Power supplies for Linn lp12

[Hiesteem]

I am interested in the various power supplies that can be connected to the lp12.
Particularly how they effect the sound quality, and how they compare in performance compared to Linns own off board power supplies?

The Mober unit is often mentioned, but how does this compare to Linn's off board supplies?
I guess from my own perspective I wonder how a good off board power supply would benefit, if attached to Linn's Majik lp12, buying from new and adding one of these supplies.

 

[2ManyBoxes]

Don't forget the Naim Armageddon. I didn't get the chance to compare I'm afraid, I heard one in one shop and I came across another second-hand in a different shop (bit naughty) at a good price so I went for it.

Be aware that it only has 1 speed though and, as it is apparently just a transformer in a box as against a clever bit of electronics, it is a massive rip off.

How it works I don't know but the LP12 gained enormously in PRaT which went a long way towards justifying the cost

 

[Hiesteem]

Don't forget the Naim Armageddon.

Thanks for your response. Good to hear that your Lp12 improved in sound quality. This is my point of interest really .
The power supply for the LP12 from most reports, nearly always says its an improvement, and in your case in pace, rhythm and timing. Much appreciated.

 

[mega lord]

Avondale Taps is an excellent psu for an LP12 AC motor.

 

[sq225917]

I use the Mober on my kuzma Stabi, which uses a lp12 bearing, subplatter and platter. Sounds great speed stability is rock solid, ni discernable motor noise.

 

[Vinny]

I bought a Pink Linnk from new. The tiny numbers who have used one in comparison to other drives/power supplies generally wax lyrical about the Linnk, but for me, that was FAR too long ago.

Beware some outrageous claims for speed controllers that rely on feedback but are in reality only rev' counters (in other words, a TOTAL joke). If some kind of feedback is used to control speed it needs to be something close to, or better, precisely, continuous.

 

[Hiesteem]

Avondale Taps is an excellent psu for an LP12 AC motor.

Thanks, I know very little about Avondale and so will do some research .

 

[Hiesteem]

I use the Mober on my kuzma Stabi, which uses a lp12 bearing, subplatter and platter. Sounds great speed stability is rock solid, ni discernable motor noise.

I have noticed your not afraid to develop your own table. That is quite a machine you have there. I understand speed pitch and stability is an important factor. Linn seem to advocate this with their lingo 4 and Radikal. Important thing is the mober sounds great! Thanks.

 

[2ManyBoxes]

Thanks for your response. Good to hear that your Lp12 improved in sound quality. This is my point of interest really .
The power supply for the LP12 from most reports, nearly always says its an improvement, and in your case in pace, rhythm and timing. Much appreciated.

I think it's all to do with the drag of the stylus in the record groove. The idea is to maintain the correct speed at all times so that the next note happens at the right time relative to the one that's just produced the drag. The difference between the supplies is how they do that.

How the Armageddon does that, the more I think about it with my feeble knowledge and brain power the less I understand.

I am so glad that in computing it is ultimately zeroes and ones. If you dig far enough for long enough with enough help and resource, there is a definitive answer. The real world is just too complicated. However, we seem to be intent on recreating that situation with the use of so-called Artificial Intelligences

 

[Andrew L Weekes]

I think it's all to do with the drag of the stylus in the record groove. The idea is to maintain the correct speed at all times so that the next note happens at the right time relative to the one that's just produced the drag. The difference between the supplies is how they do that.

There's certainly a speed control element, which is what leads to the crystal controlled mains regenerating style supplies for the original AC synchronous motor. That's not the whole story though, the increasing use of DC motors, which have less inherent speed stability, but lower vibration noise, lower radiated noise and less cogging are clearly becoming the favoured approach, with even Linn taking that route now, athough they're using a brushed rather than brushless motor.

Not sure exactly how their system works, it's monitoring rotation time once per revolution, but the bandwidth of speed corrections must be limited to prevent audible pitch changes?

I modified my own Lingo many years ago to add a fine phase adjustment to between the two motor drive signals, whilst holding the motor you could tune the PSU to match the motor's particular build tolerances, noticeably reducing vibration, an approach I stole from Rega who did something similar on one of their supplies.

This is probably the primary benefit of the Armageddon, just droppping the voltage reduces vibration, and providing torque is sufficient you can get away with it. IIRC the Lingo has a higher start voltage, which then drops once up to speed?

 

[Andrew L Weekes]

Beware some outrageous claims for speed controllers that rely on feedback but are in reality only rev' counters (in other words, a TOTAL joke). If some kind of feedback is used to control speed it needs to be something close to, or better, precisely, continuous.

I'm not sure that's true. The mass of the platter inherently filters high frequency pitch variation, but the potential modulation effect of trying to control speed at high frequency could clearly have negative impacts, you are putting audio-bandwidth corrections (vibration, in effect) into the mechanical interface of the turntable, interfering with your ability to measure the record groove. That was always the criticism of PLL speed controls as present on many Japanese turntables, the PLL bandwidth had audible impacts.

It seems few turntables try to correct for short term load-related speed issues (that's performed by the rotating mass), the primary purpose seems to be absolute pitch accuracy over the longer term.

