The Electric Prunes - I Had Too Much to Dream (Last Night) (1966)
I based the fuzz circuit off the Maestro Fuzz-Tone: a very early fuzz circuit built by Gibson in the 60's. The tremolo is an opto-coupled phase-shift oscillator design which I adapted from a vintage guitar amplifier.
I happened to know somebody who had in their possession an original Fuzz-Tone FZ-1B pedal, which I was lucky enough to borrow for a while to use as a basis for my design. There was even a schematic included inside the case!
The original FZ-1B schematic diagram. Notice the error at Q4 which was corrected in red pen!
This is a very straightforward fuzz - the two controls are volume and balance, which sort of blends the buffered output with the fuzz (I personally did not find this to be very useful). In my final design I have removed the blend knob. There are a number of different revisions of this schematic floating around on the internet, each version making some rather significant changes.
The original FZ-1B uses unmarked TO-106 NPN silicon transistors. By taking some voltage readings with my multimeter I estimate the beta of these devices to be around 45, which is quite low for a silicon transistor.
After prototyping on breadboard, I began to construct my schematic and PCB artwork in Altium. I prefer to mount as many components as possible to the PCB to keep the enclosure looking clean and free from wires introducing any unwanted noise. I also normally do all my ground connections on a ground plane to reduce noise, but for some reason Altium was not having a bar of that in this project (I have to use this software for projects at university, but I'm still getting used to the many ins and outs of it).
I decided to use some 2N2222A transistors, as I happened to have some handy. The fuzz sounds very similar to the original unit, but has a quite a bit more sustain (the original fuzz has a more 'gated' sound, which I would attribute to the biasing of the lower beta transistors). The diode in the 'squelcher' circuit is a vintage Japanese silicon diode. I experimented with a few different diodes to find which sounded best.
By tweaking the component values I was able to improve the range of my tremolo to around 5-15Hz. It is difficult to obtain a large frequency range from a phase-shift oscillator due to stability issues, but I have found that they sound much better than using a simple 555 square-wave oscillator.
I've used a 1590B style enclosure to house the circuit, and as you can see everything fits quite well inside the case.
| Model | Power Supply | Transistors |
| FZ-1 | 3V | 3 x Ge PNP |
| FZ-1A | 1.5V | 3 x Ge PNP |
| FZ-1B | 9V | 2 or 4 x Si NPN |
The original FZ-1B uses unmarked TO-106 NPN silicon transistors. By taking some voltage readings with my multimeter I estimate the beta of these devices to be around 45, which is quite low for a silicon transistor.
After prototyping on breadboard, I began to construct my schematic and PCB artwork in Altium. I prefer to mount as many components as possible to the PCB to keep the enclosure looking clean and free from wires introducing any unwanted noise. I also normally do all my ground connections on a ground plane to reduce noise, but for some reason Altium was not having a bar of that in this project (I have to use this software for projects at university, but I'm still getting used to the many ins and outs of it).
By tweaking the component values I was able to improve the range of my tremolo to around 5-15Hz. It is difficult to obtain a large frequency range from a phase-shift oscillator due to stability issues, but I have found that they sound much better than using a simple 555 square-wave oscillator.
I've used a 1590B style enclosure to house the circuit, and as you can see everything fits quite well inside the case.
Fuzz all boxed up - I can only just fit all my components.
For the volume and tremolo speed knobs I have used some clear-shaft potentiometers. I was able to mount these to the copper-side of the PCB, allowing them to function as standoffs for the circuit board, the chassis serves as a jumper for ground connections and the shafts also function as the indicators for bypass mode and tremolo rate. I then sanded and polished the case to get a nice mirror finish.
Shiny.
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