The necessity for absolute tt speed control

[edwyun]

And what was speed accuracy before Condor?

Always had an eagle or condor with the VPI so I never tested the original VPI/Hurst motor for speed stability. I still have the VPI/Hurst motor, and just testeed it. Mind you, it has been sitting for several months...

 

[edwyun]

Interesting. Can you show the wow and flutter measurements in log scale? They are meaningless in linear scale.

Would if I could. The AnalogMagik software doesn't allow me to. Perhaps you should as Richard Mak?

 

[edwyun]

Edwuyn, does Condor/Eclipse bring anything other than straight speed to proceedings? I mean, less noise/vibrations, advantages re torque?

In my case yes...

http://www.vpiforum.com/viewtopic.php?f=7&t=14369

 

[microstrip]

Would if I could. The AnalogMagik software doesn't allow me to. Perhaps you should as Richard Mak?

A pity it is not possible, it would partially answer to Mike question. If you are interested try Spectraplus at www.spectraplus.com - it is free for 30 days.

 

[spiritofmusic]

I'm starting to get it. RR is giving me way closer awareness of speed, drift, and my ability to set as accurately as my motor will allow things. I'm starting to be more aware of the things that more accuracy here is providing. Primarily atm, piano reproduction, and the ability to differentiate individual instrumental lines in massed passages. This is so gonna open up classical music enjoyment.

 

[microstrip]

I'm starting to get it. RR is giving me way closer awareness of speed, drift, and my ability to set as accurately as my motor will allow things. I'm starting to be more aware of the things that more accuracy here is providing. Primarily atm, piano reproduction, and the ability to differentiate individual instrumental lines in massed passages. This is so gonna open up classical music enjoyment.

Are you addressing accuracy or precision?

 

[edwyun]

Are you addressing accuracy or precision?

IMHO, the RR will give you the ability to know whether your speed is accurate (or not) so you can adjust as needed. The Condor will give you the ability to have precise speed stability given is AC regeneration. Either or both separately may be all that you need. But by connecting both and using the feedback loop, you get both high accuracy and high precision.

 

[Lagonda]

I'm starting to get it. RR is giving me way closer awareness of speed, drift, and my ability to set as accurately as my motor will allow things. I'm starting to be more aware of the things that more accuracy here is providing. Primarily atm, piano reproduction, and the ability to differentiate individual instrumental lines in massed passages. This is so gonna open up classical music enjoyment.

Marc, did you check how much your original setting was off before you started adjusting speed according to Roadrunner readings ? If you are hearing an improvement it must have been off a lot. You know my personal experience have been that the torque and smooth power delivery is much more important than absolute precision. I have gone trough 4 different motor setups recently, and the one with the least stable speed is clearly the best sounding motor by a large margin, and the most speed stable one is the worst sounding ( and all is relative here). That being said, the “unstable” motor still maintains 33,3 rpm, but not 33,333 like the small motor does.

 

[spiritofmusic]

Milan, some agreement between strobe and RR at start of playing an album. But within a minute I'm adjusting the RR, and for a few mins more. It's this period that inequalities are apparent, and I can finally adjust on the fly.

Gonna go 90 mins warm up running motor today, and see how steady things are on playing the first LP.

 

[spiritofmusic]

Well, nearly 6 months on from posting this thread in genuine curiosity mixed with some skepticism, I can really report this stuff is critical.

On my old stock motor, where there didn't "appear" to be any major SQ variation at 33.000 v 33.333 v 33.666, I took a lot of convincing to go down the route of guaranteeing 33.331-33.335, often 33.333. My perception at +/- 0.3% error was of no real difference to ideal, so why spend £1.5k guaranteeing +/-0.03%?

If "hearing is believing" before, then the audible uptick with new motor is more "hearing is convincing". It took a day for the motor to run in and show it's stuff, and the change is radical and deeply addictive.

I'm gonna agree with Lagonda here, it's not the absolute numerical speed accuracy that's most critical, it's the lack of moment to moment waver. So where my old motor would literally wow in and out like waves on an ocean, swirling and receding second to second, sometimes from 33.100 to 33.600 and back in the space of two revolutions, the SOTA Eclipse motor I'm now using is 99% of the time at 33.332 to 33.334, only very occasionally varying lower or higher.

This lack of cyclical swings and roundabouts is making the critical difference. And WHAT a difference! I know I'm prone to that awful audiophile malady Epiphanous Pretentiousity, but the change here is of an order of magnitude greater than any other changes, save for my room acoustics uplift (actual room move and major bass suckout solution), and isolation of tt via Stacore/correct analog setup. I would say by having these factors sorted, the uplift from minimal speed drift with the new motor is magnified.

Where I'm so happy is the dramatic turnaround on classical. The Janacek/Mládi piece I listened to the other day is transformed from a tad grey and smeared to uncluttered, hugely transparent, dynamics especially improved, timbral accuracy and air to spare. For the first time, classical music that always felt shut in and gritty via my Zus, is sounding much more independent of the spkrs, way closer to the great systems I've heard in the last few years.

I think it's the combination of the joy of a situation I was having a hard time being convinced could result, nailing once and for all that Zus can be hugely transparent, and literally opening up hundreds of my classical and jazz albums to new appreciation, that has made this stage of my system evolution the most joyous one.

I can only thank my good friend running the same tt/arm who kept me in the loop on this change as I remained hugely skeptical.

 

[robyatt]

Trouble with rim drive is speed stability . The physics of two rotating surfaces turning in different directions and in contact with each other is they are trying to drive each other away. A traditional idler under the platter is turning the same direction as the platter- far greater speed control and stability.

