What tubes does the Lectrolab R500 use?

The Lectrolab R500 uses 12AX7 preamp tubes and 6L6 power tubes.

When was the Lectrolab R500 produced?

The Lectrolab R500 was produced 1958–1964.

Lectrolab R500 preset

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

The Lectrolab R500 is a higher-powered model from Rowe International's Chicago factory, pushing toward 25 watts and suitable for more demanding stage and rehearsal applications than the smaller Lectrolab combos. The R500's robust output section and simple but effective preamp circuitry gave it a warm, natural tube character that has attracted vintage enthusiasts and small-studio users. Many examples of the R500 survive under third-party brand names, making definitive attribution a matter of chassis inspection rather than cosmetics.

Years produced: 1958–1964
Made in: US
Wattage: 25W
Channels: 2
Preamp tubes: 12AX7
Power tubes: 6L6

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.