Linn Sondek DIY mods that work

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?
 
Are there any, or should we believe the view an LP12 is like an old violin?


Hi, Just a few words from my experience with Linn, model unknown. Time frame, decades ago, I had just placed my first working sample of a diy Corian TT in operation and was pleased with the results. Of course there was to be further development. Then I found a Linn TT at a second hand swap table and grabbed it based on the brouhaha that Linn was experiencing at the time. Took it home, cleaned it up some and simply could not believe what a poorly designed and built machine it was compared to all the rave notices that were in the press. This is now decades later with the Corian TT still going strong. Other than the prototype Corian TT I had at the time, I had the, now much maligned, Philips GA212 for comparison. Again no contest, GA212 winner in spades.

I'm sure that Linn has come a long way from there judging from their commercial success.

As to comparing an old Linn with an old violin, cigarbox fiddle or rusty roller skate would be more correct IMHO. YMMV!

Best,
BillG

Why not try building your own. You might even be able to salvage the bearing out of the Linn,
BG
 
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As for DIY mods, damping is thought to be the wrong principle for its design, or so it is said.

Damping the steel sub-chassis should be the "first" thing you do. Stock, it rings like a bell, which isn't a good thing IMHO.

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

:confused:

Anyone had any success with table or arm mods?

I put a Jelco 370H on mine. Huge upgrade from the Akito mkI. Also allows cartridge rolling with it's removable headshell.

jeff
 
My very old LP12 was given to me as a box of bits. I'm no TT expert but had to get my head around it to put it back together. I've rewired the Ittok LVII arm, ripped out the basic power supply and connected a DIY Armageddon-esque PSU. I was forced to replace the armboard as mine was warped - I bought a new Perspex one on eBay. The armboard was the bit I couldn't get my head around. Why use a bit of thin MDF to connect a rigid metal sub chassis to a pretty decent metal arm? I don't buy the 'deliberate decoupling' argument - seems like an excuse for an obviously weak link in the chain. Ebay Perspex armboard gets my vote :)
 
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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?

IMO, the responses you've got so far are written by people who have no idea of the construction philosophy of the LP12.

Yes, the pressed-steel subchassis is crap - and requires the armboard to be attached with 3 p*ssy little screws, to provide a lossy connection with the subchassis. The reason for this is to stop the vibrations inherent in the pressed-steel subchassis from 'invading' the armboard. Trouble is, this means there is not a rigid connection between the arm and the platter ... which loses you low-level detail. If you bolt the armboard to the pressed-steel subchassis (to get a rigid connection) ... you get vibrations in the armboard which degrade the sound - but if you then damp the pressed-steel subchassis, you suck the life out of the music.

So you are stuck between a rock and a hard place, with the classic pressed-steel subchassis - which is why the Keel is such a good-sounding upgrade (it now gives LP12s the kind of low-level detail retrieval which other TTs have had for a long time).

The 'Sole' subchassis is one man's attempt to overcome the deficiencies of the classic pressed-steel subchassis and screwed-on armboard. Well before John, there was the Cetech CF-composite subchassis (which came out in about 2000, when the Keel wasn't even a gleam in Ivor's eye! :D ) - I installed one in about 2004 and thought it made a huge difference - although most Linn dealers thought it didn't sound any good. There is a reason for this, though - when you wind up the nuts too tight, the bolt heads stress the top skin of the armboard ... and this stress reaches the arm itself and queers the sound. What you need to do is epoxy some metal collars into the armboard, around the holes drilled for the bolts, so that the bolt heads contact these collars ... and not the top skin of the armboard.

Regards,

Andy
 
If you bolt the armboard to the pressed-steel subchassis (to get a rigid connection) ... you get vibrations in the armboard which degrade the sound - but if you then damp the pressed-steel subchassis, you suck the life out of the music.

I have never understood how removing vibrations that have been added by a vibrating chassis can "suck the life out of the music". This would imply that the vibrating chassis is what contributes "life", as opposed to the vibrations pressed into the vinyl.

What you need to do is epoxy some metal collars into the armboard, around the holes drilled for the bolts, so that the bolt heads contact these collars ... and not the top skin of the armboard.

