RO SpaceGroove Guitar Preamp PUBLIC

RO "SpaceGroove" Guitar Preamp with Real Tube Fuzz.

Richter Original "SpaceGroove" guitar preamp with real tube fuzz and 3-band tone. Controls Include: Gain, Drive, Bias, Bass, Mid, Treble, Bright switch, Mid Boost switch, Deep switch, Stack Sum, Attenuation, and Volume. Fuzz comes from overdriving the tube with sufficient Gain and Drive settings. Frequency Range 8 Hz to 18 kHz with all controls at 50%, or 4 Hz to >20 kHz with all controls at 100%. Maximum Gain = +19 dBV @ 400 Hz with all controls at 50%, or +25 dBV @ 1 kHz with all but Tone controls at 100%. Note: Tone controls have subtle effects but Attenuation control has significant effect when set < 50%. Project is suitable for 6/7/8-string guitar or 4/5/6-string bass. Power-supply not shown. Requires +12V DC @ >= 550 mA, filtered unregulated or unfiltered if regulated. Schematic verified valid by CircuitLab's Frequency Domain Simulation using a MOSFET subcircuit configured to simulate the 12K5 tube's subcircuit. [See: RO SpaceMOS Guitar Preamp.] Note: The 12K5 is a space-charge tube designed to be operated from a +12V DC supply-voltage on heater AND plate. It was chosen due to having a reputation for being the 12V space-charge tube that sounds more like one triode from a 12AX7 twin triode preamp tube than any other space-charge tube. However, though simulator verified, the circuit should be considered experimental. Breadboard test before committing to a soldered build. And house in a grounded metal enclosure.