Gregory DR-45A preset

Verified · 82/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The DR-45A is a Gregory combo dated January 1966, with a single channel, three inputs, and volume and tone controls. One 12AX7 provides two gain stages; the second 12AX7 serves as the phase inverter and as a phase-shift tremolo oscillator with speed and strength controls and a footswitch jack. A cathode-biased push-pull pair of 6BQ5 (EL84) tubes, with feedback from the speaker, runs on a 6V4 rectifier.

• Wattage: 15W
• Channels: 1
• Preamp tubes: 2× 12AX7
• Power tubes: 2× 6BQ5

Schematic-derived preset files for 16 Fractal and Line 6 modelers: Axe-Fx II/XL/XL+, Axe-Fx III, FM3, FM9, and the full Helix family (Floor, LT, Rack, HX Stomp, HX Stomp XL, Native).

Gridleak extracts amp parameters from original circuit schematics using AI vision — component values, gain staging, tone stack topology, tube types — then generates native preset files for every supported modeler. Every extraction is scored 0–100 and the score is published.