Wouldn't a washer do the same thing?
 
Wouldn't a washer do the same thing?

Not really - as the washer is still pressed against the top skin of the armboard by the pressure of the bolt head (resulting from winding the nut up tight).

Whereas, if you epoxy a short length of thick-walled ss tubing (slightly shorter than the thickness of the armboard, so it sits slightly shy of the top and bottom surfaces) into the armboard, then the bolt head presses down on this collar... and not directly on the top skin.

I have never understood how removing vibrations that have been added by a vibrating chassis can "suck the life out of the music". This would imply that the vibrating chassis is what contributes "life", as opposed to the vibrations pressed into the vinyl.

Yes, it's an anomalous situation. What you say makes sense - yet there is a long thread on the Linn LP12 Forum about "1001 ways to stuff up an LP12" and many of the posts refer to situations where someone had damped the sub-chassis or the underside of the outer platter.

Andy
 
The really funny part is that there is near-universal approval of damping (and stiffening) the sub-chassis of a Thorens. That's really all I know about, I have never modded a Linn, and I have been told repeatedly that the Linn and the Thorens, though nearly identical to visual inspection, follow different laws of physics. :)
 
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Never an agreed line of thought when it comes to the LP12
I my previous tables have been B&Os and prior to that Japanese.
comparing the construction of a B&O 4000 to the Linn you would indeed see one as a masterpiece of period engineering and the other leaving you scratching your head.
however, despite my respect to the design of the B&O I can see how the complexity could work against it. Some 20yrs back a friend had an LP12 and I know it sounded considerably better than my Sony direct drive of the time.
So, curiosity meant I needed to own one. And further curiosity makes me wonder why upgrades are so expensive and home engineering understood to make these worse not better.
I moved home and passed on my B&O so cannot give a fair comparison between the two.
with some pressings I find the LP12 very impressive, and on others not.
I have an mose external PSU on the way and a project 9cc arm. I hear some praise the cirkus bearing as the must do update but others say keep the original.
I still find it surprising there are no 'winning' diy mods after all these years? Ive removed the base board as this appears the only recommend action.
 
Hi,

I've modded lots of subchassis turntables. Linn's upgrade path
dissuades lot of owners veering off the straight and narrow.

YMMV but a Valhalla is hardly worth "upgrading" to an external
PSU with the the LVX arm fitted, your priorities are very wrong.
Arguably any external supply in an exercise in pointlessness.

Radical mods are exactly that, its no longer original, but
they are possible, it just won't be a LP12 anymore.

rgds, sreten.
 
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I still find it surprising there are no 'winning' diy mods after all these years? Ive removed the base board as this appears the only recommend action.

Hehe - here's my unique 'mod' for an LP12 ... which has definitely improved the sound which I had! :D So I sold my LP12 and Graham 2.2 arm and am a very happy chappie. :)

My 'SkeletaLinn'; it uses the following LP12 parts:
* Cirkus bearing / inner & outer platters
* springs & grommets
* motor & belt.

But no plinth and no top-plate.

The heart of it is a triangular 'chassis' made from aluminium U-channel. This sits on top of the 3 springs and, because the bearing and the arms are bolted to the chassis, it avoids the lossy connection which the standard pressed-steel chassis and armboard has - so delivering better low-level detail retrieval (just as the Keel does).

The motor is off-board - on a heavy, 3" brass 'pod' which acts as a vibration sink. With the 12" 'Univector' UP arm (made here in Melbourne - BTW a 9" one has just been fitted to a 'Keel'), it produced a significant increase in SQ over my LP12/G2.2.


Regards,

Andy
 

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Hi,


YMMV but a Valhalla is hardly worth "upgrading" to an external
PSU with the the LVX arm fitted, your priorities are very wrong.
Arguably any external supply in an exercise in pointlessness.

Radical mods are exactly that, its no longer original, but
they are possible, it just won't be a LP12 anymore.

rgds, sreten.

The Mose PSU will also be added with a new arm , the project 9cc which is the arm Linn now use.

Without the possibility to test every combination of possible updates I cannot claim this is the best path. Opinions vary greatly. The arm has cost me much less than an old ittok would. The PSU gets good feedback but the whole subject is as clear as mud.
 
