Turntables and power conditioners?

I have an SME 20 here, so I'll take a closer look at how it works. Meanwhile, I will revise my earlier post by saying that it all depends on the turntable you own.

If your particular turntable doesn't have a controller that regenerates power, maybe a power conditioner is in order. Otherwise, I cannot see any benefit.

This is an engineering question. Any recommendation must be qualified pending additional data, as the OP provided insufficient information to support any blanket statement.

Is your local power dirty and/or does it suffer frequent voltage fluctuations? Does your LP-12 lack a regenerating power controller? If so, a conditioner or regenerator may be beneficial.

That dedicated circuit isolates your TT from other circuits in your house. It doesn't isolate it from the neighbors, the shopping mall across town or the crappy equipment at the local sub-station. In fact, dedicated circuits (and Stringreen's high end power cord) connect you even more closely to those problems.

* FWIW, my TT operates on battery power. It's only connected to the grid when I'm recharging the batteries. If I leave the recharging circuit connected when playing music there are audible side effects, even if the recharger itself is powered off. Noise from the grid is pervasive.

Conclusion: the more electrically isolated your TT, the better it should sound. The particulars of how best to achieve that vary with the individual situation.

Dougdeacon nailed it.

I use an AC re-generator dedicated solely to my turntables, which do not have separate controllers, to isolate them from the mains and feed them a constant 115v. I found this approach to sound better than plugging them into a high-end power conditioner or directly into the wall.

Great point Lacee. I'm also with Dougdeacon-isolate and condition.

I use a lenco and hence an AC motor. I have found the only factor impacting sound is the frequency of the power supply.-being a heavy platter idler design impact due to power quality is not much and something i could not really discern
I use a regenerator primarily to keep the frequency stable and that really helps