Turntable Power Cord Upgrade

The same applies AC or DC. The main exception being if the DC involves a battery, and if the AC charging the battery is disconnected during play. Because essentially, as I just showed, as long as there is any connection to AC then some of the noise on the AC line is going to get to the DC. The one exception is when a battery is used, and even then only when the battery charger is disconnected from the line during play.  

This isn't guesswork or rumor. This is actual experience running all these different ways.

Why not put the power cord (minus the ends) inside the chassis between the power supply capacitors and the circuit boards? That should improve the "imperfect" power supply according to millercarbon's logic!

Changed out the wall wart for a linear power supply the speed is perfect 

+1

Got rid of the wall wart and bought a linear power supply for my previous TT. And I did upgrade the power cord for it, albeit with a modest one.

Funny enough, I never bothered to A/B them. Perhaps I didn't want to know if I had wasted money...

However, it would seem reasonable to think that a more stable power supply would at a minimum provide better consistency with motor speed. And, when I sold it, it went with the manufacturers wall wart, which means I now have a very clean 12V power supply to play with:)

About to finish a heavy plinth Lenco L70 and will be using "better" wires throughout once the build is completed and its running properly.

Every little bit matters, and a big thing is just a whole lot of little things put together.