 

[cpg]

I have obtained a 24V AC motor similar to those used by Rega (identical dimensions to the Linn motor).
A drive pulley to match the LP12 needs to be sourced from a local machine shop and then I will drive my Linn in the future with a Rega neo power supply.

 

[Arkless Electronics]

With supplies that just generate a 50Hz sine wave of low distortion then either they work or they don't.... no reason to think one low THD 240V AC 50Hz sine wave would effect the "sound" of a TT more or less than any other. Anything else would be down to what actual voltage is used, if lower than 240V, to reduce vibration.

 

[Chris]

I use a Norton AirPower after having had a half-width Lingo 1 for over 15 years before that. IMHO the Lingo did not compare at all sounding weedy in comparison with the Norton. Basically it consists of a huge toroidal - I reckon it weighs about 15 kilos in its box - having 2 secondaries outputting 60v and 80v respectively and this ratio is what defines the 33.3rpm speed via the Airpax motor, the belt and the size of the subplatter. No, I don´t know what I´m talking about but I have never felt the need to check the speed or anything. It just works for me. I believe Stereophile once said it was then, back in the "bad" old days of analogue , the best psu for the LP12.
Its designer, Leigh Norton, once published details of a DIY version using 2 much smaller trannies to output the 60v and 80v. It must be on the web somewhere - I believe his page was called "cherryblossom" or something similar.

 

[2ManyBoxes]

@Hiesteem Sorry, I seem to have inadvertently hijacked your thread

The other thing about the Armageddon is that Naim don't make them anymore. If you're thinking about getting one second-hand then you'll need to contact either your Naim dealer or possibly Witch Hat Audio to get it fitted.

When Naim last sold them, £1150 was a bit rich for a big transformer, a resistor and a capacitor in a box you produce a lot of anyway OK the dealer has to fit it but sheesh...

 

[Vinny]

I'm not sure that's true. The mass of the platter inherently filters high frequency pitch variation, but the potential modulation effect of trying to control speed at high frequency could clearly have negative impacts, you are putting audio-bandwidth corrections (vibration, in effect) into the mechanical interface of the turntable, interfering with your ability to measure the record groove. That was always the criticism of PLL speed controls as present on many Japanese turntables, the PLL bandwidth had audible impacts.

It seems few turntables try to correct for short term load-related speed issues (that's performed by the rotating mass), the primary purpose seems to be absolute pitch accuracy over the longer term.

Well, I am sure, even if you are not.
Just take a look at industrial speed controllers where money is no object. You will then realise the nonsense in your post. Also consider mahoosive mass turntables - you are SERIOUSLY suggesting that they change speed due to stylus drag?

Show me some maths with numbers to show otherwise.

 

[Andrew L Weekes]

Well, I am sure, even if you are not.
Just take a look at industrial speed controllers where money is no object. You will then realise the nonsense in your post. Also consider mahoosive mass turntables - you are SERIOUSLY suggesting that they change speed due to stylus drag.

Show me some maths with numbers to show otherwise.

I'm struggling to see the relationship between the two.

You've also clearly made up things you think I said, rather than what I actually said. There's a difference in requirement for industrial speed control vs speed control for a vinyl replay, where induced noise can clearly become detectable at the stylus / record interface, unless care is taken to minimise both amplitude and bandwidth.

And yes, clearly turntable speed is affected by stylus drag, try spinning the platter with no drive or load, then repeat with a stylus tracking the groove and time how long it takes to come to rest. That's the whole reason the motor is there, to overcome frictional loss within the system, at the various contact points.

 

[Hiesteem]

@Hiesteem Sorry, I seem to have inadvertently hijacked your thread

The other thing about the Armageddon is that Naim don't make them anymore. If you're thinking about getting one second-hand then you'll need to contact either your Naim dealer or possibly Witch Hat Audio to get it fitted.

When Naim last sold them, £1150 was a bit rich for a big transformer, a resistor and a capacitor in a box you produce a lot of anyway OK the dealer has to fit it but sheesh...

Not at all 2Many. The information is all coming through and very informative it is too.
This particular subject I find fascinating and after all there are so many options for power supplies. I get the feeling it's an important consideration to extract the best from the Lp12.

 

[sq225917]

The moi of a rotating linn platter and subplatter dwarfes the motor power, the tiny dc motor simply doesnt have power to make sub revolution speed changes and even if it did, the belt acts as a low pass filter.

The feedback loop is there to compensate for thermal drift and it does this slowly, imperceptibly, as it should.

High mass decks dont audibly suffer from stylus drag. Similarly low mass decks with high drag bearings dont either.



I have no idea what vinny thinks crosses over from 500,000 quid machining stations to decks. I bet they cant keep a cutting spindle speed accurate to a few % points either. The 4th and 5th axis positional drives, sure...

 

[2ManyBoxes]

Not at all 2Many. The information is all coming through and very informative it is too.
This particular subject I find fascinating and after all there are so many options for power supplies. I get the feeling it's an important consideration to extract the best from the Lp12.

Well good luck with that From the very quick lookups I've just done, it seems to me that there are 1000s of opinions but very, very little in terms of figures in tables.

Turntables have been around for a long time so they've been constantly refined and tweaked by all sorts of people over that time. Usually those people had a vested interest in keeping the results of their findings to themselves.