Velleman K4700 Speaker Protection kit installation in Monacor SA230/SW

Dear forum members,

I have successfully assembled and tested Velleman K4700 kit and it is ready for installation in Monacor SA230/SW amp which does not implement any kind of speaker protection or delay itself.

I am planning to proceed with the installation but I have one small issue. I am not sure what type of power supply amp uses symmetrical or asymmetrical and I was not able to find schema anywhere on the internet so I’ve taken multiple pictures of my amp. I am asking this because I don’t know weather I should install resistors R23 - R26. Trafo has three output wires 19V - 0 - 19V so I guess it is symmetrical power supply but I need your confirmation.

I am planning to connect L Mains input after fuse (red rectangle), N mains input on switch (blue rectangle). Desoldier and connect ground of speakers in green rectangle together to ground on K4700, desoldier and connect left speaker (gray rectangle) to PA left speaker and connect right speaker (brown rectangle) to PA right speaker. Connect output LA for left speaker to gray rectangle and LA for right speaker to brown rectangle. Board will be installed in the purple area rectangle. I hope that this is a good plan and that I have not missed anything, please help me with power supply type issue.

Thank you!

Trafo image

Board image

Here is the amp schema