LP12 Bounce

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Defender
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Re: LP12 Bounce

Post by Defender »

is it true that one way of testing a good setup with respect to bounce of the LP12 is to set the needle on the record without letting the turntable spin and while making the bounce test check if your bass drivers are not moving/pumping ... or is that not achievable
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Re: LP12 Bounce

Post by Charlie1 »

Never heard that before. Most people test it whilst the deck is idle and arm on the armrest as far as I can tell. You need to know where the centre of gravity is though. Or you can test it whilst the record is playing. I tend to use the end of my finger nail because my finger tip can sometimes grip on the record surface causing it to judder. Best to keep tapping it gently and slowly build up a bounce...

https://www.dropbox.com/s/tg98hbti3gigv ... 9.mp4?dl=0
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Re: LP12 Bounce

Post by ThomasOK »

I have not heard of that one either. I'm not sure how accurate that is as the dynamics of the suspension are likely to be slightly different when the platter is not being powered by the motor/belt. My final test for the suspension is indeed to lightly bounce the suspension at the center of gravity whist playing a record. If the stylus doesn't stay in the groove then the suspension gets readjusted until it does. Higher compliance cartridges like the Adikt respond worse to side motions than cartridges like the Krystal and Kandid so the suspension needs to be just right. If the cartridge stays in the groove, shows no side to side motion of the body, and plays without noticeable modulation of the music with a small amount of bounce to the sub chassis then you have a very good suspension setup. I do generally show my customers this when they pick up the LP12, but I add the disclaimer: "I am a trained professional. Don't try this at home!" ;-)
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Re: LP12 Bounce

Post by Defender »

its mentioned in this review http://soundvision-fi.de/cms/downloads ... LP12SE.pdf
unfortunately only in german language. It said the Linn guy did set the LP12 up controlled the bounce with placing the arm/cartridge onto the non spinning record and checked the bounce - the bass drivers moved so he was not happy and corrected the bounce and afterwards when doing the bounce test the bass drivers didnt move anymore.
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Re: LP12 Bounce

Post by Tendaberry »

Defender wrote: 2021-06-23 17:00 its mentioned in this review http://soundvision-fi.de/cms/downloads ... LP12SE.pdf
unfortunately only in german language. It said the Linn guy did set the LP12 up controlled the bounce with placing the arm/cartridge onto the non spinning record and checked the bounce - the bass drivers moved so he was not happy and corrected the bounce and afterwards when doing the bounce test the bass drivers didnt move anymore.
Ironically the Linn Account Manager setting up the LP12 in the test is called Mr. Wabbel (German for wobble...)
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Re: LP12 Bounce

Post by Spannko »

That’s a new one on me too, but let’s not reject it without trying it. It certainly makes sense, as does TOK’s method. What about playing a silent track and checking the bounce?

I’ve always thought that the most important part of the bounce is “the last ounce of the bounce” - the micro bounce as the bounce dies away. Is it still pistonic and free or does it tense up and begin to wobble like a jelly on a plate? The bass unit movement would likely give an indication.
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Re: LP12 Bounce

Post by Charlie1 »

Defender wrote: 2021-06-23 17:00 its mentioned in this review http://soundvision-fi.de/cms/downloads ... LP12SE.pdf
unfortunately only in german language. It said the Linn guy did set the LP12 up controlled the bounce with placing the arm/cartridge onto the non spinning record and checked the bounce - the bass drivers moved so he was not happy and corrected the bounce and afterwards when doing the bounce test the bass drivers didnt move anymore.
I had a play. My Sara woofer only moves if the stylus skips - i.e. If I'm not bouncing the record in the right place or being too rough with it. So I think this is pretty much the same test as bouncing an LP whilst playing.
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Re: LP12 Bounce

Post by Charlie1 »

Spannko wrote: 2021-06-23 18:36 I’ve always thought that the most important part of the bounce is “the last ounce of the bounce” - the micro bounce as the bounce dies away. Is it still pistonic and free or does it tense up and begin to wobble like a jelly on a plate? The bass unit movement would likely give an indication.
Makes sense to me.
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Re: LP12 Bounce

Post by Defender »

good to know as mine is really pumping/moving. Its consistant with the bounce which I so far didnt got fully pistonic.So it probably indicates sideways movement/wabble ;).
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Re: LP12 Bounce

Post by John »

ThomasOK wrote: 2021-06-23 16:25 I have not heard of that one either. I'm not sure how accurate that is as the dynamics of the suspension are likely to be slightly different when the platter is not being powered by the motor/belt. My final test for the suspension is indeed to lightly bounce the suspension at the center of gravity whist playing a record. If the stylus doesn't stay in the groove then the suspension gets readjusted until it does. Higher compliance cartridges like the Adikt respond worse to side motions than cartridges like the Krystal and Kandid so the suspension needs to be just right. If the cartridge stays in the groove, shows no side to side motion of the body, and plays without noticeable modulation of the music with a small amount of bounce to the sub chassis then you have a very good suspension setup. I do generally show my customers this when they pick up the LP12, but I add the disclaimer: "I am a trained professional. Don't try this at home!" ;-)
I had my LP12 on the jig a couple weeks ago and when finished took a video of the suspension from the point of view I have when adjusting it. It also plays well while giving it a light bounce while playing a record. You might not be able to see the movement but the suspension is still moving the duration of the video..

https://youtu.be/43_lQvVI13k
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Re: LP12 Bounce

Post by matthias »

John wrote: 2022-09-10 19:09 I had my LP12 on the jig a couple weeks ago and when finished took a video of the suspension from the point of view I have when adjusting it. It also plays well while giving it a light bounce while playing a record. You might not be able to see the movement but the suspension is still moving the duration of the video..
https://youtu.be/43_lQvVI13k
Nice, what sub chassis do you have?
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Re: LP12 Bounce

Post by John »

matthias wrote: 2022-09-10 19:49
John wrote: 2022-09-10 19:09 I had my LP12 on the jig a couple weeks ago and when finished took a video of the suspension from the point of view I have when adjusting it. It also plays well while giving it a light bounce while playing a record. You might not be able to see the movement but the suspension is still moving the duration of the video..
https://youtu.be/43_lQvVI13k
Nice, what sub chassis do you have?
It’s a Greenstreet subchassis that I purchased in 2010. It was in production until recently when the owner stopped trading due to health reasons. Obviously it’s not as nice as a Keel but at a quarter the price a nice upgrade over the stock Cirkus subchassis. Some say it’s a Klone of the Keel but it lacks the three lands around the bearing mount, the integrated arm collar and the finish though anodized is not as nice overall as the Keel.
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Re: LP12 Bounce

Post by Defender »

this is bouncing really nice
it would be great to see if the theory with the pumping of the bass units works - meaning you place the needle on the record the platter is not turning and than you engage the bouncing-do your bass drivers move in and out or not?
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Re: LP12 Bounce

Post by ThomasOK »

That looks like a good, clean bounce.
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Re: LP12 Bounce

Post by John »

Thanks for the positive comments. This is the best I’ve gotten the suspension since I can remember. I took each spring/grommet off one at a time and cleaned them thoroughly with a toothbrush and Dawn detergent and placed them back in place. Working from a very level jig to a level resting place it maintained the bounce quite nicely.

I also played around with the dressing of the arm cable straightening it out more and getting it so as to not affect the bounce when plugged into the Ekos. Hopefully I’m good for awhile as I just replaced the cartridge recently with a Goldring rebuilt Asaka.

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Re: LP12 Bounce

Post by Defender »

happy for you but also kinda jealous as I never got my greenstreet audio bouncing nicely but its probably not the greenstreet audio‘s fault.
Did you ever had a chance to compare to a real Keel? If yes what do you think about the difference.
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Re: LP12 Bounce

Post by John »

Defender wrote: 2022-09-13 21:10 happy for you but also kinda jealous as I never got my greenstreet audio bouncing nicely but its probably not the greenstreet audio‘s fault.
Did you ever had a chance to compare to a real Keel? If yes what do you think about the difference.
After twelve years with the Greenstreet, I think it’s the first time I have the armboard situated pretty much square in the slot. Not exactly sure what I did exactly but it all came together rather quickly after cleaning and replacing the grommets and springs one at a time.

I now have the armboard level with the top plate. Because I have a pre-Cirkus version of the GS, I always ran the armboard a bit lower. During this latest play with the deck I found the arm cable was fouling with the baseboard when I put it in place. Raising the armboard to be even with the top plate alleviated the issue.

No, I haven’t done any comparisons nor ever heard a Linn Keel. Doing any meaningful comparison would be quite a challenge and one I wouldn’t act upon anyway. Better for me not to know.;-)
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Re: LP12 Bounce

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Hermann wrote: 2021-01-06 13:01 Many thanks to Mike for the topic. It gives me food for thought. All the years I never had problems to set up the LP12 correctly in terms of musicality. Since the Keel has been installed, I can't get the arm board to align in parallel at the same time and get a correct bounce. This is affecting the sound. The last setup did not work. When the board was misaligned I was almost happy. But that almost alone was enough to set up the LP12 again. This time the board was parallel with good bounce. Unfortunately the musicality suffered a bit.

Thomas and Fredrik's comments shed considerable light on the background. Many thanks for that.

When I do the next setup, these things will come into play. However, replacement parts such as springs, washers and screws are missing.

I followed on a hint from my dealer that turning the rubbers has a not so great effect on the bounce effect. His recommendation is not to move the rubbers with small turns, but if necessary, turn in large steps. However, did not work.

What I understand now is the dependency of the rubbers and springs in the right place is much more important than the turning. As well as the correct washers and screws.
I’ve gotten my suspension setup the best I ever recall since owning my one-piece Greenstreet subchassis which is a clone of the Linn Keel dimension-wise. For the first time the arm board sits perfectly square and parallel to the top plate. I’m beginning to think that aspect of setup is a big deal in obtaining a perfect pistonic bounce with no lateral movement and great micro level of bounce.

Prior to the Keel, the armboard attachment to the subchassis had play in it via the three screws that attached it to the arm board. The suspension was tuned for the best bounce and the armboard could be re-aligned after the fact for cosmetic purposes.

I’m curious regarding thoughts on this aspect and wonder if Keel owners have armboard setups that are parallel with the top plate? My latest version of the Linn LP12 Service manual is dated 1998 prior to the introduction of the Keel. Has Linn updated the service manual since? I’d like to secure a copy if possible.
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Re: LP12 Bounce

Post by sktn77a »

John wrote: 2022-09-10 19:09 I had my LP12 on the jig a couple weeks ago and when finished took a video of the suspension from the point of view I have when adjusting it. It also plays well while giving it a light bounce while playing a record. You might not be able to see the movement but the suspension is still moving the duration of the video..
https://youtu.be/43_lQvVI13k
Nice bounce. But I heard a single knock from the suspension (just like my LP12 does, only mine continues for 2-3 bounces).
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Re: LP12 Bounce

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sktn77a wrote: 2022-09-20 22:52
John wrote: 2022-09-10 19:09 I had my LP12 on the jig a couple weeks ago and when finished took a video of the suspension from the point of view I have when adjusting it. It also plays well while giving it a light bounce while playing a record. You might not be able to see the movement but the suspension is still moving the duration of the video..
https://youtu.be/43_lQvVI13k
Nice bounce. But I heard a single knock from the suspension (just like my LP12 does, only mine continues for 2-3 bounces).
There is a knock, but it’s at a high amplitude. I’m not too bothered by that and extremely pleased with how it’s bouncing with the arm board centered in the slot. Haven’t heard any comments on that aspect but I imagine it’s a good thing to have regarding setup of the suspension. I think it may go hand in hand with a good setup.
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Re: LP12 Bounce

Post by Hermann »

John wrote: 2022-09-17 17:49
Hermann wrote: 2021-01-06 13:01 Many thanks to Mike for the topic. It gives me food for thought. All the years I never had problems to set up the LP12 correctly in terms of musicality. Since the Keel has been installed, I can't get the arm board to align in parallel at the same time and get a correct bounce. This is affecting the sound. The last setup did not work. When the board was misaligned I was almost happy. But that almost alone was enough to set up the LP12 again. This time the board was parallel with good bounce. Unfortunately the musicality suffered a bit.

Thomas and Fredrik's comments shed considerable light on the background. Many thanks for that.

When I do the next setup, these things will come into play. However, replacement parts such as springs, washers and screws are missing.

I followed on a hint from my dealer that turning the rubbers has a not so great effect on the bounce effect. His recommendation is not to move the rubbers with small turns, but if necessary, turn in large steps. However, did not work.

What I understand now is the dependency of the rubbers and springs in the right place is much more important than the turning. As well as the correct washers and screws.
I’ve gotten my suspension setup the best I ever recall since owning my one-piece Greenstreet subchassis which is a clone of the Linn Keel dimension-wise. For the first time the arm board sits perfectly square and parallel to the top plate. I’m beginning to think that aspect of setup is a big deal in obtaining a perfect pistonic bounce with no lateral movement and great micro level of bounce.

Prior to the Keel, the armboard attachment to the subchassis had play in it via the three screws that attached it to the arm board. The suspension was tuned for the best bounce and the armboard could be re-aligned after the fact for cosmetic purposes.

I’m curious regarding thoughts on this aspect and wonder if Keel owners have armboard setups that are parallel with the top plate? My latest version of the Linn LP12 Service manual is dated 1998 prior to the introduction of the Keel. Has Linn updated the service manual since? I’d like to secure a copy if possible.
I'm sorry Johannes, had overlooked your post.

When the dealer did the conversion at the time, he hardly paid attention to the springs. He turned them three/four times and found it good. Of course the arm board was parallel, but the bounce wasnt perfekt and it didn't sound right at the first. The setup started again by myself. Again not parallel, but the LP12 played very well. Nevertheless, this feeling always remained. Although I found a good compromise, it resulted in a not quite perfect bounce. Setting a perfect bounce is easy to me, but at the same time keeping the board parallel seems to be my Achilles' heel.

I do setup this way. Put the LP12 in the jig, connected Radikal, switched it on and put a round spirit level on the spindle. Adjust the plate in such a way that the level bubble (when rotating) keep in the middle. I only get this condition with a slightly sloping armboard.

Some time ago I asked TomOK about changes to the top plate. Found mine to be fine. However, it is the only part that has been used since '96. It would be worth considering replacing them. Maybe that's how I get to the real point I want.
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Re: LP12 Bounce

Post by John »

I’d love to know what the trick is to get that armboard on Keel’s perfectly parallel, if in fact there is one. This would be helpful to know for next time I need to strip down the deck to install something like a new bearing. For now, my setup is perfect, sounding wonderful and the arm board is parallel. I’ve been really digging into my collection and listening to a lot of LP’s.

I read somewhere, I think it was a review that mentioned a 10 page setup/owner’s manual that came with the Linn Keel. If such a thing exists, I’d love to have a copy. Also, there must be a newer version of the Linn LP12 setup manual than the one I have which was from 1998. I’d love that as well.
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Re: LP12 Bounce

Post by sktn77a »

Is the armboard straight in the plinth when the arm cable is disconnected?
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Re: LP12 Bounce

Post by John »

sktn77a wrote: 2022-10-08 23:11 Is the armboard straight in the plinth when the arm cable is disconnected?
Yes it is. I setup the suspension with the arm cable unplugged from the tonearm. If the tonearm cable is properly dressed, it should have no effect on the suspension when plugged back into the tonearm.

https://youtu.be/43_lQvVI13k
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Re: LP12 Bounce

Post by sktn77a »

John wrote: 2022-10-09 12:19Yes it is. I setup the suspension with the arm cable unplugged from the tonearm. If the tonearm cable is properly dressed, it should have no effect on the suspension when plugged back into the tonearm.
Yes, it "shouldn't" but invariably does, if you don't do this for a living!
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