Vinyl Asylum: REVIEW: Mark Kelly Motor Controller Papst 3-Phase Controller Turntables by grinagog

Model:	Papst 3-Phase Controller
Category:	Turntables
Suggested Retail Price:	$ask
Description:	Motor controller with speed control, used on Empire 208
Manufacturer URL:	Mark Kelly Motor Controller
Model Picture:	View

Review by grinagog ( D ) on August 07, 2006 at 21:57:50
IP Address: 202.213.139.125

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for the Papst 3-Phase Controller

I would like to comment on how this works and sounds on my much-modified Empire 208. Mark has done all the development and hard work and his technical description links on the Clarisonus blog here:
http://www.clarisonus.com/blog/?p=92
http://www.clarisonus.com/blog/?p=95
The Mark Kelly Controller solves an issue with my Empire turntable; this uses a 60Hz Papst motor and I live in Tokyo, which has a 50Hz supply
Using a commercially available ( Chubu Systems, CSE ) isolation/regulation device, which kicks the 50Hz input up to a 60Hz signal, the Empire doesn't have enough speed adjustment to compensate for the ( unfortunate ) fact that the platter spins about 2% fast, neither does the CSE have any Hz adjustment to slow the Empire motor down
Calibration: No, that's been done and no improvement
Setup: The Mark Kelly Motor Controller replaces the large Empire start-up capacitor, and a detachable power cable exits the front panel of the Controller into the base of the Empire motor where 3 x cables exit and connect. An external 60W 12VDC 5 Amp switchable power supply plugs into the back of the Unit and connects the Motor Controller to the mains
The 2 connectors do not interchange; it is not possible for a dozy owner to plug the wrong part into the wrong side ( Good! )
Speed adjustment: on the Turntable: The Empire Motor hangs from 3 x rubber grommets and has a knurled nut that adjusts the pitch about 1% fast or slow, by adjusting the angle of the motor against the belt
The adjustment nuts purpose changes with the addition of the Motor Controller to that of a belt tensioner; as the Motor controller over-rides the speed this pitch control would have otherwise governed
This is really "the Business" for dialling in the sound of the turntable
Too much belt tension, the presentation becomes edgy and slightly sybillant, too little and the Bass and soundstage don't focus
Get the Belt tension correct and this steps the performance of the Empire up to a new level. Definitely an improvement!
Speed adjustment proper: the Motor Controller has a small hexagonal lever exiting the right hand front panel, by turning this gently backwards or forwards, provides about plus and minus 8% speed control ( by adjusting the Hz ), confirmed with a KAB speed strobe and KAB Mat used on the platter to gauge actual speed. So dialling in the speed is done using the speed strobe while viewing the KAB mat, and gently adjusting the hexagonal lever on the Motor Controller to dial in a speed that doesn't drift on the KAB gauge
Where the Motor controller shines: I can dial in both the Empires belt tension, by using the knurled nut on top of the motor itself, then dial in the exact platter speed using the hexagonal lever on the Motor controller. I'm surprised how well the Bass and Treble focus when that combination is dialled in correctly, and experimentation to find that right combination is immediate and painless, the motor won't drift once the speed is dialled in with the Motor controller + the KAB strobe used to check that
The Motor controllers operation is simple: once plugged into the mains an LED will light up on the front panel. There is a small toggle switch with 2 positions: Down is "Standby" and powers the Amps and Oscillator, a Yellow LED lights and Mark has advised me that the Motor Controller stabilizes after about 10 minutes switched on. The Up position of the switch is "Motor On", a Blue LED lights in this position, the motor spins
Empire claimed in advertising the platter would get up to speed in 1/3 of a revolution from startup, the Motor controller doesn't compromise that, the speed is achieved almost instantaneously from startup and then speed is held thereafter
If anything, the Motor controller powers up the Empire more effortlessly than "Stock" as the belt doesn't try and move up and down the motor spindle or platter, it just kicks up to speed and stays there
Just How accurately? I don't have an oscilloscope, but I do have the KAB speed strobe which has a 60Hz hand-held LED unit that beams onto a platter mat and shows speed drift as static numbers when the speed is correct and steady. If you have dialled in, say, 33 1/3, and there is no drift detectable on the Kab mat for a minute, KAB claim 99.99% speed accuracy
When I first setup the Motor controller, I dialled in 33 1/3 and ran the turntable for about 12 hours. Rechecking the speed after that initial startup required just a tiny adjustment as the platter was about 1% fast, I attribute this to the controller breaking in, and/or the viscosity of the bearing/spindle oil in the Empire warming up. Using the Motor controller to tweak back to an exact 33 1/3'rd, folowed by a further 48 hours of playing LP's and constant spinning confirmed: NO speed drift and no need for further adjustment, the device is "set it and forget it"
How does it Sound?: by adjusting the tension on the belt at the Empire motor end using the knurled nut, then dialing in the correct speed the best possible combination of belt tension can be dialled in; resulting in a tight Bass and detailed soundstage
Adding the Mark Kelly motor controller has definitely made an improvement in sonics to the Empire turntable. An improvement beyond what I had anticipated
Mark Kelly is based in Australia and has indicated that he may make his Controllers available as a commmercial product, and I urge you to contact him through this forum or his website to followup
Maek was a pleasure to deal with and knows his stuff ad his many helpful postings on Audio forums can attest

Product Weakness: Speed adjustment lever is extremely sensitive and needs only a tiny nudge to go one way or t'other; takes practice + patience
Product Strengths: Promises and delivers Rock solid speed stability; extreme care taken with parts layout and assembly. An honest, quality Product

Associated Equipment for this Review:
Amplifier:	Marantz 8B
Preamplifier (or None if Integrated):	Woodham 300, DACT Phono stage
Sources (CDP/Turntable):	Empire 208, SME V, Ikeda cartridge
Speakers:	12
Cables/Interconnects:	Various
Music Used (Genre/Selections):	Jazz, Rock, Classic
Room Size (LxWxH):	12 x 10 x 8
Room Comments/Treatments:	10 mat Room, nearfield listening!
Time Period/Length of Audition:	48 hours
Type of Audition/Review:	Product Owner

Product Weakness:	Speed adjustment lever is extremely sensitive and needs only a tiny nudge to go one way or t'other; takes practice + patience
Product Strengths:	Promises and delivers Rock solid speed stability; extreme care taken with parts layout and assembly. An honest, quality Product