Harman Kardon A300 Tube Amp preset

Verified · 92/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The Harman Kardon A300 is a stereo valve integrated hi-fi amplifier with identical left and right sides. Each side has a 12AX7 phono preamp with RIAA equalization, a selector for phono, tuner and aux inputs, and a 12AX7 tone stage with loudness, bass, treble, balance and filter controls. Half a 12AX7 drives half a 12AU7 split-load inverter into a cathode-biased push-pull pair of 7408 (6V6-type) tubes with feedback, on a silicon voltage doubler.

• Made in: USA
• Channels: 1
• Preamp tubes: 4× 12AX7, 1× 12AU7
• Power tubes: 4× 7408

Tags: american, vintage, stereo, 6v6, clean.

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.