Installing Trampolin 2

sommerfee · Post by **sommerfee** » 2007-05-22 18:39

The Trampolin2 has the well-known hole located under the tonearm, but this time it's covered by a metal plate. Should this be taken off?

And where to connect the ground cable?

ThomasOK · Post by **ThomasOK** » 2007-05-22 21:51

In my experience there should be no need to remove the cover with a Linn tonearm in most setups. The arm/subchassis would have to move a great deal to bottom out on the Trampolin 2. I just can't see it happening in normal use. Since having the cover in place helps keep acoustical energy out of the turntable it seems to me to be the way to go. That said I have not actually tried it both ways so I can't comment from actual experience whether it is more tuneful or not.

The ground cable should be connected to the front bolt that holds the top plate to the plinth where the ground from the subchassis is connected. Simply put the extra washer on the bolt, then the ground wire and then the additional nut and tighten it up. I have been tightening it so that the wire points towards the back of the turntable - this causes the wire to make a nice, big loop which should keep it out of the way of the subchassis.

These recommendations are based on my experience with a few of these so far - YMMV.

Post by **lejonklou** » 2007-05-22 22:35

I disagree. Having installed Trampolin/2 four times now, I have always had to remove the metal cover under the arm. Otherwise the arm will hit it when the suspension moves more than just a little.

I have been told the reason this cover exists is due to legal issues, not performance. The first Trampolin/2's did not have it, but Linn were then forced to add it to comply with the rules.

Regarding the ground cable, I don't really understand the need for the extra washer. Why not simply nut - wire - nut?

ThomasOK · Post by **ThomasOK** » 2007-05-22 23:13

lejonklou wrote:I disagree. Having installed Trampolin/2 four times now, I have always had to remove the metal cover under the arm. Otherwise the arm will hit it when the suspension moves more than just a little.

That's interesting, I'll have to double-check my setups. I bounced them the amount I normally do for testing (certainly more motion than they would see while playing a record) and did not notice any bottoming out. I'll try it again and see what happens.

lejonklou wrote:Regarding the ground cable, I don't really understand the need for the extra washer. Why not simply nut - wire - nut?

My only guess here is that some of the nuts Linn use have rounded tops and plastic inserts which might not make as good a contact with the eyelet on the wire. With the mill spec nuts it shouldn't be a problem but Linn don't generally use them on the post where the ground goes. On the newest LP12 I set up they had the all metal nuts on the springs but the ones with encapsulated plastic on the top plate posts. To be honest I just figured that if Linn put the washer in the kit they felt there was a reason for it to be used so I went ahead and used it.

Moomintroll · Post by **Moomintroll** » 2007-05-23 08:52

I was told that the cover was there to satisfy safety regulations in Canada. Mine is off.

I couldn't see the point of the earthing washer either - it won't affect the sound.

'Troll

Post by **lejonklou** » 2007-05-23 11:25

ThomasOK wrote:I bounced them the amount I normally do for testing (certainly more motion than they would see while playing a record) and did not notice any bottoming out. I'll try it again and see what happens.

Just a note to those unfamiliar with LP12 adjustments: This is not an issue where there is an absolute right and wrong, as it depends on how high you set the suspension and how high the arm is mounted in the arm collar. This varies between different LP12-arm-cartridge combinations.

I am quite certain there is no difference in performance between having this cover fitted or not.

ThomasOK · Post by **ThomasOK** » 2007-05-25 17:23

A quick note and certainly not definitive. I checked my own turntable and it takes quite a bit of force bouncing the subchassis up and down to get it to bottom out on the cover for the hole. It is beyond the amount of bouncing I would normally do for testing and well beyond the amount of movement it would see while playing a record (unless you attach a butt-kicker to your turntable stand :D ).

None of the five Trampolin2s I have installed have had any problem with bottoming so far - most were with Keel/Ekos SEs but two with Ittok/Adikt. I don't have any of them to hand so I was only able to check on my own unit (Keel/Ekos SE/Akiva). I do have two more to install within the next week or two so I will double check on them and let you know what I find. I may even do something radical and listen to it both ways and see if I can hear a difference

.

