• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Pre out on an S5 Electronics K16LS

Hi I need some help adding a pre out for my sub on a S5 Electronics K16LS. Im a bit of a beginner, and build by numbers, but have added a channel selector and some other smaller quality of life improvements on the amp.

I don't know if this is possible, but if it is if someone could help me with where to patch this pre-out signal from off the board.
k-16ls - schematic.jpg