Altec Lansing 1568A preset

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

The Altec Lansing 1568A is a tube power amplifier built for PA and installed sound. A line input, with an optional plug-in transformer for 150- or 600-ohm lines, feeds one level control and two direct-coupled 6CG7 stages, then a second 6CG7 as a cathode-coupled phase inverter. A fixed-bias push-pull pair of 6CA7/EL34s drives a multi-tap output from 4 ohms to a 70-volt line, with global feedback and a 5U4GB rectifier. No tone controls.

• Made in: USA
• Channels: 1
• Preamp tubes: 2× 6CG7
• Power tubes: 2× 6CA7

Tags: american, vintage, el34, power-amp, 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.