What tubes does the Ampeg SVT Power Amp (6146B, 1969) - Normal use?

The Ampeg SVT Power Amp (6146B, 1969) - Normal uses 6× 6146B power tubes.

When was the Ampeg SVT Power Amp (6146B, 1969) - Normal produced?

The Ampeg SVT Power Amp (6146B, 1969) - Normal was produced 1969–1971.

Ampeg SVT Power Amp (6146B, 1969) - Normal preset

Verified · 82/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

This schematic specifically documents the 6146B power tube variant of the Ampeg SVT power amplifier section, used in the original 1969–1971 production units. The 6146B is a beam-tetrode tube typically used in RF transmitter applications, selected by Ampeg engineers Bill Hughes and Roger Cox for its ability to deliver high power with exceptional plate dissipation. Six 6146B tubes in push-pull class AB operation produce 300 watts, and the circuit requires a specifically wound output transformer with different impedance characteristics than the later 6550A versions.

Years produced: 1969–1971
Made in: USA
Wattage: 300W
Power tubes: 6× 6146B

Tags: american.

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.