Juergen Simon Advanced Tube Bass Preamp preset

Verified · 86/100 confidence. Complete schematic. All component values readable. Parameters derived directly from the circuit.

The Juergen Simon Advanced Tube Bass Preamp is a 1991 DIY bass preamp with no power stage. An ECC803S input stage with impedance switch and gain control feeds switchable Preshape and Deep inductor filters, then a tube differential stage driving a passive inductor EQ with low-mid, high-mid and treble, plus bass. ECC802S stages and a cathode follower drive the volume, a line out and a transformer-coupled XLR DI, from a regulated 340-volt supply.

• Channels: 1

Tags: diy, bass, preamp, hybrid.

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.