RO Experimental 3-Tube Fuzz PUBLIC

Richter Original Experimental 3-Tube Preamp With Fuzz

Richter Original 3-tube preamp circuit with 2-voice shunt-diode fuzz. Controls Include: Input Level, Bass, Treble, Notch, Fuzz 1 enable switch, Fuzz 1 symmetry switches, Fuzz 1 Depth, Fuzz 2 enable switch, Fuzz 2 symmetry switches, Fuzz 2 Depth, Drive, and Volume. Circuit is intended to provide 3 stages of overdriven-tube distortion plus two separately enabled shunt-diode fuzz effects; one from standard silicon diodes and one from Schottky diodes, where the symmetry switches determine the harmonic content of each fuzz voice. Here, the input can be overdriven using a boost or overdrive stomp-box while V2 can be overdriven by V1, depending on the setting of the Input Level control. The sound thereof will be like that of a 12AU7 dual-triode tube. V3 can be overdriven by V2, depending on the settings of the Tone controls, while V4 can be overdriven by V3 but whose output is affected by the Notch control (a simple high-cut tone-pot). The sound of V3 is described as warm, smooth, and musical, with soft attack, clear mids, and classic tone, adding richness to the signal. By contrast, V4 is bright and dynamic, with faster responsiveness, and adds both bass punch and more detail to the highs. It will also provide some edge when overdriven. The Diode Fuzz sounds should have little / no affect on overall gain, though the project is not meant to provide extreme gain; only +20 dBV overall (i.e., Vo/Vi = 10). Finally, V5 can be overdriven by V4, depending on the setting of the Drive control. If not overdriven it will be clean and articulate, emphasizing upper-mids, limiting the lows, but providing vintage tone. Overdriven, its distortion will be like that of a normal American output tube (e.g., 6V6, 6L6, etc.). Frequency Range 20 Hz to 16 kHz. Suitable for 6/7/8-string guitar or 4/5/6-string bass. Power-supply not shown. Requires a regulated single-polarity +12VDC supply providing >= 1A of current. Experimental circuitry. Untested design. No simulation. Rack-mount implementation with vibration-damping mounts is recommended. And put pads on the tubes to help mitigate vibration noise. Example Power-Supply: 12V DC 1000 mA Regulated Power Adapter, Product ID: 798. $8.95. From AdaFruit website. https://www.adafruit.com .