Harmony H-306A - Channel 1 preset

Verified · 90/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The H-306A is a revision of the H-306 tremolo combo: four inputs feed two channels, each with its own volume and tone control. One 7025/12AX7 is the preamp, a second is amplifier and phase inverter, and a 6SH7 oscillator runs the tremolo with speed and modulation controls and a footswitch jack. Two 6V6GTs on a 5Y3GT rectifier drive a 12-inch speaker: warm and clean at moderate volume, grainy when pushed.

• Made in: USA
• Wattage: 12W
• Channels: 2
• Preamp tubes: 2× 12AX7, 1× 6SH7
• Power tubes: 2× 6V6GT

Tags: american, vintage, 6v6, tremolo, low-wattage, breakup, two-channel.

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.