Hello all, I have recently been trying to build a fuzz effect circuit to use with an instrument. I have had great difficulty in building one though, although I have also built a few oscillators and an active LPF with resonance, but of course, I initially ran into issues with those too. The difficulty I have encountered throughout the 4-6 builds I've tried have been the same with this one though: just hum/buzz, controllable by the pots.

The input signal does not go through, when I tap the tip of the input's 1/4" cable, there is no response. I don't know where I am going wrong at this point, so I would like to see if anyone with the right knowledge could assist me on fixing my latest build, which by far is the simplest fuzz I could find. The schematic is posted below and I have made a video of my build and tried walking through how I put it together. If any more information needs to be provided, please ask. I followed the exact parts on the schematic, so those are what I used. I would greatly appreciate any help that could be provided, and I thank you all for your time.

Original Schematic

 

You failed to mention the 100k resistor from collector to +9V. Perhaps an oversight in your description, but I do not see the resistor on your breadboard.


FYI

 

The 100K resistor appears to be awfully close to touching the leads of the input capacitor. Make sure they are not touching.

Also, go back to the battery. 7V is fine and typical of a 9V battery. Using a power supply injects a ton of noise and this circuit is too simple to eliminate that kind of noise.

I don't see anything else but if it was me, I'd double and triple check the pinout of that transistor. It's very easy to get wrong. In fact I'd maybe build a little circuit to test it. Put an LED and a 1K resistor in series with the collector, emitter to ground, and then touch the base with a 10K resistor. The LED should light. The values of the resistors are not critical, anything within 2X would be fine.

 

Well everyone, thanks to your advice, I got it to work! the fix was quite simple, iONic pointed out a 100k resistor should be going from 9v to collector...I had it going from 9v to base, to which it immediately started to work after switching spots. I can't believe it, being my first build using transistors, I almost convinced myself that transistors were my enemy for a minute haha! Also yesterday while troubleshooting, I found one of the pot terminals had been wired wrong too, so that could've also been a part of it. From this I've learned to scrutinize more over the circuits I make, the schematic is really my best friend. I'd also like to thank you wayneh, your advice will certainly help with the optimization of the coming circuits I build, and with troubleshooting those as well. I'd like to thank everyone again, and hope you all have a nice day.