The Erupter™ fuzz started as something I wanted just for myself - the ultimate classic fuzz tone. One with a simple, yet effective control interface and that works anywhere in the signal chain. A fuzz with a big low end, but not too mushy, a biting top end without being too harsh, and just enough output to politely send a tube amp over the top. It must also have excellent wide-range clean up with the guitar’s volume control without losing too much low end. It took a long time and a lot of experimenting to get there but I think I finally nailed it.
A lot of people think this classic circuit is a no-brainer due to its low parts count, but I beg to differ. Since there are so few parts in the circuit, everything makes a difference. That’s why you see so many variations on the market today. You can use the topology, but the sound always varies. I’ve made plenty of designs based on this circuit in the past, but none of them gave me the perfect, overloaded-yet-refined full-force fuzz tone with crushing lows, smooth top end and an input that is responsive through the full range of the guitars volume control without losing too much low end in the process. Until now!
I spent almost two years swapping transistors, measuring resistors, adding controls, removing controls, trying all types and values of capacitors, and basically using every trick I ever learned. What I landed on is exactly the sound I had in my head - the perfect crushing fuzz tone.
I managed to whittle down the controls to the most important one of all, Bias. Why leave out the volume and fuzz controls? Most people leave the volume and fuzz all the way up, at least that’s the way I always do it. This yields the thickest fuzz and the level is slightly above unity to push the full frequency range of the guitar out front when you kick it on. By setting these at maximum and allowing control over the bias, you can freely adjust the character of the fuzz for more tonal variations.