The Mose PSU will also be added with a new arm , the project 9cc which is the arm Linn now use.

Without the possibility to test every combination of possible updates I cannot claim this is the best path. Opinions vary greatly. The arm has cost me much less than an old ittok would. The PSU gets good feedback but the whole subject is as clear as mud.

El d, the Mose/Hercules PSU is a good-sounding unit. There is also the Falcon/RoadRunner from the US. There is also (but not quite ready for Production status, yet!) the PSU which I am using on my SkeletaLinn (I bought a prototype unit). This is much more sophisticated than the others (and the Lingo!) because you can individually adjust:

* Hz, for platter speed (to 3dp).

* phase (to minimise motor vibration - to 3dp).

* voltage fed to the motor. This is a controversial issue but one which Steve Tuckett, the designer, and I have proven to be desirable (it flies directly in the face of the Lingo philosophy, where motor voltage is initially 110v - to kick start the motor - but then drops to 80v, to achieve minimum motor vibration). The Lingo has to do this because it doesn't have the capability to optimise phase (the optimal phase between the 2 pairs of Premotec motor wires is not exactly 90 deg!); once you can minimise motor vibration, the way is clear to increase motor voltage ... which increases torque ... which makes the music sound better! :D Steve's "Number9" speed controller can also independently control 2 motors ... a feature I am about to take advantage of, with my SkeletaLinn.


Regards,

Andy
 
clearly that was not an afternoons work:D

Haha - indeed El d! :D

I listened to the 12" Univector arm just before Christmas 2012 (mounted on an SME20) - and fell in love with it. So I spent most of my 3-week Christmas break trying to figure out how I could fit one to my LP12. It soon became obvious that I'd have to butcher the LP12, to do this ... which I wasn't prepared to do.

So I started sketching out a triangular chassis, which I decided would be made from bolted-together pieces of aluminium U-channel, 40x25x3mm (knowing that Linn had chosen ally for their Keel!), as this should produce a very stiff, light structure.

I then ordered the LP12 parts from a dealer in the UK and by June 2013 had v1 working - that's when I realised that it was a worthwhile result, so I began the process of breaking up my LP12 and selling the parts, individually.

Now, as with most things, v1 had a minor flaw ... just as with the LP12, one spring was more heavily weighted than the others! :( In the LP12's case, this is the spring nearest the arm; in my case, it was the spring nearest the platter. The solution was obvious - move this spring further away from the bearing ... however, calculating the right distance proved difficult. I eventually got some good advice from the Tweaks/DIY Forum on Audio Asylum (from an engineer who knew his trigonometry! :) ) and when a mate of mine agreed to buy v1 off me, for the cost of the parts, I started to build v2.

This was completed last October - the result (taking into account the weight of the 2 arms I have mounted on the chassis, as well as the weight of the platters & bearing) is that the weight distribution is 36% : 33% : 33%. So almost perfect - and better than what an LP12 achieves. ;) (The heaviest weight is still on the spring nearest the bearing - I should've moved it out another 1/2".)


Regards,

Andy
 
The PSU is an interesting development also. So if you can figure a way to mount a strain gauge to the platter you can adjust your parameters to minimise the vibration. Anyone know of a suitable gauge? In a placeable housing With no inherent damping. Quite how you would wire it to a revolving platter is another question. Often thought of playing with one for stands and the like. But then the question arises are you detecting 'trapped' vibration or useful 'disapating' vibrations.
So is there no ideas to put this TT design into production?
 
Just hold the motor In your hand while trimming phase to feel the lowest vibration setting.

A fully adjustable psu is the trick, then you can thick silicon oil in the bearing, which adds huge amounts of viscous drag to the platter rotation, this forces the motor to drive torque, which compresses the magnetic field, eliminates motor clogging and gives the most remarkable speed stability. But you do need to be able to trim speed exactly to compensate for what would otherwise be slightly slow running.

Here's the link to various pics of mine. It's a 50/50 lp12 Kuzma Stabi S hybrid.

https://flic.kr/s/aHsjz6rmuv