Linear Power Supply?


Can someone tell me exactly what an LPS supposedly does to improve the operation of a turntable motor? Does it run more precisely at a given speed? Does it vibrate less? I have a SOTA Eclipse motor with Condor and Roadrunner. SOTA is coming out with an LPS option which they say is better than the SMPS wall wart, but I want to know exactly how it’s better. If less noise in my system is the benefit, then I believe I already have that addressed because I plug it into my PS Audio P20 power regenerator.

earthtones

The LPS perhaps keeps the platter spinning a bit longer because its capacitors hold charge for several seconds after unplugging the unit. Until the DC voltage falls below a certain threshold, the platter will keep spinning. No magic.

Linear Tube Audio sells a separate LPS for around $600 to replace wall warts in electronics so I bought one for my turntable. I think it improved the sound a lot but not entirely sure as these things go…but I like the tweak and it makes me feel good.

 

Rega tables have optional PSUs fairly down their product line and they are standard on their top 3 models I believe. The PSUs plug into a wall wart.  A rudimentary speed measurement (with an iPhone on the platter) showed RPMs of 33.28 and 44.98 (.15% and .044%). I suspect with that weight removed it would speed up a tiny bit, but I would challenge anyone to detect the difference.

I put a LPS into my phono stage and it probably made a difference statistically, but I couldn't hear it, but it wasn't an A-B comparison. That would be really tough to do. The manufacturer told me if it was his brother in law, he would tell him to do it. He didn't mention if he liked his brother in law :-)

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So I purchased a SOTA LPS recently and I've been using it for a couple of weeks. The sound quality certainly isn't worse than before and it may well be better. It measures marginally better through Analog Magik. When I last measured Wow/Flutter in late 2021, I was getting .066 and now I'm getting .064. I doubt that I can hear a difference based on this alone. Also, I'm using the same belt as before, which may have stretched slightly - a good thing in this case, and the bearing temperature may have been different. I did let the turntable play about 10 minutes before testing. Also of interest is the possible reduction of switch mode power supply noise fed back into my system - even through a PS20, which I suspect may not completely eliminate such noise. On a side note, I have also eliminated all switch mode power supplies except for those on the ethernet side, which is isolated optically. So, maybe the SOTA LPS is better, maybe it doesn't make a difference. It's hard to know because of all the variability in the system. But based on what I've mentioned, I am glad I purchased it.