Problem on Boutique Fuzz

[kaboom]

Hello there, I built a boutique fuzz using this PCB and components:http://membres.multimania.fr/davpseudo/ffactorx.htm
The problem is it doesn't sound.Which is a big problem, isn't it?. I have replaced the AC128 with AC188.What makes me crazy is that when I tested it it worked perfectly(amazing sound by the way).I had it connected without a switch(i.e., jack in>PCB in>out>jack out) and worked great, but when i put on the switch it didn't work.You may think it's a wiring problem,but it's not, because I tried it again without the switch and it wasn't working!.The only different thing I noticed is that when I am replacing the battery(I've tested 3 new quality batteries) it doesn't sound,I mean, if you change the battery while the stompbox is ON you should hear some "pops", right?.
I have the negative of the battery to the jack in(stereo).I did some check with my testers,and all the soldering are right...what could it be?

If I have to check some voltages just tell me. I checked the batteries and the three of them are at 8.8v The battery clip works fine.
I hope you can help me!

[KrazyKarl]

I've had this kind of problem before. Sometimes, I'd wire the switch and it wouldn't work even after I took the switch out. What had happened was that I didn't ground the circuit when it was bypassed on the switch. Look up how to wire the switch, because I did it with logic in my head and I left that out. Then when I took the switch out, I happened to touch the back of the circuit and it made a big pop and started working, as if there was some charge that just had to get out to keep working. Not exactly sure why, but it worked. When you wire it up again, make sure the circuit gets properly grounded both when it's in use and when it's bypassed. Hope this helps.

[petemoore]

http://www.diystompboxes.com/smfforum/index.php?topic=29816.0

[kaboom]

These are the voltages I get

q3
e 0
b 0.58
c 0

q2
e 2.19
b 2.05
c 2.19


q1
e 0.73
b 0.5
c oscillates from 0.57 to 0.63,but most of the times it's at 0.60

[Bad Chizzle]

Hi,

Hoping I can help in some way I thought I'd pop in and say that it's almost a sure bet that you wired you switch incorrectly and damaged something. I did that the other day, and man was I pissed about it! But I was lucky and I didn't do any damage. So, I would  say, go through your circuit a section at a time with a signal tester and find out where you stop getting sound. Move through like this and resolve your parts problems. as you go. Then, when you get it working again without your switch, check out how your switch works with a tester, then rewire it if needed. This would be my method if I was debugging. I hope I have helped in some small way!

Chuk

[petemoore]

  lINK Doesn't work...
I assume it's a tonebender ?
  Without knowing the circuit/polarity of power supply and transistors, pretty hard to tell.
  suspects from vague business...power supply is wierd/reversed, transistor isn't oriented correctly, something got missed somehow...bout all I can offer UTCircumstances.

[jkokura]

Link worked for me. Looks like it's a Fuzz Factory clone.

The voltage your getting on Q3 makes me think something is wrong on the board. Either you've got some sort of ground, cold solder joint, or perhaps a wrong componant in there. Go over and triple check your part values and orientation. Closely inspect all the solder to make sure there are no bridges, and then start checking for poorly soldered parts.

Jacob

[kaboom]

@Bad Chizzle
I'm pretty sure I wired it correctly, because I did a SHO clone with the same wiring pattern and it works(still working heh) fine.

@petemoore In my first post you can see the link instead, search in google "Tutorial de la fuzz factory" ; it's the first link

@jkokura
As I said in my first post, it worked fine until I wired it to the 3PDT , so i think it's not a problem with part values. I think it could be the transistors orientation. I've checked every pad and everything's connected fine so i think i can say it's not cold solder joint. The only thing I have is that,when I did it the very first time it didn't sound, but when I changed the battery I could hear some ground pops(I changed a tranny and  it suddenly started working hehe).But now even if I change the battery and touch with my fingers the battery pad I can't hear any ground pop.

[Schappy]

kaboom,

Has this layout been verified?
There is a whole project file of this pedal on the "other" forum.

Your voltages are off so try to figure out why.
Build an audio probe and probe through the circuit.
Read the debugging page.

Where did you get your transistors?
Did you check for leakage?

[kaboom]

The layout is verified, because it worked before xD. And also some people from other forum did it and worked for him.
What's an audio probe?.
About the transistors spanish store.But as I told, it worked

[Schappy]

You really need to test your transistors for leakage for best performance in a fuzz face.
R.G. has a tutorial on exactly how to do this.
Or you could buy a matched set from smallbear where the homework is already done for you.


