Turntable PSU's.

[alcarmichael]

How can external PSU's from different manufacturers make a turntable sound any different?
Surely if the standard PSU can supply enough power for the motor to drive the platter at a constant speed then that is sufficient?
Or is this the whole point and a standard PSU isn't quite up to the job of maintaining a 100% accurate and constant speed?
Or is it electrical 'noise' introduced by lower specification PSU's which is the problem and fancy PSU's are reducing/eliminating this noise?

[alphaGT]

How can external PSU's from different manufacturers make a turntable sound any different?
Surely if the standard PSU can supply enough power for the motor to drive the platter at a constant speed then that is sufficient?
Or is this the whole point and a standard PSU isn't quite up to the job of maintaining a 100% accurate and constant speed?
Or is it electrical 'noise' introduced by lower specification PSU's which is the problem and fancy PSU's are reducing/eliminating this noise?

Possibly using a bit different current could make the motor run quieter? As to whether it is AC or DC, DC has been said to be quieter, but you've got to change the motor for that. I use a power supply conditioner to supply power to the motor, and it gives me a very stable speed. But it's just the conditioner for the entire stereo, not just for the 'table. So a very stable voltage with a smooth sinewave could theoretically make the motor run smoother and at an exact speed. Vs a supply that is not well filtered or noisy. I know VPI makes an external voltage control for their 'tables, expensive as heck! But it can alter the frequency and change the speed from 33 to 45 without moving the pulley. There's some electrical magic there! People claim to hear great improvements in rhythm and pace, but I'm skeptical.


Sent from my iPad using Tapatalk

[Ali Tait]

I have one of Nick's LDA regenerating power supplies, which is made for decks with mains AC motors like Garrards and Lencos. It makes an obvious improvement.

Guess it could also be used with other decks as long as the rated output isn't exceeded.

[martinjohn308]

I had a Lingo mk 1 on my LP 12 from when they we released but changed to a Naim Armeggedon about 7 years ago or more. With the Naim I found the notes were much much clearer.

Regards,

Martin

[alcarmichael]

I'm not disputing that they don't sound different, personally though I've never done a comparison. I'm just interested to know why they sound different. I can understand mechanical reasoning but electrical engineering is magic!

[cre009]

I'm not disputing that they don't sound different, personally though I've never done a comparison. I'm just interested to know why they sound different. I can understand mechanical reasoning but electrical engineering is magic!

I would not expect that many people are in a position to do a direct comparison. I upgraded my LP12 with a Lingo and my Heybrook TT2 with a TPS based on the word of journalists at a time when I had money to burn and a desire to get the decks to a high a spec as possible.

The problem is that the decks had to be sent to dealers for the upgrade and a direct comparison before and after was not possible for me. These days I might consider doing digital 24 bit ASIO transfers to my PC for comparison purposes but that was not available to me back then.

In both cases when the deck was returned to me I did not perceive any significant change to sound quality. There might have been but I just don't know. The ability to change speed electronically was nice but it was an expensive way to achieve that.

[alcarmichael]

I'm sure there are only very few who have done (as close to as possible) back-to-back comparisons, I read a long thread by REXTON who managed to test several on his deck. I'm more interested in an explanation as to why they may/do sound different. Like I said in the first post, if the original PSU can keep the platter spinning at a constant RPM then why would a high spec PSU make a turntable sound any different?

Obviously the explanation would need to be carried out in such a way that my non electrical brain can understand it. :)

[RothwellAudio]

In both cases when the deck was returned to me I did not perceive any significant change to sound quality. There might have been but I just don't know.

To me, if you did not perceive any significant change to sound quality, there wasn't one - certainly not a significant one.
Some people pride themselves on achieving each tiny incremental change in sound quality and will undertake many A/B comparisons to arrive at them. Some people are more content to leave things as they are if they good. I think I may have migrated from the first camp to the second over the years.

[WESTLOWER]

I have listened to A/B Comparisons of LP12s at Cymbiosis with Peter Swain, believe me there is a difference.
Peter has many different decks set up to test against each other and can offer a very clear demo for non believers.
The Radikal DC motor is far superior to the AC motors resulting in improved sound quality.
As for how or why DC offers a lower noise infiltration to the pick up point I have no idea...

[RothwellAudio]

The Radikal DC motor is far superior to the AC motors resulting in improved sound quality.

I don't think the OP was saying that a change of motor couldn't be heard. I think he was asking how a different power supply for the same motor could make a difference to the sound.

[cre009]

November 1990 copy of Hi Review which had the cover headline "LINN LP12 LINGO THE BIGGEST UPGRADE YOU WILL EVER MAKE".

On page 30 to 35 was the write up by Chris Frankland which contained the following technical content.

"Linn knew that the motor power supply was a vital part of the turntable's performance and that there were many areas where Valhalla was deficient. For a start there was the problem that one was supplying an accurate 50Hz from the crystal but that would beat against the less accurate 50Hz cycle from the mains itself and cause a very low frequency beat signal (0.5Hz say), which was quite measurable. Also using a capacitor to determine phase also meant that it could not react to fluctuations in motor drag and the mains itself. The capacitor also allowed a lot of high frequency rubbish to get through, which was undesirable."

Some discussion about a Valhalla replacement called Wakonda not transcribed.

"The real solution was to house the power supply in its own separate box, allowing the use of a mains transformer to be used for the active circuitry without this intefering with the signals from the cartridge.

Lingo uses two Class A amplifiers, one for each phase of the motor. Both phases are therefore driven actively, which eliminates the variables associated with passive drive and the series capacitor from Valhalla. Thus the motor is more immune to vagaries of the phase shifts caused by mains supply and motor load conditions. For this reason they have been able to dispense with the cup, spring and ball peviously used to put pressure on the motor drive spindle from underneath, as this, they now discover, was obviously helping to isolate it from loading by the suspension, belt drag and so on."

Some discussion about sourcing the crystal oscillator not transcribed.

"Significantly, the Lingo uses much more sophisticated filtering and now they have achieved a situation with both phases accurately driven, where this increased level of performance is completely independent of mains and load fluctuations. Indeed, Lingo has put the mains beat frequency problem down at less than -100 dB in level, whereas before they tell me it could easily be measured with an ordinary multimetre.

A trick they used to good effect in the Axis turntable has been borrowed for the Lingo.With Valhalla the drive voltage to the motor was about 85-95V. For the Axis to give it less motor noise during ordinary load conditions they built a circuit which applied a high voltage, 85V, to give it the necessary torque at start up, but once the motor was locked to speed, would drop the voltage to 65V. This meant that motor noise was a lot lower."