RO 2-Tube 12V Guitar Preamp PUBLIC

Richter Original 2-Tube 12-Volt Guitar Preamp

Richter Original 2-tube 12-volt guitar preamp. Controls Include: Input Level, Drive, Fuzz enable switch, Fuzz symmetry switches, Fuzz Depth, Bass, Treble, Sum, Feedback Enable switch, Feedback pot, and master Volume. Employes two tubes designed to be operated using +12VDC supply-voltage (originally from a car battery) on the plates AND the heaters. Caution! High-gain circuitry. Each triode in V1 has a possible maximum gain of 20 (10 dBV), while the triode in V2 has a maximum gain of 13 and the tetrode a gain of 7, But these are multiplicative, so total possible gain for the design can be up to 35,000, though it is expected that the controls will be used to keep gains under control. One purpose, however, is to have sufficient gain to overcome the cut in signal amplitude by the diode array and tone controls while also allowing for one stage to overdrive the next. Experimental circuitry. Untested design. No simulation. Frequency response, actual gain, and the sound of the fuzz and tube distortion must be determined while breadboard testing.
The tubes are available at The Tube Store. https://www.thetubestore. The transformer is available at DigiKey. https://www.digikey.com The power-supply is from the AdaFruit site. https://www.adafruit.com