Linn Sondek DIY mods that work

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#161
Or you could go to a two-belt, 2-motor situation - like in the pic below.

You have to ditch the plinth, though! 😉

My 'SkeletaLinn' has a Karousel bearing plus Tranquility, sits on 3x springs and, obviously, is belt-driven. Originally, I had a Linn Premotec motor driving it but, after finding the 'Number9' speed controller (alas, no longer available), moved to 2x 24v Rega Premotec motors.


SkeletaLinn - with vibration-absorbing motor mounts - inner platter only.jpg
 
#162
thank you for the pic.
"skeletaLinn" - never see before, but looks very interesting. In any case - excellent work.
more URLs:
https://www.stereonet.com/forums/topic/72075-skeletalinn-v2/
https://www.vinylengine.com/turntable_forum/viewtopic.php?t=108583&start=135
https://www.diyaudio.com/community/threads/a-few-mods-to-my-lp12.363847/

pros and cons of two pulley drive against three pulley drive ? for me hard to say.
observe this thread:
https://www.diyaudio.com/community/...3-pulley-drive-system-overview-wanted.390414/
maybe additional replies provide additional information to this question.
 
#167
 
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#168
From the links above, Impexron is perhaps the only source standing a chance to actually supply a 31823 motor. Based on a previous inquiry concerning a different motor i suspect it will be cheaper to buy a new Rega and salvage the motor 🙂 And it's perhaps the only way be certain you are not getting a reject.

Does anyone have experience with the Czech made motors used by Project and Clearaudio?


The Goldnote motor certainly looks interesting. Any ideas about its provenance? Datasheet?
 
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#169
I had a bunch of linn type pulleys machined up a few years for a group buy of meldano's tt psu. They fit project and rega motors. The project motors you can buy direct for the rega motors you have to ask Paul Darwin at rega very nicely for a pulley-less 24v motor, which they will only supply via a rega dealer, or at least they did in the uk for the few guys who needed them.

The rega motors were better, quieter and lower cogging.
 
#170
sq225917 said:
The rega motors were better, quieter and lower cogging.
Click to expand...

Thank you!

The Rega upgrade kit is decently priced and appears to be easily available. Someone perhaps can answer a couple of questions

1. Is the pulley easy to remove?

2. How well does the Rega motor run at 3x the frequency so it can drive a platter directly with the factory pulley?

I have experimented with Thorens sync motors from TD125 mk1 and mk2 and both appear happy in this role but they only required a doubling of the frequency and a slight increase in voltage. The torque at a much higher or lower than the nominal frequency suffers but adding more motors can overcome this.

Changing the pulley, if possible, would be best.
 
#173
analog_sa said:
Thank you!

The Rega upgrade kit is decently priced and appears to be easily available. Someone perhaps can answer a couple of questions

2. How well does the Rega motor run at 3x the frequency so it can drive a platter directly with the factory pulley?
Click to expand...

I use 24v Rega motors on my 'SkeletaLinn', driven by Steve Tuckett's "Number9" motor speed controller. He's no longer with us but I'm sure I remember him telling me that these motors operated fine within a certain speed range (say, +/- 10 or 20%) but did not like being run outside this range.

So I think 3x the specified frequency would not be a good thing.

analog_sa said:
Changing the pulley, if possible, would be best.
Click to expand...

Agreed!
Andy
 
#174
a friend of me want to realize a modification of his turntables - one device is an very old Linn LP12 (from approximately 1978) - second device the model "SOLIST" from Audio Konstruktion.
The internal synchronous motor (which remains on its place) should be replace by an outdoor motor unit.
Before buying anything like new motor and pulley and control unit, in the first step should use the same motor model and pulley in an outdoor motor unit, which I have present from an old AXIS motor control unit - go to
https://www.diyaudio.com/community/threads/repairing-linn-axis-motor-drive-amplifier.103911/page-4

Has done something like this before ?

Conditions that must be observed in any case are the following:

1) Flat belt like
https://www.thakker.eu/riemen/auf-mass/thakker-flachriemen-300-0-x-3-0-x-1-2-umfang-942-mm/a-10555/
is essential (round belts are not helpful in this case due the motor pulley surface).

2) Motor speed must be increase significantly due the changed platter circumference - but this is an easy task by making a new oscillator frequency on the AXIS motor control unit.

Since only a suitable flat belt is necessary in the first step, this is tempting to do.
Who know a delivery source resp. supplier for more oversized flat belts with high compliance ?

Thanks for advices.
 
#178
el donkey said:
Are there any, or should we believe the view an LP12 is like an old violin?

despite reading many threads, views on the commercial products vary widely. As for DIY mods, damping is thought to be the wrong principle for its design, or so it is said.

But in which case there seems little on diy stiffening.

Mine has Valhalla/ Basik LVX.

Replacing the psu with an external one is an obvious path but are there no mechanical DIY projects that work?

Anyone had any success with table or arm mods?
Click to expand...
Hi there,
Linn Sondeks are Linn Sondeks, old or new the plinth and mechanism is mostly the same. there are of course upgrade sub chassis etc but it works the same way. Like an AR or Thorens TD 150.
Purists will hark on about spending their hard earned cash on this and that and look scathingly at DIY jobs as tthey believe that you definitely cannot modify anything. This is passed down from Linn who have money to make. I don't believe anyone only my ears. This is good advice.
I made a 10mm duralloy sub chassis and arm board for mine and I'm working on balancing those components. As for damping the sub chassis, mine rings like Big Ben until the arm board goes on then nothing, The arm board is bolted through with sorbothane between the arm board bolts. I know some people will say this is wrong but I use my ears to distinguish whether it works or not, and it does.
I think the main problem with the Linn sub chassis is balance, one spring does most of the work (nearest the arm) while one just acts like a swivel. I'm a relatively adept mechanic and this doesn't seem correct to me. It means the sub chassis does not go up and down, it moves in an arc swivelling from the single spring. The sub chassis I have in now is my own made Mk 1 (duralloy) this works very well and brings out more detail and depth of soundstage. Hopefully this version Mk2 I'm working on now with deal with the balance issues.
Sound is subjective so it's a good idea to listen to what people say works or not, but it will be subjective and an idea you can use or not. This modification works for me and I like detail and depth of sound stage, I also like my turntable to sound like a turntable and not like a scientific clinic.
I can post a pic if you're interested if I can work out how to do that.
 
#180
This is the Mk 2 that I'm working on now. I've still got to make a balance for the non arm side but as you can see I've left all the solid plate on the single spring end already. I have to get the arm out of my deck to do the balance adjustments and where to place extra weight and have a carbon fibre centrepiece that holds the bearing, The bearing fits on the underside of the carbon fibre disc and that is bolted to the sub platter. I already have that fitted on the other sub platter and it works very well for keeping the platter low enough. It's sitting on top of a standard sub chassis in the picture, I use that as a guide.
 

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