RO 1-Tube 12V Guitar Preamp PUBLIC

Richter Original 1-Tube 12-Volt Guitar Preamp

Richter Original 1-tube 12-volt experimental guitar-preamp circuit. Controls Include: Input Level, Fuzz enable switch, Fuzz symmetry switches, Fuzz Depth, Bass, Treble, Drive, and Volume. Circuit is based on the output section of a Garnet H-Zog distortion unit but using a single 12AL8 triode + tetrode tube with an added shunt-type Schottky-diode clipping-array (for fuzz), a passive 2-band Baxandall tone control, and an output transformer made specifically to replace that of a Fender Champ. Experimental circuitry. Untested design. No simulation. Frequency response and overall gain must be discovered during breadboard testing. The advantage is that the tube was designed for relatively safe +12VDC supply-voltage on the plates AND heater (originally from a car battery), instead of the dangerous high voltage typical with standard vacuum-tubes. Note: The sound of the completed circuit cannot be predicted theoretically and must therefore be determined experimentally. But expect it to sound like a boutique single-ended low-wattage guitar-amp.
The tube is available at The Tube Store. https://www.thetubestore.com
The output transformer is available at DigiKey. https://www.digikey.com
An 8-ohm 10-watt resistor is at Parts Express (part # 004-8). https://www.parts-express.com
A ready-made off-the-shelf 12-volt power-supply is available at the AdaFruit website. Get the 12V DC 1000 mA Regulated Switching Power Adapter, Product ID: 798. https://www.adafruit.com