Universal power for synth gear

I have been playing around with powering all my synths as you would a guitar pedal board by daisy chaining one power supply to all devices. One concern is that standardizing on one voltage would over power some devices and under power others. Also some devices take reverse polarity

For daisy chaining I use a common 5.5mm barrel plug chain cable for guitar pedal boards.

I use a 9v power supply to supply everything. Most 12v synths work fine at 9v (DSI Tetra being one exception in my arsenal). Most devices taking 6v are fine at 9 (Elektron machinedrum has a linear regulator that can get a little warmer than normal but even the folks at Elektron seem to think it’s fine).

For polarity reversal I use little polarity change dongles https://www.amazon.com/gp/product/B071CPLG39

This setup has been working for me really well. I’ll maybe add some more info later.