Harmony H-204 - Microphone preset

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

The Harmony H-204 is a mid-1950s combo with a Mic input and two Instrument inputs, each side with its own volume and a shared tone control. Low-gain 12AY7 stages with small input coupling caps feed a paraphase inverter, also a 12AY7, and a push-pull pair of 6V6GTs on a 5Y3GT rectifier into a single 12-inch speaker. It makes about 8 watts, with a lean, clean voice that turns gritty at full volume.

• Made in: USA
• Wattage: 8W
• Channels: 2
• Preamp tubes: 2× 12AY7
• Power tubes: 2× 6V6GT

Tags: american, vintage, 6v6, low-wattage, clean, 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.