LP12 Building Advice

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Topkho
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Re: LP12 Building Advice

Post by Topkho »

Hi everybody - I finally got a Richmont screwdriver… and I was digging in the archives of the forum to read some of the torque-related posts… wanted to make sure I interpret the posts correctly before I do anything. I have a PU7 tone arm on a Kore.

1) Arm collar to armboard: I understand these are the 3 big screws attaching the arm collar to the armboard: is it 1.6Nm? (Pu7 doesnt have slots for the tonearm pillar)
2) Arm height 2 small screws: is it 0.6Nm? Not sure about this one
3) the 2 motor mount screws (on the top plate): I have a Lingo 4, I understand it’s “only” 0.2Nm? Didn’t seem much

Thank you very much in advance.
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ThomasOK
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Re: LP12 Building Advice

Post by ThomasOK »

Hello,
The arm collar bolts are not likely to be near as high as 1.6Nm and with a standard laminated armboard could actually damage it. I have not worked with a PU7 so I don't have precise torques for that. The torque of those bolts varies with the arm collar and slightly with the armboard/sub chassis. For Ittok, Ekos and Basik it is .8Nm -2 notches on a steel sub chassis, for an Akito .6 +3, ProJect 9CC .6 +2 so that gives you an idea of the range you'd likely be in.

Around 1.6Nm is the normal arm height bolt torque for Ekos 2, Ekos SE and Akito but it varies a lot on other arms. A lot depends on the type of bolts used, some are metal, some metal tipped with plastic and some plastic. Arm height on the ProJect 9CC is only .4Nm -2, Krane .8, Jelco .8 +4, Ittok and early Ekos 2.6 and Basik Plus 2.6-1. So you can see there is a fair variety. Most Linn arms use a single screw and have a cutaway opposite the screw so that the collar makes contact on two lines and the screw - somewhat of a three point contact. Some arms with two screws use 2 different screws. So you are in for a fair bit of trial and error there but I would guess you will be in the lower half of the range with a unit using two screws.

Lingo 4 motor bolts are .6Nm -4. .2Nm is for the Radikal 2 motor bolts - quite a different fitting.

Good luck,
Tom
Topkho wrote: 2022-02-23 21:17 Hi everybody - I finally got a Richmont screwdriver… and I was digging in the archives of the forum to read some of the torque-related posts… wanted to make sure I interpret the posts correctly before I do anything. I have a PU7 tone arm on a Kore.

1) Arm collar to armboard: I understand these are the 3 big screws attaching the arm collar to the armboard: is it 1.6Nm? (Pu7 doesnt have slots for the tonearm pillar)
2) Arm height 2 small screws: is it 0.6Nm? Not sure about this one
3) the 2 motor mount screws (on the top plate): I have a Lingo 4, I understand it’s “only” 0.2Nm? Didn’t seem much

Thank you very much in advance.
The LP12 Whisperer
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Topkho
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Re: LP12 Building Advice

Post by Topkho »

Thank you for the very comprehensive reply… it’s time for some experiments indeed! I will report my findings… but first impressions is that the 2 screws for the arm height on the PU7 should be lower torque range indeed.
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Re: LP12 Building Advice

Post by Topkho »

ThomasOK wrote: 2022-02-24 00:17 Hello,
The arm collar bolts are not likely to be near as high as 1.6Nm and with a standard laminated armboard could actually damage it. I have not worked with a PU7 so I don't have precise torques for that. The torque of those bolts varies with the arm collar and slightly with the armboard/sub chassis. For Ittok, Ekos and Basik it is .8Nm -2 notches on a steel sub chassis, for an Akito .6 +3, ProJect 9CC .6 +2 so that gives you an idea of the range you'd likely be in.

Around 1.6Nm is the normal arm height bolt torque for Ekos 2, Ekos SE and Akito but it varies a lot on other arms. A lot depends on the type of bolts used, some are metal, some metal tipped with plastic and some plastic. Arm height on the ProJect 9CC is only .4Nm -2, Krane .8, Jelco .8 +4, Ittok and early Ekos 2.6 and Basik Plus 2.6-1. So you can see there is a fair variety. Most Linn arms use a single screw and have a cutaway opposite the screw so that the collar makes contact on two lines and the screw - somewhat of a three point contact. Some arms with two screws use 2 different screws. So you are in for a fair bit of trial and error there but I would guess you will be in the lower half of the range with a unit using two screws.

Lingo 4 motor bolts are .6Nm -4. .2Nm is for the Radikal 2 motor bolts - quite a different fitting.

Good luck,
Tom
Topkho wrote: 2022-02-23 21:17 Hi everybody - I finally got a Richmont screwdriver… and I was digging in the archives of the forum to read some of the torque-related posts… wanted to make sure I interpret the posts correctly before I do anything. I have a PU7 tone arm on a Kore.

1) Arm collar to armboard: I understand these are the 3 big screws attaching the arm collar to the armboard: is it 1.6Nm? (Pu7 doesnt have slots for the tonearm pillar)
2) Arm height 2 small screws: is it 0.6Nm? Not sure about this one
3) the 2 motor mount screws (on the top plate): I have a Lingo 4, I understand it’s “only” 0.2Nm? Didn’t seem much

Thank you very much in advance.
Reporting back on the PU7. On the 2 arm collar bolts, I tried 0.4nm, 0.5nm and 0.6nm.

First, to any doubter out there (if any), there’s an obvious difference which is musically significant between these 3 torques. No question about it. From 0.4 to 0.6 the sound becomes “louder” and more defined, more precise and ultimately a bit tense/analytical. Very obvious on strings. Right now I’m at 0.5nm because I like a relaxed and natural sound. I kept a low torque overall because the PU7 installation video mentioned to use only a “nick” of force, and 0.6nm started to harden, sound wise. I’m aware this is at the lowest in the range, and sometimes I feel it’s too low. Also the torque is not optimized in the other places so that’s another variable….

