It's working :)
I've tweaked the
Bipolar Doubler Voltage daughterboard to fit the needs. Just added a couple 12v regulators with two caps to ground (10uf and 100nf ceramic) at the output. This:
What I've done:
1) Input RCAs isolated with shielded cable. Both ends go to the veroboard (input and ground last row).
2) Output RCAs with standard stranded wire. One of them isolated, the other one not.
3) Run a wire from ground row to the isolated RCA output.
4) Join the two RCAs output ground lugs.
5) At the non-isolated RCA output ground lug met the
Bipolar 12v Regulated Voltage ground and the battery ground.
I don't know if there is a better way to do it but it's working fine. I have to finish the enclosure and the box it properly.
Cheers!