Ampeg Rhapsody 435S / Zephyr 635S - Channel 2 preset

Verified · 88/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The Ampeg Rhapsody 435S and Zephyr 635S are 1960 accordion and instrument combos sharing one circuit. Two channels, plus a stereo input, each have 6CG7 stages with their own Bass, Treble and Volume, mixed into further 6CG7 stages. Ampeg's vibrato uses a 12AX7 oscillator with speed controls and footswitch driving a matched-diode ring modulator; an EF86 stage and 6SL7 paraphase inverter then feed two cathode-biased EL37s.

• Made in: USA
• Wattage: 35W
• Channels: 2
• Preamp tubes: 4× 6CG7, 1× 12AX7, 1× EF86, 1× 6SL7
• Power tubes: 2× EL37

Tags: american, vintage, 6l6, mid-wattage, 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.