Recent content by apierz

I ordered some more transistors with values closer to the ones in the build documentation. I got two OC140s with these values Q1: hFE=94 Ic=1.0mA Ube=132mV ICE0=28uA ICEs=12uA Q2: hFE=173 Ic=1.7mA Ube=133mV ICE0=37uA ICEs=14uA but it was very gated and fuzzy at all bias/guitar volume levels.

That would explain it. If anyone is interested in trading some Fuzz Face PNP transistors for some good NPN transistors please let me know ;)

My new transistors arrived: Q1: 2N404 hFE=109 Ic=1.2mA Ube=102mV ICE0=54uA ICEs=8uA and Q2: 2N1309 hFE=333 Ic=3.7mA Ube=185mV ICE0=0.24m ICEs=8uA When socketed, with the bias pot at noon, I can only get the trim pot to 2.2V or so and there's no fuzz whatsoever, regardless of trim/bias pot...

Yeah, I bought four hoping at least two would be close but none of them ended up being suitable. I’ve ordered a set of new transistors that’ve been pre-measured to have good values for fuzz face style pedals. I will swap those in when they arrive and report back.

With the trimpot fully clockwise and the pots at noon: Q1: E: -3.63 B: -4.55 C: -3.43 Q2: E: -3.51 B:-3.43 C: -3.50

I recently finished a build of the Tactical Fuzz. It sounds great as a fuzz, but it doesn't clean up no matter how low I set the volume on my guitar (which is my main reason for wanting to build this pedal). I couldn't find instructions for how to set the internal trim pot in the build...

Thank you both for helping on this old thread. @PJS, I never would have caught the pinout issue on that transistor if you hadn't pointed it out. I was able to switch the source and gate pins and use @Jeffrey 's advice to set the trimmer and now it's working great. It's definitely a finicky...

SOLVED: For Q2 I was using a through hole K30A transistor which uses a pinout that does not match the placement of the holes on the pcb and so I had soldered this part incorrectly. After correcting my mis-soldering, I used this method from @Jeffrey to set the trimmer pot and get the pedal...

You may have a bad Gain Pot, you wouldn't be the First From what I understand of how the circuit works it blends in the clipped signal with a clean signal with the dual gang gain pot controlling the ratio. The more CCW the pot the more clean signal and the more CW the pot the more clipped...

I got forward voltage of .32 and .31.

You are right, I misreported pin 4 on IC 2 and missed the minus sign. It is reading as -8.40v. Continuity test results on IC2: 1&2: no 2&3: no 3&4: no 4&5: no 5&6: no 6&7: no 7&8: no 8&1: no I did the other TL072 as well: 1&2: yes 2&3: no 3&4: no 4&5: no 5&6: no 6&7: no 7&8: no 8&1: no

Here are the voltages I recorded off the ICs starting from the one closest to the jacks and going down towards the footswitch. Pins are numbered starting with top left and going counterclockwise. IC1: 1. 8.89 2. 4.66 3. .004 4. 4.03 5. 8.38 6. 3.98 7. 5.49 8. 8.88 IC2: 1. 4.45 2. 4.47 3...

I haven’t had a chance to work on it yet. I’ll probably be able to do the recommended testing on it later today.

Yeah it seems like nothing is happening on the “gain” side of the mix and turning the drive knob counterclockwise makes it louder which is leading me to think the problem is at least partially in or more of the op-amps. Wouldn’t be the first time I wrecked an IC. I needed more TL072s for...

Thank you for the suggestion. Yes, I did use the included footswitch board. I tested continuity on each wire between the main board and the footswitch board and got a tone on the DMM for each of them so it looks like the footswitch is properly connected at least.