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Lenco and Garrard external ac power supply

Been thinking about this recently...Does it even make sense to try to find someone willing to build a power supply for turntables such as the Lenco L75 or Garrard 301 when they were made to just be plugged directly into the wall ac in the first place??

Loricroft makes ones for the 301 that convert ac to dc then back to "perfect" ac again which is what something like a Pure Power ac line conditioner/regenerator does. The neat thing about the Loricroft is that you can apparently adjust the 301's speed with it. It would be trick to find something like that for a Lenco 75 that was not so expensive.

PS audio used to make some big line re-conditioners that did the same sort of thing I think back in the day but I don't know if they are making the same equipmnet still. Furman and a couple others I think do similar things also.

What would be neat would be to find a ac regenerator that you could use to control the speed of either a 301, 401 or Lenco 75. Since they are all AC and can run at 110 or 220 volts maybe its possible, I don;t know but I know the Loricroft controller is way way expensive is it really worth $4000 bucks?? Thats almost as much as a restored 301 or top Lenco....geesh

Maybe you could just save the 4000 bucks and build one??/ Could it really be that tough?..
jeremy72
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xactaudio
156 posts
 
Correct Jeremy, the speed of the 301 motor is, in large part, determined by the frequency of the mains. The voltage controls the torque and will affect the speed to a much smaller degree. The 301 will operate at correct speed with 47Hz and around 230v with some of the 50Hz pulleys and minimal eddy current brake. Remember, Garrard made many variations (by design and machining tolerances I am guessing) of pulley diameters for 50Hz because post war Europe had a fairly large variation in voltages. To get the most out of the 47Hz setting, a custom pulley needs to be used so the eddy current brake can be used to maximum benefit and optimal voltage (torque) dialed in.
I have not tested the Lenco motor but no doubt it will have a different preference. Most likely very different.
lewm
13,002 posts
 
Steve, Armed with the knowledge that you just dispensed, would it not then be possible to control an induction motor (i.e., my Lenco) with a power re-generator like those made by PS Audio, assuming that one or more of their products do allow for control of AC frequency? (I don't remember for sure whether that is true.)
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xactaudio
156 posts
 
Lew, to a degree yes, you could control the Lenco. I do have at least two customers that have tried using newer PS Audio units on their Garrards and were less than excited by the results. I do not know much about the newer PS units but I lived with a P300/PS300 7-8 years ago. It would go down to 50Hz but only in 5Hz increments and the voltage would only go to about 135. And even though PS Audio claim it to be balanced, the voltage varied by 20-30% from side to side. Anyway, the range is severely limited for what you would need to control a Lenco or Garrard. I doubt you would generate enough voltage to compensate for the lower Hz in a Lenco and for sure not in a Garrard. The limited Hz choices of 50 or 55hz would probably be less than optimal. If you are serious, you need to get a Loricraft 301 control unit or one of the scientific power supplies floating around.
theedge's avatar
theedge
7 posts
 
Have you checked at LencoHeaven, because someone there was / is designing a motor controller.
lewm
13,002 posts
 
I noticed that. Still on the drawing board, I think. Thanks to Vetterone, I can conceive of building one from a frequency generator (saw a very cheap solid state module on eBay with a built-in digital read-out) driving an amplifier that can push ca 120V into whatever is the load of the Lenco motor. (I would need to measure that.) Might be fun to try that.
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