What tubes does the Bogen Cha 20 Bluesspecial use?

The Bogen Cha 20 Bluesspecial uses 2x 12AX7 preamp tubes and 2x 6V6 power tubes.

When was the Bogen Cha 20 Bluesspecial produced?

The Bogen Cha 20 Bluesspecial was produced 1990s–2000s (conversion era).

Bogen Cha 20 Bluesspecial preset

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

The Bogen CHA-20 Blues Special is a modified version of the standard CHA-20 chassis, revoiced by boutique builders to optimize the amp for blues playing. Typical mods include changed coupling capacitors, a hot-rodded preamp gain stage, and speaker upgrades that push the amp into satisfying breakup at moderate volumes. These conversions became well-regarded among players seeking an affordable vintage blues machine.

Years produced: 1990s–2000s (conversion era)
Made in: USA
Wattage: 20W
Channels: 1
Preamp tubes: 2x 12AX7
Power tubes: 2x 6V6

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.