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.


So ask SOTA. The Regen just provides a clean sine wave, not device specific low ripple DC.

You have asked a very complex question, believe it or not. First, one can argue whether "noise" from a turntable motor power supply can even enter the signal pathway. The answer is it can enter by direct radiation of EMI and/or RFI from the PS itself or by retrograde conduction from the SMPS into the power cord into the AC supply which could then contaminate the PSs for your amplification gear, if all the gear shares the same AC source. But in your case, you are protected from the latter phenomenon by the fact that the outlets of your PS Audio power regenerator are isolated from one another. (I trust you do not plug anything else into the outlet that feeds the wall wart.) Distance is the best way to avoid contamination by radiated EMI and RFI, in this case, since it is not practical to add shielding to a wall wart. OK, then the next issue, I think, is that not all SMPS Wall Warts are created equal. Surely some are better engineered than others, and I would feel confident that SOTA used the brains of Bill Carlin, the Phoenix Eng designer, to qualify the existing wall wart. So, let’s assume you have a "good" SMPS wall wart. (The PS Audio regenerator makes it even better because it cleans up the AC going in, in case the filtering of the WW is marginal.) To answer your specific questions, the PS serves the Eclipse/Phoenix Engineering electronics; it does not directly serve the motor per se, and I would guess that if the current setup is giving you stable speed at "33.33" on your Roadrunner, I doubt you would see any change in function with a better LPS; nor would it seem to run "more precisely", whatever you meant by that. I also doubt there would be any change in "motor vibration" on any measurable level. However, the brain is a strange place, so you might "hear" a difference. I have been using an Eagle+RR to drive my Lenco motor, for a few years now. I am completely happy with it, and I am not even sure whether it is running off an SMPS or an LPS. If I wanted an LPS, I would find out what voltage and current output are needed and then build it myself.

Thanks @lewm . My Roadrunner shows me 33.333 + .003 in operation and occasionally shows dead on 33.333 for stretches. I wonder if an LPS would tighten this up any more, if it matters. My measured W/F via Analog Magik is .06, which may in my estimation get even better if I were to upgrade my VPI inverted bearing to a ceramic ball and matching thrust plate.

By more precisely I meant would the motor run at a given speed with less measurable variance.

I do have a question into SOTA so I’ll see what they come back with.

I see much discussion out there about using LPS but nothing concrete about direct TT benefit. I do want to have some details on this as I don’t want to rely on an emotional response of mine.

SMPS technology may he applied to a high end power supply. Iirc CS Port uses them ( although they are run by a retired industrial power supply engineer )...but in general it seems a decent LPS is the easiest way to get into a better quality PS.

Yes better PS make a difference to turntable motor systems. 

A linear power supply is extremely simple.  It uses a transformer, diodes and capacitors and regulators to create a DC output from the incoming AC.

It's the oldest type of such converters and is in most high end audio gear.

A switch mode power supply is more complicated, much higher efficiency, much smaller, lighter and noise can really vary based on design.  Done well it's noise can be equal to or better than the best linear supplies.  Most are not done well. :)

I also have a Condor/Roadrunner. To get it more precise, level the plinth and platter better, and lube the bearing. I usually get 0.04 on Analog Magik or 0.02 on WFGUI by doing so on my VPI.

FWIW, the older Phoenix Eagle/Roadrunner used a LPS similar to the one SOTA has developed. Same case, even. The only difference between the Phoenix LPS and the SOTA LPS is that the latter has connections for both boxes.

Also, when I had the Eagle/Roadrunner, I had to separately ground the LPS. YMMV.

Like I said, it's a matter of individual perception.  Is there likely to be a measurable  advantage to the LPS vs the existing SMPS, in terms of noise in the audio signal or speed control accuracy?  No, I don't think so. But will you hear a difference? Maybe, because of how our brains work.  Brinkmann has for years offered a tube-based motor controller as an optional extra cost item compared to their standard solid state motor controller.  I can't think of a reason for it, but many end users report an improvement with tubes.  (The present situation is not analogous, of course.)

@earthtones , I have a Cosmos with The Phoenix Drive system. It is perfectly normal to see a variance up to +- 0.005 RPM. Mine runs 33.336 +- 0.002. Never in a million years will you hear this. The Phoenix drive also buffers whatever power it is getting. There would have to be a very large variation before it would effect it's performance. I have watched the Road Runner with all sorts of power dipping events and nothing seems to bother it. 

@lewm I was going to mention the Brinkmann tubed power supply. I’ve read that it’s better but I don’t recall anyone giving a good reason why it should be in this application. Now I’m a firm believer in tubes in the amplification chain of my system, but here we’re talking about driving a turntable motor accurately. So, as with the sparse info given on the Brinkmann the last time I checked, I similarly remain unconvinced about LPS benefits in this application. I’m not writing it off and I might just try it..