This is how you build an audio probe.
http://www.diystompboxes.com/wiki/index.php?title=Debugging

Build the enhanced version it requires less parts.
Buy an enclosed jack. Solder a .1uf cap to the hot lead and solder a wire with an alligator clip attached to the sleeve(ground).
Put the clip on your input jack ground. Insert the cable from your guitar into the input jack and insert your output cable into the probe jack. Probe through the circuit with the capacitor while strumming your guitar. Start at the input.
You can hear your guitar signal if everything is working properly.

When the signal stops or doesnt sound right you know where a problem lies.

I had a heck of a time debugging circuits until I started using the audio probe. Its a must.

[Schappy]

Or you can purchase a audio probe(signal tester)

http://www.buildyourownclone.com/probe.html

[kaboom]

There's something I don't understand.
First, to set things clear, Is battery Neccessary? I think so
Second, If I understood it right, The input is normal,i.e. The jack input goes directly into the input of the PCB
Third.About ground connections.Should I just solder the three wires together(I don't have alligator clip either)? I mean, ground of the input goes directly to ground of the pcb and ground of the pcb goes directly to ground of the out.
Then,the "only" thing I need(until a buy new parts) is to attach a .1uF(100nF,right?) cap to the hot lead of the jack out and use a (small) cable to test around the circuit right?
About the potentiometers: Should they all be at 0, maximum, or any value will work?

Can I use a normal female jack(the ones used in every stompbox)?

[Schappy]

Your guitar cable goes into input jack for your circuit.
The alligator clip is clipped to the ground lug of that same jack.

Your output cable is connected to your audio probe jack.
The capacitor is soldered with one lead on the hot lead and one bare lead to probe the circuit.
Solder a wire to the ground lug then solder a clip to the other side of the wire.

An enclosed jack will prevent metal to metal contact so it is better but you may be able to use a normal jack.

Do a search for star grounding(everything grounded at the input jack).

[kaboom]

I have this ground circuit:
                     PCB Ground
                        |
Input jack------------------Output Jack
    |
  Negative side of the battery

Is that right?

[kaboom]

Okay, this is what I get:


In 1, and 2, sound goes dooown.Works perfect before.The only thing is that in 1 sound gets distorted.On 3 the sound gets a BIG boost.

I didn't test after those pads, but overall, it sounded very bad and very low

[Schappy]

You need to start probing at the input which is the far right of your pcb image.

Since a PCB image is reversed it would be on the far left of the layout.

Look at the schematic(check the link I gave you) and follow the circuit from input to output.

[kaboom]

I checked the input,it works great.Then,after the first polarized cap,still ok(same sound).Everything's perfect until I get to 1 or 2.I checked up of the first cap(the pad just to the left of 1) and it didn't sound well,it just sounded very low

[Schappy]

Point 1 is the collector of the 2n3904 transistor. The signal you had at your input should now be amplified. If not check your pinout and soldering. Maybe the transistor is bad.

If it does boost the signal move on to the next component. If it doesnt sound right then you have to check soldering.

Point 2 is the emitter going to ground. You should not hear anything hear.

You should have a weak signal at the base and amplified signal at the collector(point 1).

[jkokura]

@jkokura
As I said in my first post, it worked fine until I wired it to the 3PDT , so i think it's not a problem with part values. I think it could be the transistors orientation. I've checked every pad and everything's connected fine so i think i can say it's not cold solder joint. The only thing I have is that,when I did it the very first time it didn't sound, but when I changed the battery I could hear some ground pops(I changed a tranny and  it suddenly started working hehe).But now even if I change the battery and touch with my fingers the battery pad I can't hear any ground pop.

Sorry to say, but part of the thing about debugging is often going back to things you 'think' have nothing wrong with them and rechecking again and again. It's like the old axiom that 'you'll always find something in the last place you look." When looking for my wife's phone the other day, the only place we were sure it wasn't was the car. After spending 2 hours looking all over, where was the phone? In the car.

It might be that the problem is not what I've suggested, but it might very well be that in double checking that you find the problem or think of checking something while you're at it.

If it was working before putting it in an enclosure, often the problem can be in the wiring or somehow the PCB is grounding itself against the case. Just another thought. Oh, and although it is possible that the switch is faulty, I usually suspect a part being faulty last. My order goes like this: Poorly installed (cold solder joint, wrong wiring), Wrong part (10k instead of 10M, 10nf instead of 100nf), Wrong orientation (sideways switch, backwards Electrolytic), bad part (faulty before installation).

Usually it's the first, but along with the next make up 90% of the debugging on new builds in my experience. Never really had a faulty part unless it was my own screwing it up, which has happened.

Hacib