Build Your Own Clone Message Board

Just built my first pedal, Classic Fuzz, was great fun, anyways everything seems to work as it should except for the Fuzz knob, it does nothing when turned. The solder joints look good on the pot and all other joints seem to be ok and every component appears to be in the correct location. Is there a particular area of the circuit I can check, or how do I troubleshoot to verify the pot is functional? Any pointers would be appreciated, thanks.

The Fuzz control should have a dramatic effect on the amount of fuzz in the pedal's output, so something is definitely amiss. The first thing I would check is to make sure that you have the correct pot installed in that position--it should be the B1K, with the B10K up in the Bias position.

To check the function of the pot, disconnect power from the pedal, then use a multimeter to measure the resistance across the two outside lugs of the pot. This should give a value close to 1 Kohm. Then, turn the pot to its midpoint and measure the resistance between the left lug and the center lug. At the pot midpoint setting, this should be right around 500 ohms.

Beyond that, it would be most helpful to us for you to post a good set of photos. They should be LARGE, well-lit, well-focused shots of BOTH sides of the PCB and all of your jack & switch wiring.

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“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Thank you, I checked the restitnace as you indicated, I got around 350 ohms at the mid point, and 675 ohms when the pot is turned all the way up, resistance is definitely changing with the pot position. I will try and disassemble to get photos of the backside of the PCB. Had I known better I wouldn't have selected the internal nut on the power jack.

The red sleeve on the jack wire is just insulation Inslid over the wire as I had knicked it with the soldering iron.

I would probably assume you have faulty a solder joint on lug 1 of your fuzz pot. With lug 1 not making continuity, the fuzz would "work", but the fuzz control would not create a voltage divide, and therefore, produce little to no effect. If the fuzz is "working", this also means that the solder joints at lugs 3 and 2 should be good because this allows the 22uF to still act as the emitter bypass cap.

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*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

Thanks for the input. I had a bad solder on the negative side of the capacitor. Not sure if the PCB was faulty or if I damaged it but I could not get a joint onto the negative side of the cap. I removed it from the PCB and soldered it directly to the fuzz pot. Everything works now as it should and the pedal sounds great. My only problem now is deciding which kit to purchase next! Leaning towards the British bluesbreaker.

Thanks again

Glad to hear you got it working! Good thinking soldering that cap across the fuzz pot! You can obviously read a schematic.

Inability to get a solder joint to adhere on the PCB is most often due to the solder pad having been ripped off. This is usually caused by insufficient care in desoldering a previously installed component. Not saying you did that, but thought I would just mention that as a possible cause.

Best of luck with your next build, whichever kit you decide upon.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

What are some "workarounds" if this happens? I had it happen when I replaced a broken switch on my Divided Octave recently (see "insufficient care" above ). Unfortunately the next pad along the circuit from where the switch attached wasn't a normal solder pad, it was barely a pinhole just below a socket. I was able to make an "L" out of a clipped resistor lead and get it just barely soldered to the pinhole, the other end to the switch leg. It worked, but I wondered if there was a better way to repair a detached pad?

Timely thread- thanks!. I have the same problem with my smallbear Fuzz E-1. Everything works fine except the fuzz pot. I'll get right on it!

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Twisting and tinning is for chumps.

Without a photo, I can't be sure what this was, but I think you must have encountered a via. Vias route the signal from one side to the other of a double-sided PCB. I think you probably did the best you could with it. I imagine you could also flip the board over and see where the trace leads on the other side, and then run a wire around the edge of the board to make the connection. You could test the path of the trace using your multimeter in continuity mode.

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Scott

My band, Austin Hollow