What tubes does the Guyatone GA-820 - Normal use?

The Guyatone GA-820 - Normal uses 2× 12AX7 preamp tubes and 2× 6V6 power tubes.

When was the Guyatone GA-820 - Normal produced?

The Guyatone GA-820 - Normal was produced 1960–1968.

Guyatone GA-820 - Normal preset

Close · 68/100 confidence. Most values readable. Minor gaps filled by inference from similar circuits.

Guyatone was one of Japan's earliest and most influential electric guitar and amplifier manufacturers, producing instruments and amps that helped launch Japan's musical instrument industry. The GA-820 was a small tube combo delivering a charming, slightly raw character that appealed to early Japanese rock and jazz players.

Years produced: 1960–1968
Made in: Japan
Channels: 2
Preamp tubes: 2× 12AX7
Power tubes: 2× 6V6

Tags: vintage, 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.