Traynor Bass Master Mk II YBA-1A (1968) - Bright preset

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

This is the first version of Traynor's Bass Master Mark II YBA-1A, built by Yorkville Sound in Toronto in 1968. Two channels with Normal and Bright inputs, treble, bass and low/high range expander controls run through three 12AX7As into a pair of 7027A output tubes with a silicon-rectified, choke-filtered supply; later YBA-1As switched to 6CA7s. Its clean headroom also made it a popular guitar amp.

• Years produced: 1968
• Made in: Canada
• Channels: 2
• Preamp tubes: 3× 12AX7A
• Power tubes: 2× 7027A

Tags: canadian, vintage, bass, two-channel, clean.

Schematic-derived preset files for the Neural DSP Quad Cortex and 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.