Fredrik, considering your last comment I wonder if you think it would be a good idea to start a topic on LP12 setup techniques. I know some of us have some techniques that are not easily shareable like torque settings, etc. But I wonder if enough of the people on the forum would find it of interest to see a thread talking about things like suspension height settings, cartridge setup, cable dressing, etc. Let me know what you think.

Post by **lejonklou** » 2007-05-25 19:09

I have also checked and I can just barely fit the cover on mine. Large movements means it bottoms out, so it's staying off. I might set my suspension a bit lower than you, perhaps? Or have the arm height a bit lower (I set it by ear so it varies slightly with each cartridge).
In any case, I think this is a non-issue.

LP12 techniques sounds fine, if people are interested.

ThomasOK · Post by **ThomasOK** » 2007-06-06 22:03

Well, I wouldn't have believed it if I didn't hear it myself but I have to say that the new Trampolin sounds better with the cover off! I just put a Trampolin 2 on the owner's LP12 and I A/Bed it with and without the cover and was surprised to find a worthwhile improvement in the tunefulness with it removed. I did the A/B twice just to double-check and both times I preferred the cover off. It is fairly easy to remove the cover with the Trampolin in place so it is not hard to do an A/B. It is a little trickier to put it back on but it can be done without too much trouble if the table is in a jig.

Our owner removes the cueing device to improve the sound so I did it on this new LP12/Keel/Ekos SE/Akiva and I have to say any difference was quite slight. Removing the cover from the Trampolin was a significantly larger difference.

I do agree that I can get the arm plug to bottom out with fairly large movements. With the way I set up an LP12 - top of the armboard flush with the top of the plinth, Ekos armtube essentially parallel to the record, platter level with the plinth - I do find it takes some fairly large movements to make it hit. But since it sounds better off it really doesn't matter.

It looks like I'll be taking that cover off my Trampolin at home tonight.

Post by **lejonklou** » 2007-06-07 12:56

Thank you for testing and reporting this, Thomas!

I agree that the removal of the lift assembly makes a very small difference to the sound. I took if off my Ekos 2 and the difference was minimal (if you don't tighten the arm height screw to exactly the same torque as before, you won't be able to evaluate it as that screw makes a bigger difference). On the Ekos SE I have decided to keep it on.

On Ittoks, where the arm lift lever can rattle because it is not damped, the difference is bigger. I would say worthwhile in case you never use the lift.

ThomasOK · Post by **ThomasOK** » 2007-06-21 18:22

Just another update. I just installed a Trampolin2 and a Cirkus upgrade on a customer's LP12. He owns an Ittok II with the standard cable (molded plastic plug on the arm end) and an Asaka cartridge. On this table the arm was so low that the plastic plug would have been pushed upwards by the cover plate on the Trampolin2 if it had been in place!

So there clearly are cases where there is not enough clearance with the cover plate in place. As I said in my last post, it sounds better off anyway. So the best advice is to leave the cover off in all cases.

Tony Tune-age · Post by **Tony Tune-age** » 2010-08-14 20:13

ThomasOK wrote:Just another update. I just installed a Trampolin2 and a Cirkus upgrade on a customer's LP12. He owns an Ittok II with the standard cable (molded plastic plug on the arm end) and an Asaka cartridge. On this table the arm was so low that the plastic plug would have been pushed upwards by the cover plate on the Trampolin2 if it had been in place!

So there clearly are cases where there is not enough clearance with the cover plate in place. As I said in my last post, it sounds better off anyway. So the best advice is to leave the cover off in all cases.

Interesting information, I was able to play ablbums with the dust cover on and completely closed. I wanted to keep off as much dust as possible :!: And there was enough clearance for the tonearm to function properly as well. However, the turntable sounded much better with the cover completely removed 8) . Lesson learned for sure :!: