LP12 Radikal problem

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ThomasOK
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Re: LP12 Radikal problem

Post by ThomasOK »

I thought I should mention here that Tony Tune-age posted a writeup about my applying this mod to his LP12 in the Me and My system section. Here ids the link:

http://www.lejonklou.com/forum/viewtopi ... &start=100

I think it does a good job of covering what is done and more importantly the musical benefits he heard. Interestingly his plinth is 65mm but with a Khan top plate. This combination made for a very slight contact of the bottom of the motor with the ring of the Urika foot such that the paper could be pulled out but with a small amount of resistance. I wasn't sure how much difference this would make but Tony found the same kinds of improvements we have heard on other LP12s that have been similarly fixed.

To me it narrows this down a bit by showing that any contact at all is musically harmful and also that 65mm appears to be just below the break point. My guess is that 66mm and above would be fine and 65.5mm might even be OK. It is still important to test any LP12 that is suspect as the depth of the rebate for the bottom and the height of the blocks and strips can vary slightly. Indeed I set up a brand new LP12 with Linn plinth recently where the top plate was just a hair below being flush with the plinth. So a plinth with a 66mm height still might have a problem. The only way to know is to test it.
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Re: LP12 Radikal problem

Post by Charlie1 »

ThomasOK wrote:To me it narrows this down a bit by showing that any contact at all is musically harmful and also that 65mm appears to be just below the break point. My guess is that 66mm and above would be fine and 65.5mm might even be OK. It is still important to test any LP12 that is suspect as the depth of the rebate for the bottom and the height of the blocks and strips can vary slightly. Indeed I set up a brand new LP12 with Linn plinth recently where the top plate was just a hair below being flush with the plinth. So a plinth with a 66mm height still might have a problem. The only way to know is to test it.
My guess is that Linn will very slightly nudge up the plinth depth and maybe reduce any allowable variance below the contracted height, assuming there is one. They can do that without any fan fair. Whereas, if they adjust the motor housing or press out the areas around the Tramp/Urika feet then it's a more obvious change which might put them in a tricky position. This is just guesswork. Of course, my preference is that they tackle this head on and rectify existing Radikal users that are impacted, but perhaps the cost implications for a private company are too much to contemplate. Also, not sure what dealers would think of it. Would they be required to perform rectification works for free? Not sure what the agreement is between Linn and their dealers with something of this nature.
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Re: LP12 Radikal problem

Post by ThomasOK »

A further update. I have worked on two more LP12s with Radikal and Urika or Trampolin 2. On a unit brought back by a customer for a cable change on his Urika and another that I installed the Radikal and Trampolin 2 onto as well as a Kore. Both needed the mod to keep the Radikal motor from pressing on the Tramolin foot. The Urika LP12 with a 65mm tall Woodsong movingui plinth was definitely pressing hard against the foot - I would have ripped the paper if I had pulled it any harder. This is in contrast the Tony Tune-age's LP12 which also had a Woodsong movingui 65mm plinth but where there was only a little pressure and the paper could be pulled out. So another indication of small variances of internal dimensions in plinths with the same height and the need to test. Both these movingui plinths were relatively early Woodsong production before Chris realized that there could be a problem. This latest 65mm plinth table sounded to me like there might not be a problem when tapping the Urika near each of the feet yet it was pressing hard. So you do need to do the paper test to be sure.

The other turntable I installed the Kore, Radikal and Trampolin 2 into was a Linn afromosia plinth with a height of only 64mm. A plinth with the larger corner braces but before the motor stud on the top plate came out. This is the lowest one I have seen yet so it was pretty obvious it would need the mod. Once everything was ready to be fitted with the wood strips in place I put the paper strip in to make sure there was enough added height not to be a problem with the 64mm plinth height. The paper was completely free so no contact of the motor and foot. Since the wood strips I use are about 1.5mm thick (with some slight variance). This further indicates to me that it is likely the break point is about 65.5mm in plinth height. So 66mm high plinths are likely to be OK, 65mm are not and 65.5mm might be OK but I would certainly test it (I would also test 66mm units just to be sure until we have more information).

With the exception of my own LP12 with its 70mm plinth, every Radikal LP12 I have worked on since I first heard about this problem from Fredrik has had a plinth height between 64mm and 65mm, whether made by Linn or Woodsong. Every single one of those has needed the mod for best performance. So obviously this is not a rare occurrence.
Last edited by ThomasOK on 2018-06-19 17:25, edited 1 time in total.
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Re: LP12 Radikal problem

Post by tokenbrit »

ThomasOK wrote: .. obviously this is not a rare occurrence.
Rather, it seems to be a kommon occurence. Glad there's a simple & effective fix...
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Re: LP12 Radikal problem

Post by Tony Tune-age »

ThomasOK,

Have your clients been able to express their opinions and/or thoughts regarding the modification?
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Re: LP12 Radikal problem

Post by ThomasOK »

Another little update on the Radikal and Urika/Trampolin 2 problem. I have had contact from a foreign LP12 owner who was getting some upgrades and was also concerned about this problem. His dealer checked and did find that the motor was in contact with the foot. The dealer suggested attaching the feet to the bottom of the Trampolin so this was tried. The owner was willing to give this a try but was skeptical. He was quite thrilled by the improvements the upgrades made but noticed that the Trampolin feet had much less of their springiness mounted this way. So he took the table apart, put the feet back where they belong and put in the wood strips as we have talked about. He also torqued the new items with settings I had supplied him for them as his dealer doesn't do this. When he got it all together he was pretty bowled over by the additional improvement. Having the Trampolin feet mounted properly definitely provided a lot more music, as you would suspect, and he says he has been listening to a lot of vinyl!

In his note to me he wondered why Linn and some big dealers seem to ignore the Radikal motor/foot problem when, in his words: "an LP12 with a motor that does not hit Trampolin or Urika plays leagues better than the ones that are in contact". I think this also answers the question from Tony Tune-age: my customers who have had the mod have all been quite impressed by the improvement. I think one reason it isn't being dealt with, at least not openly, is that very few people are comfortable going on the Linn forum and talking about what they see as a defect in the product. And there are reasons why some people, not just owners, might want to remain silent. The two threads that were started up there have both gone well into the second page as nobody else is talking about it.

I did have another customer who didn't need the mod but he has a Harban cocobolo plinth with a height of 68mm so it is definitely out of the range where a problem would happen.
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Re: LP12 Radikal problem

Post by Tony Tune-age »

That's another great report ThomasOK, plus it's consistent with all your previous findings as well. And although this particular "design flaw" degrades the sonic performance, it can be relatively easy to correct. Granted, there is an inconvenience factor associated with having a deck checked out and then corrected if needed.

Since this is a real problem that has happened to several decks I really don't understand why Linn can't openly address this issue...especially after several months. It's not as if people are making up a story just to cause trouble. Maybe if the engineers and designers had discovered the flaw first, there wouldn't be so much confusion and mistrust.
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Re: LP12 Radikal problem

Post by sittertal »

Here's another personal experience with the Radikal Motor problem:

About six weeks ago my dealer installed a Radikal/Urika/1. It's a great improvement over the Lingo2/Linto. Although I wasn't completely happy. I thought it needs some run in time. After four weeks it was a bit better but I still had the feeling of driving a car with hand brakes not fully released. After checking many other things like tracking force, torque settings etc. I saw a posting in the naim forum from Peder who referred to this thread. At first I couldn't believe my trusted dealer didn't check this obvious problem. I did the paper Test and there it was: The motor really touched the Trampolin foot. As I don't use the trampolin I just had to remove one rubber foot. Now the TT sounds almost as good as it should. In 2 1/2 months I'll get a replacement for my Kandid which is over 4 years old and well beyond it's way out.

I don't know why Linn says it makes no difference. It's disturbing for me as a Linnie of almost 25 years.

Thank you very much for your great work

Paul
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Re: LP12 Radikal problem

Post by Matteo »

Some rumors say that the Radikal problem is the principal cause of the shut down of the Linn forum ...

I had the Radikal with Trampolin 2 but without the Urika

I did the paper test and found that the motor didn’t touch the foot but the free space between them was very thin ...

I then ordered a solid base without feet ...

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Re: LP12 Radikal problem

Post by Freddy »

Matteo wrote: 2019-01-10 23:12 I then ordered a solid base without feet ...
What kind of feets do you use then? Do think the Solid base II is better than Trampolin II?
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Re: LP12 Radikal problem

Post by Matteo »

With my wall shelf the solid base is more musical

M
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Re: LP12 Radikal problem

Post by Ron The Mon »

Matteo wrote: 2019-02-09 18:55 With my wall shelf the solid base is more musical
Matteo,
To be clear, was your LP12 previously on this same wall shelf? In other words, are you simply saying a solid base (not touching motor at all) sounds better than a Trampolin2 (possibly slightly touching?).

Also, I'm curious how you personally did the paper test. Was it in situ, level, with a record on the felt mat, and dustcover on? Was the tonearm and power cables hanging freely causing more pull? Even though the Trampolin2 aluminum is quite stiff and the suspension feet near the corners, any extra weight on the LP12 (or out of level) will cause more flex. Did you have the felt strips on your Trampolin2 and the solid baseboard as this affects the distance also. Did you have all ten screws in the Trampolin2 and how tight were they?

I mention all this as the distance the motor is from the foot is quite small and there are at least half a dozen variances affecting that and cumulatively could cause touching. Could you also measure your LP12 height?

Also, did you consider Tom O'Keefe's spacer option? I am skeptical of this as every extra millimeter of plinth height also means an extra millimeter of weight around the entire plinth!

I'm considering buying a USB camera to insert into the cavity of my LP12 and document the distance. I originally purchased my Radikal while using a Linn stock cherry plinth, 66mm in height. My original stock Linn Greaves rosewood plinth (64mm in height) was being rebuilt and refinished by Chris Harbin of Woodsong. It took Chris 17 months to complete the job (his queue is legendary). November 2014 I had Tom reset my LP12 with the newly refinished plinth and we were prepared. Both Tom and Chris advised a Trampolin2 foot *screw* would touch the motor and would need to be ground down. I watched and took photos of that rebuild from Tom.

We did a before and after listening test. It was quite apparent the Greaves plinth was much better. When I got home, I was stunned how much better it sounded. Nothing was changed except the plinth and a ground screw. Tom is also extremely anal about LP12 set-up and is very consistent especially with his torque values.

Now I'm wondering if the cherry plinth caused the baseboard foot to touch the motor and the rosewood plinth didn't. Or vice-versa. Or both.

Several months back I received an email from an acquaintance I met on the Linn Forum. He and I had a heated debate years ago as I had some rather negative things to say about how a mostly glue, I mean "bamboo", plinth couldn't sound any good. He was a former Linn employee and knew the makers of the BooPlinth, also former Linn employees. Turns out the guy he sold his old plinth to read of this thread and found the motor touched! It turns out at least one BooPlinth buyer had a problem with his Radikal motor touching a Trampolin2 foot/screw as a result of the stock Linn plinth.

I appreciate Fredrik bringing this problem forward and showing how much more prevalent it is, but a paper test?!? Seriously?

Anyone with a Radikal LP12 has at least $5500 into just the LP playback equipment. I have also paid Tom O'Keefe to torque-spec my LP12 including the 10 Trampolin2 baseboard screws. It boggles my brain cells that I would do a test at home using paper when the distance between a vibrating motor and baseboard foot shouldn't be anywhere near that.

I am hoping to solve this dilemma for less than a hundred dollars and improve the performance of my LP12. If not, my next expenditure is a Keel. Over the past 6 years I have bought every AT95E replacement stylus on the market. All sound worse than the lowly stock AT95E. I am sick of the hi-fi "aftermarket" as I have invested one-third toward a Keel wastefully! I am also more than disappointed Linn still hasn't addressed the Radikal motor touching the Trampolin2 issue.

Anyone recommend or tried a 12-inch flexible USB camera with light to observe this issue?

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Re: LP12 Radikal problem

Post by Matteo »

My plinth is 67 mm.

I did the paper test with the mat and without a vinyl.

The wall shelf is the same.

The (official Linn) dealer is the same.

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Re: LP12 Radikal problem

Post by lejonklou »

Ron The Mon wrote: 2019-02-10 19:23I appreciate Fredrik bringing this problem forward and showing how much more prevalent it is, but a paper test?!? Seriously?
Yes. Seriously.
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Re: LP12 Radikal problem

Post by ThomasOK »

lejonklou wrote: 2019-02-11 11:10
Ron The Mon wrote: 2019-02-10 19:23I appreciate Fredrik bringing this problem forward and showing how much more prevalent it is, but a paper test?!? Seriously?
Yes. Seriously.
Indeed, if there is no resistance on the paper to it being pulled out then there is no contact of the foot with the motor. In my experience, that solves the problem and I have now fixed around a dozen of these. If there is resistance then the spacers should be used or the foot ground down if that is your preference. I have seen a photo or two with a USB camera so that may be helpful, but it may be hard to get it lighted and aimed right to get the true picture. The paper test does it quite simply. As to the wood strips adding weight, there is no question that the balsa strips I use add less weight to the plinth than the difference in weight between plinths of different woods and different heights. After all, how could a 1.5mm thick by 5mm wide perimeter strip of balsa add more weight than what is added by a plinth being 67mm high instead of 64.5mm high?
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Re: LP12 Radikal problem

Post by Ianw »

I followed this thread from the beginning.
I did the paper test as described and found substantial resistance indicating a foul between the Radikal motor base and the Tranp foot. I was very careful to place the paper correctly before closing the Tramp.

Following Thomas guidance I carried out installation of the Balsa strips, again very carefully. Reapplied the paper test and no resistance.

The sonic result was a much more free singing LP12.

I am a Mechanical Engineer and lucky enough to have a Linn jig, so I just took it step by step.
I don’t want to criticise Linn as it is a very fine company in my opinion. Considering the substantial investment required to acquire and run a full house Klimax LP12, I do think this motor to foot contact was just something that escaped the radar on this occasion, it happens to us all and I’m happy to use the spacer workaround.
All just my opinion.
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Re: LP12 Radikal problem

Post by Charlie1 »

Has anyone found that fixing the Radikal motor issue also improves the bass timing? I sometimes notice the bass is slightly out of time compared to my Valhalla deck. I know one member here has always felt the Radikal bass is a millisecond behind the beat, stating that he prefers the Lingo in this respect. It's just that I think my motor is still slightly touching the foot, based upon results of the paper test done last week, so I'm hoping that's the cause. Gonna fit the wooden strips in a few weeks time, just to be sure.

In answer to Ian, I agree people make mistakes. I've made them in my work and will no doubt continue to do so, although hopefully not the same one twice :) My issue is Linn's handling of the problem - i.e. pretending there isn't one.
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Re: LP12 Radikal problem

Post by ThomasOK »

I think the bass timing is one of the major things that the motor touching the Trampolin foot screws up. Bass definition as well. With those two in contact the timing is a bit stilted and sluggish.

I fully agree with your second comment.
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Re: LP12 Radikal problem

Post by lejonklou »

ThomasOK wrote: 2019-02-27 18:43 I think the bass timing is one of the major things that the motor touching the Trampolin foot screws up. Bass definition as well. With those two in contact the timing is a bit stilted and sluggish.

I fully agree with your second comment.
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Re: LP12 Radikal problem

Post by Charlie1 »

Thanks Thomas. Good to know. I will try to make before and after recordings in a few weeks time.
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Re: LP12 Radikal problem

Post by Charlie1 »

Realised I could do this myself by just removing the Urika foot mounting since I don't use the actual Urika feet anymore (went back to traditional feet).

Small resistance during paper test:
https://www.dropbox.com/s/0utz03vhkhgbz ... 2.MOV?dl=0

Urika foot removed:
https://www.dropbox.com/s/hg4adha6zhr7q ... 5.MOV?dl=0

Seems more expressive and timing better to me now. Also makes the 'before' sound mechanical, stiff and overly damped.

I did the second recording after playing just one track - maybe it would have been better to wait for the suspension to settle a bit. Also, the platter had been spinning quite a while prior the first clip, so there's a small advantage there.

EDIT:
Quite pleased with this. Since making recent changes to my main deck, there was one area the old Valhalla/Ittok deck was still superior. It has a lovely natural decay and resonance, very noticable on just a single piano note, for example. I didn't know if it was added by the deck or there on the LP, but it made slower sad or meloncholly music much more emotive. However, since making this change today, the Radikal deck is much better in this respect and now quite close, although still not as good. Everything else is better in the modern deck (tune, dynamics, energy, speed stability, clarity, etc.)
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Re: LP12 Radikal problem

Post by beck »

Once again a very convincing demonstration showing the effect of the radikal/tramp problem.
Playing cd’s…………
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Re: LP12 Radikal problem

Post by Chet »

Clearly better.
LP12 > CD12 > KK1 > Twins >350's Activ
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Re: LP12 Radikal problem

Post by Charlie1 »

Yeah, and to think it couldn't have been pressing very hard. The paper came away with just a bit of resistance.

I had another listen to the clips a moment ago. I'd describe 'before' as nasty compared to 'after'. I know many people think Kans are pretty nasty at the best of times, but even so. The 'before' clip is like there is a stress or pressure applied to the music so that it cannot relax and breath. The more I notice it the more I dislike it.
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Re: LP12 Radikal problem

Post by Spannko »

Yes, the loss of musicality is very apparent. Thanks for the vid charlie1.
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