RO Tube-Sovereign Preamp PUBLIC

Richter Original "Tube-Sovereign" 5-Stage Guitar Preamp

Richter Original "Tube-Sovereign" 5 tube-stage guitar-preamp with shunt-diode fuzz and 2-band passive Baxandall tone. Controls Include: Input Level, Fuzz enable switch, Fuzz symmetry switches, Fuzz Depth, Drive, Intensity, Bass, Mid-Center, Treble, and Volume. All tubes were designed to be operated using a single +12VDC supply-voltage (originally from a car batter) on plates AND heaters. All tubes are available online at The Tube Store. https://www.thetubestore.com . Overall Frequency Range 20 Hz to 16 kHz. Suitable for 6/7/8-string guitar or 4/5/6-string bass. Overall Gain = +20 dBV (Vo/Vi = 10). Experimental circuitry. Untested design. No simulation. The 12U7 was designed to work and sound like a 12AU7 at high-voltage, with the same gain (mu = 20), though the 12U7 is a low-voltage space-charge tube (do not substitute any other tube, including 12AU7). The Input and Boost 1 Stages will sound like the front-end of a Fender "Champ" using a 12AU7 instead of a 12AX7. V3 and V4 together form a 2-stage clean-boost that should will like the front-end of a Supro 1606 "Super" guitar amplifier, though using the 12AK8 triode+tetrode instead of a 12AX7 + 6V6. V5 is used with passive Baxandall tone-control having an added Center control, where the tube will sound much like one triode from a 12AX7 but a little cleaner (lower noise), with faster responsiveness and brighter upper-mids, yet slightly less emphasis on the low-end. Will provide a vintage-style tone, even when overdriven. This project is therefore intended to sound like an American boutique tube-type preamp with a solid-state power-supply. Power-supply not shown. Requires a regulated single-polarity DC supply providing +12V @ 1A. Regulated wall-wart allowed. Example: Triad WSU120-1000-R. DigiKey # 237-1456-ND. $8.45 each. Available at DigiKey. https://www.digikey.com . Rackmount implementation of this project is recommended, with vibration-damping on the mounts. And use pads on the tubes to help mitigate vibrational noise.