This is an exercise in frustration for me. A whole lot of words but no mention of specifically WHY and HOW. If I were interviewing someone for a programming job, they would not impress me with this sort of vapid marketing speak:

I am not knowledgeable enough to concoct an explanation for why a tube based motor controller might outperform a solid state one, for performing the function required in the Brinkmann system.  But I do know that such a rationale exists somewhere, if not on the Brinkmann website.  Several years ago, Mark Kelly, a very smart super-hobbyist, developed a tube based motor controller for the Garrard 301 motor.  Mark could give you reasons why he chose tubes for the application rather than solid state devices.  Prior to developing his tube unit, he had already perfected (and sold several) an SS motor controller for the 301.  He built maybe a dozen tube units before going in to business building and selling wood bicycle frames, in Australia.  But it ought to be repeated that none of this has any bearing on the Eclipse system, where the issues are different, and we are only talking about a PS, not a motor controller.

when i had an origin live turntable, the single most noticeable upgrade was to the power.  after replacing the wallwart with a transformer, everything audible improved and til this day is the apex of my musical experience.  and, til this day, i don't understand why a single transformer that powers the tt's motor could alter its sound so much.

Viggen, Sounds like in your case the wall wart WAS a transformer, only. That’s different from the situation under discussion where the wall wart is a complete power supply, meaning a transformer plus the downstream parts required to generate DC at a particular voltage and current.

For the OP, as noted above, all electrical questions in high end are ... complicated.  First perturbation, though, I'm inclined to believe that the elasticity of the drive belt would tend to filter out any micro-differences between a well-designed SMPS & LPS outputs. 

That said, I'm willing to assume that: 1) SOTA carefully chose the wall wart they currently use, and 2) they believed that an LPS *could* make a difference, tried it, and feel that it did.  Maybe they'll let you try one out?

Good luck with your decision!  Please let us know if you take the leap.

@lewm the difference is AC vs DC.  doesn't deny the fact that providing tt motor with cleaner power is a significant upgrade in sound at least IME it was.

I'm sorry.  Where did I "deny" anything?  I simply pointed out that the OP is concerned about replacing a wall wart that contains an entire power supply, which launched a discussion of switching power supplies (SMPS) vs "linear" power supplies (LPS) whereas your wall wart was (apparently based on what you wrote) a transformer.  Whatever else constitutes the power supply of your turntable must reside on the TT chassis; it could be an SMPS type or an LPS type.  Changing the transformer does not change the downstream characteristics of your PS, except whereas many times a "better" transformer may favorably affect function, at least to the ear.


The only experience I have on this is with a Rega and a SBooster LPS. One thing I noticed is when you unplug the wall wart the platter stops spinning. I would think with fluctuations in power the speed could change or alter. I don’t know if you would hear the difference on all systems. 
that being said when you use the SBooster LPS the power is constant because of the power and caps. The green power light stays on for about 30 seconds. The reason why that is important is because it means you have constant power even if the power from the wall gets glitchy. Like a 30 second power buffer. That means you have the same speed all the time. 
I don’t know what the cost of this LPS you are considering. You have to ask yourself could that money be better spent somewhere else like on a cart or phono stage. If you are good on all the rest of the fronts then try the LPS. I hope this helped. 


Welcome back.

Getting ready to open up my last NIB Sharp SD-EX111 for my wife to use in the spare bed/computer room (crossing my fingers that it's still operational after all these years).


dekay old friend! 

you have a very very good memory.  i think we chatted about that amp prrobably more than 10 yrs ago.  time flies.

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.

I am not knowledgeable enough to concoct an explanation for why a tube based motor controller might outperform a solid state one, for performing the function required in the Brinkmann system. 

You need look no further than the NASA Apollo space program.

They bought up most the the Marantz 9 tube power amplifiers when they were launched and used them for power controllers to provide fast power switching.

Similarly I had a friend who built massive mono blocks - 2kw transformers used for the input stages, 5kw transformers used for the output stages. He designed up a rectification circuit using 6550's because the off the shelf rectifiers were melting and could not switch fast enough.


I don't think the NASA story or the friend story are very relevant to either the question of why some llisteners claim to prefer the tube power supply for a Bergmann turntable over the SS alternative or to the question of using an SMPS vs an LPS to drive the Phoenix Engineering power source that in turn drives a turntable motor.  But I also don't claim to know whether or not substituting the SMPS for an LPS would make an audible difference.  Like I have tried to say at least twice, there is no predicting what listener bias can do to one's perception of SQ in that case. I do say that Bill Carlin is a very competent engineer and that I would trust him to design a very good SMPS for his equipment.

I don't think the NASA story or the friend story are very relevant to either the question of why some llisteners claim to prefer the tube power supply for a Bergmann turntable over the SS alternative 

If you cant understand the difference between how tube and solid state rectification behaves then you probably should not be modding your equipment. Their conversion and the way they release of energy into the circuit is completely different.