RO 4-Stage Tube + Diode Fuzz PUBLIC

Richter Original 4-Stage Tube Preamp With 2-Voice Fuzz

Richter Original 4-stage tube preamp circuit with 2-voice shunt-diode fuzz. Controls Include: Input Level, Bass, Mid-Center, Treble, Drive, Fuzz 1 enable switch, Fuzz 1 symmetry switches, Fuzz 1 Depth, Fuzz 2 enable switch, Fuzz 2 symmetry switches, Fuzz 2 Depth, and master Volume. Both specified tube types were designed to work using a single +12VDC supply voltage on plates and heaters (originally a car battery). Note: The 12U7 dual triode (not 12AU7) has no other part number. Do not substitute with any other tube for the 12U7. The 12EA6 does have substitutes, including 12EK6 and 12DZ6. Both tube types are available at The Tube Store. https://www.thetubestore.com This design is not intended to provide much gain but rather to deliver overdriven tube sound like that of an American-made boutique guitar amplifier, with two separately enabled shunt-diode fuzz voices; one from standard diodes and one from Schottky diodes. Note: The symmetry switches (SSw) set the harmonic content of the fuzz. Note: For tube distortion, the input can be overdriven by a boost or overdrive stomp-box; Q1 can overdrive Q2, while Q3 can overdrive Q4, depending on control settings. Power-supply not shown. Example Supply: 12V DC 1000 mA Regulated Switching Power Adapter, Product ID: 798. $8.95. From AdaFruit website. https://www.adafruit.com