Help with Single Supply Preamp into Dual Supply Design

This a guitar preamp schematic taken and modified from a pedal design. I have the idea to put this inside a proper amp head, but the power supply is Dual. How can I convert this into dual power supply? Do I take the all the Vref and make it the 0V and the the ground the V- ?

Thanks for your help


Schematic_VT-BASS_2024-10-29_page-0001.jpg
 
Looks good.
The "OG"...? That first half of the 'Drive'-circuit is somewhat unclear. Just build and modify afterwards if required.
Pin 3 (+) U2.1 on gnd is right.
You might want to replace the 3V3 zeners with an adjustable diamond Vbe multiplier to to enhance this effect.