At the end of the day, it’s personal choice but that gives a sense of the importance of properly tuning your LP12. It reacts like a musical instrument with many significant tuning points that need to work in harmony. I definitely need to experiment more, and probably ask more questions :-)
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Re: LP12 Building Advice

Post by lejonklou »

Topkho wrote: 2022-02-25 22:16 Also the torque is not optimized in the other places so that’s another variable….
Good work, Topkho!

It's very worthwhile testing a few steps up and down from 0.5, which you found most musical so far. The interesting thing about torques (as well as many other parameters you can tune in a system) is that when you're way off, the difference is harder to tell than when you're getting close. So when you get down to the last step (one notch on the tool), you are likely to experience the biggest difference.

That the torques of other fasteners are not yet optimal doesn't matter. You can do them one by one, then when you've done the whole LP12 you can return to the first fastener you ever did and still find your original finding is correct. In other words: They don't affect each other. The only thing that happens when more and more fasteners are optimized is that it becomes easier to tell better from worse.
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Re: LP12 Building Advice

Post by V.A.MKD »

lejonklou wrote: 2022-02-25 23:58
Topkho wrote: 2022-02-25 22:16 Also the torque is not optimized in the other places so that’s another variable….
That the torques of other fasteners are not yet optimal doesn't matter. You can do them one by one, then when you've done the whole LP12 you can return to the first fastener you ever did and still find your original finding is correct. In other words: They don't affect each other. The only thing that happens when more and more fasteners are optimized is that it becomes easier to tell better from worse.
Excellent point, thank you for sharing your experience, Fredrik.
This is also valid for other equipment ... pre-amp, amp, int ... ?
Music First ...
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Topkho
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Re: LP12 Building Advice

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lejonklou wrote: 2022-02-25 23:58
Topkho wrote: 2022-02-25 22:16 Also the torque is not optimized in the other places so that’s another variable….
Good work, Topkho!

It's very worthwhile testing a few steps up and down from 0.5, which you found most musical so far. The interesting thing about torques (as well as many other parameters you can tune in a system) is that when you're way off, the difference is harder to tell than when you're getting close. So when you get down to the last step (one notch on the tool), you are likely to experience the biggest difference.

That the torques of other fasteners are not yet optimal doesn't matter. You can do them one by one, then when you've done the whole LP12 you can return to the first fastener you ever did and still find your original finding is correct. In other words: They don't affect each other. The only thing that happens when more and more fasteners are optimized is that it becomes easier to tell better from worse.
So now I went in more detail from above and below 0.5nm eg 0.5nm -1, -2 and -3… etc. There’s an inflection point between 0.5nm -1 and -2. In my view, the sweet spot is 0.5nm -1. It goes from dynamic but somewhat stiffer sound to more musical, and then it becomes too loose. The most surprising is that the sound feels just louder depending on the torque. Tried 0.6nm to double check myself and sure it’s stiff sounding.

There’s also a sense of satisfaction to be able to assemble the LP12 components with the “click” on the screwdriver giving you a torque level that is reliable and repeatable vs just a bunch of random torques eg the infamous “finger tight”. Especially you know (and can easily demonstrate and repeat) that the sound is impacted.
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Re: LP12 Building Advice

Post by ThomasOK »

Topkho wrote: 2022-02-27 18:37
lejonklou wrote: 2022-02-25 23:58
Topkho wrote: 2022-02-25 22:16 Also the torque is not optimized in the other places so that’s another variable….
Good work, Topkho!

It's very worthwhile testing a few steps up and down from 0.5, which you found most musical so far. The interesting thing about torques (as well as many other parameters you can tune in a system) is that when you're way off, the difference is harder to tell than when you're getting close. So when you get down to the last step (one notch on the tool), you are likely to experience the biggest difference.

That the torques of other fasteners are not yet optimal doesn't matter. You can do them one by one, then when you've done the whole LP12 you can return to the first fastener you ever did and still find your original finding is correct. In other words: They don't affect each other. The only thing that happens when more and more fasteners are optimized is that it becomes easier to tell better from worse.
So now I went in more detail from above and below 0.5nm eg 0.5nm -1, -2 and -3… etc. There’s an inflection point between 0.5nm -1 and -2. In my view, the sweet spot is 0.5nm -1. It goes from dynamic but somewhat stiffer sound to more musical, and then it becomes too loose. The most surprising is that the sound feels just louder depending on the torque. Tried 0.6nm to double check myself and sure it’s stiff sounding.

There’s also a sense of satisfaction to be able to assemble the LP12 components with the “click” on the screwdriver giving you a torque level that is reliable and repeatable vs just a bunch of random torques eg the infamous “finger tight”. Especially you know (and can easily demonstrate and repeat) that the sound is impacted.
Yes, I have generally found that as the torque gets too high things get harder and stiffer, what a friend referred to as more CD like. When it is too low things get soft, loose and sluggish. When you get it right everything seems to come together: it has a more tuneful quality, the rhythm moves along better and everything is more musically integrated. It sounds like your .5Nm -1 is that place on your arm. One thing I will note is that I don't use numbers like .5Nm on the SR driver. Why? Because there isn't a marking on the odd decimal points like .5 or .9Nm. You are basically guessing where .5Nm is as it is halfway between .4 and .6. So in order to have consistency when Fredrik, Paolo and I started sharing torques I recommended we standardize on going to the nearest actual mark and counting up and down from there. So your .5Nm -1 might also read as .4Nm + 5 or 6 or 4 but using that numbering you can be sure you, and anyone else using the same settings, are always using the same torque.
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