 

[spiritofmusic]

That's a fascinating take. I wonder if a Kronos-style dual counter-rotating platter system would work. The platter being driven having the "issues", the other one easing these issues. Interesting thought experiment.
Maybe this explains why the SOTA motor never gets closer to 33.333 over any protracted period than +/- 0.003.
Whatever, the SOTA install has led to the single biggest improvement in LP enjoyment, across the board...albums, genres, day to day listening.
Has literally opened up classical and jazz, nails my prog/fusion genre faves, opened up new perspectives on LPs that I'd given up on.
Only a small number of brickwalled albums from mid 90s onwards struggle to reveal their inner charms, and leave me conflicted...Living Colour/Vivid, Rush/Clockwork Angels are prime examples of vandalised production/mastering decisions cruelly revealed by the SOTA upgrade.

 

[Vienna]

That's a fascinating take. I wonder if a Kronos-style dual counter-rotating platter system would work. The platter being driven having the "issues", the other one easing these issues. Interesting thought experiment.
Maybe this explains why the SOTA motor never gets closer to 33.333 over any protracted period than +/- 0.003.
Whatever, the SOTA install has led to the single biggest improvement in LP enjoyment, across the board...albums, genres, day to day listening.
Has literally opened up classical and jazz, nails my prog/fusion genre faves, opened up new perspectives on LPs that I'd given up on.
Only a small number of brickwalled albums from mid 90s onwards struggle to reveal their inner charms, and leave me conflicted...Living Colour/Vivid, Rush/Clockwork Angels are prime examples of vandalised production/mastering decisions cruelly revealed by the SOTA upgrade.

Marc months ago I was interested on Kronos tts and had high expectations.
having measured three different Kronos Pro in different systems I saw wow/flutter values over 0.24% and very unstable speed.
Perhaps their new Enterprise model will measure better, the photos I saw look promising although the same motors are used.

Discussing the speed stability issue with Bill Carlin (in my opinion the best at this field, and the designer of your speed controller) he had explained me, how challenging is to control two motors .

 

[Mike Lavigne]

Trouble with rim drive is speed stability . The physics of two rotating surfaces turning in different directions and in contact with each other is they are trying to drive each other away. A traditional idler under the platter is turning the same direction as the platter- far greater speed control and stability.

hi Robin,

welcome to What's Best Forum. good to see you here.

i sure enjoy my Saskia idler. love it's speed, drive and low noise.

cheers,

Mike

 

[spiritofmusic]

Marc months ago I was interested on Kronos tts and had high expectations.
having measured three different Kronos Pro in different systems I saw wow/flutter values over 0.24% and very unstable speed.
Perhaps their new Enterprise model will measure better, the photos I saw look promising although the same motors are used.

Discussing the speed stability issue with Bill Carlin (in my opinion the best at this field, and the designer of your speed controller) he had explained me, how challenging is to control two motors .

If its gonna be called The Enterprise, let's hope it's driven slightly better than Counselor Deana Troi driving the REAL Enterprise in Star Trek: Generations lol.

 

[Vienna]

If its gonna be called The Enterprise, let's hope it's driven slightly better than Counselor Deana Troi driving the REAL Enterprise in Star Trek: Generations lol.

The speed display is contained in a spooky round glass bullet with metal conical edges

 

[spiritofmusic]

Marc months ago I was interested on Kronos tts and had high expectations.
having measured three different Kronos Pro in different systems I saw wow/flutter values over 0.24% and very unstable speed.
Perhaps their new Enterprise model will measure better, the photos I saw look promising although the same motors are used.

Discussing the speed stability issue with Bill Carlin (in my opinion the best at this field, and the designer of your speed controller) he had explained me, how challenging is to control two motors .

I don't understand this. I thought the WHOLE Kronos dual counter-rotating platters schtick was, in addition to other areas, to ensure better speed stability.

 

[Vienna]

probably the design is introducing a rocking couple, with two completely independent platters so far apart , bearings and two motors.

Perhaps this concept to work as intended, would need the lower platter to play the same record as the upper platter at the same time with the same bearing and both motors perfectly synchronized

 

[spiritofmusic]

Trouble with rim drive is speed stability . The physics of two rotating surfaces turning in different directions and in contact with each other is they are trying to drive each other away. A traditional idler under the platter is turning the same direction as the platter- far greater speed control and stability.

Rob, obviously what you're saying makes a lot of sense, its undeniable...the rim wheel pushes one way, the platter is driven the opposite way.
Its like the Bumblebee...look at one closely, it should never get off the ground Lol.
It was educational to see quite how challenged my stock motor was when the Roadrunner speed tach was initially installed, 0.3% plus or minus, never consistent.
Maybe this opposing couples phenomenon specific to rim drive was always gonna overwhelm a cheaper stock motor with no speed oversight/correction.
And maybe that's why the SOTA motor install has been so radically positive, its literally wrought a challenge into a solution. And that solution, if not the absolute accuracy seen on GP Monaco or even AS200 or SME, is achieved by eliminating a lot of speed waver moment to moment.
For me, other than the occasional brickwalled album from the last couple of decades, my collection has been only helped by this move, many LPs dramatically effectively extending to most records in whole genres.
The SOTA motor/Farad LPS has been like a Swiss Army Knife fix for my whole analog, which has a result enabled me to more clearly rule out what I thought were issues downstream linked to the amps and spkrs.

 

[thedudeabides]

Has anyone determined the deviation from the ideal speed (from a percentage measurement) where that error is audible?