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AirPower Turntable Power Supply
from Leigh Norton
*** Another way to improve your LP12 ***
I have often said in the past that the biggest failing of the LP12 is the motor. You can minimise the damage with a great optimised PSU like the AirPower, but you can improve performance further by using a better motor.
I have done a lot of experiments over the years, and the best sounding motor I have tried on the LP12 is the little Papst unit found in the original Michell Gyrodec/Orbe and Voyd amongst others.
Coupled with an AirPower style power supply (or a Michell electronic unit), the perofrmance of the LP12 is lifted further than you might think. In fact I am surprised Linn's recent upgrades did not include the motor.
Bear in mind you will need to find a way to mount the motor to the left of the deck - a narrow wooden box matching the deck with a metal top plate would be perfect. You will also need to buy or build a power supply.
The motor should be run with a high quality 22uF polypropylene capacitor. Transformers should output around 16v for the directly connected phase and 14v into the phase shift capacitor. Other than that, the standard AirPower circuit can be followed. As always, I would recommend buying variacs and determining the optimum values for your motor as described in the AirPower Kit section.
If you don't fancy building an AirPower, look out for one with a Michell PSU, maybe from someone who has changed to the DC unit. I don't think you'll find much difference in sound quality between the AirPower and QC with this motor (I've tried both with great results but not at the same time so have not made a direct comparison). You don't even need to mod the LP12 - just remove the Linn belt and hook up the Michell one (you have to drive the outer rim of the platter - the same motor running slower and driving the inner platter does not sound as good - I have tried it).
I have one of these motors and a Michell drive belt which I will send it to the first person to send a £25 donation to the excellent Dr Hadwen Trust (sorry, I will only post to the UK).
Even if this one has gone, if you are up to the task and can find one of these motors elsewhere, I urge you to try it - you will be amazed at the difference.
I have a feeling this would beat the new LP12 SE (but please don't hold it against me if I'm wrong - I havn't heard it)!
I have also used this motor with an AirPower on a Thorens TD150 and a TD125 to great effect.
Sorry - the AirPower is now sold
out
click here for details of how to make your own. Sound The Norton AirPower gives a powerful, detailed & rhythmic sound with a huge
soundstage and extended frequency extremes. You will not experience the anaemic presentation of certain other LP12 power
supplies. Linn Lingo Socket Compatibility Comparing power supplies can be a difficult business, setup inconsistencies
being a particular problem. For this reason, the AirPower can be used with the cable fitted to a Lingo
equipped deck. To compare the power supplies, just move the cable between the
Lingo and AirPower - giving a 100% fair comparison. An added advantage of this arrangement is that you can keep your Lingo for
45rpm use when you upgrade to an AirPower.
Design The AirPower uses a custom built transformer tailored to drive the LP12 motor
optimally. Other transformer designs use off-the-shelf transformers which makes
them cheap to produce but compromise performance. As the design is tuned specifically for European mains supplies, the unit is currently only
available for 220-250V 50Hz supplies. The unit is CE marked to indicate that it complies with the requirements of General
Safety, EMC and Low Voltage EC Directives as required by law. History In the mid 1990s I owned two Linn Sondeks - one powered by a Lingo and
the other a Valhalla. I preferred the presentation of the Valhalla but the
improved resolution of the Lingo. I therefore set out to design a power supply
to give what I perceived to be the best of both worlds. The product was originally sold commercially by Norton Technologies Ltd. When
the company wound up, I acquired rights and materials and now sell the product
personally. Price The Airpower can be purchased directly from me for £450 plus shipping costs.
If you are not completely satisfied and return the unit in perfect condition
within a reasonable period, I will refund your £450. The installation process is quite straightforward, but some people prefer not
to get involved in 'the oily bits'. If you wish, ask your dealer to contact me
and I will send them a unit which they can demonstrate and install for you if
you decide to purchase. The price is a little higher at £546.38 including VAT. Contact * Linn, Sondek, LP12 and Lingo are acknowledged trademarks of Linn Products Ltd.
Philips and Airpax also acknowledged trademarks.
