haha..thanx...don't forget to capitalize the "T"
Quote from: rousejeremy on February 26, 2012, 10:13:27 PM
excellent..one more fuzz in the world
Quote
excellent..one more fuzz in the world
new sig
*2 more fuzzes in the world I made one as a present too ;)
Still have a horrible high pitched staticy sound, when i roll off the volume the signal cleans up but theres theres still that staticy sound thats about the same volume as the clean signal. and also it has good tone with the fuzz on full but this causes an extremely peircing screeching sound while not playing. No small caps have taken away either the staticy background noise or the feedback. any suggestions? Is this because of the high gains of the transistors? (300 and 320 in one pedal and 660 and 640 in the other)
It will pitch with every silicon transistor, I think, that's my experience. Which caps have you placed?