LP12 torque tests with soundclips

Efraim roots · Post by **Efraim roots** » 2013-01-07 22:07

Hello!

I have been playing with my torque wrench today. I tried some different settings with bearing to keel screws. I would love to hear your opinions about which soundclip is best. They are not listed in order, I tell you the details after we get some suggestions of the best sounding clip.

Please listen or download from this link, it's 4 clips named 69, 70, 71, 72:

https://soundcloud.com/ital-light

Swedish folk music, I don't think you heard this tune before ;-)

Charlie1 · Post by **Charlie1** » 2013-01-07 23:33

Nice idea Efraim. I did download them and compare, but I think my laptop and speakers are not up to this one. I couldn't really hear any difference. Normally, it's OK, so perhaps the change is very small. Maybe try again with headphones tomorrow. Sorry.

Efraim roots · Post by **Efraim roots** » 2013-01-08 00:38

Thanks for your try, it may be hard with the chosen piece of music. It's only a man playing accordion (right word?) in his kitchen. It's a swedish folk music record with older men playing old melodies with harmonica and accordion. I chose the this tune because it's so different to what normally listen to and for me that works better when doing tune dems.

I agree differences are quite small but I still have my favorite and feel pretty secure, but it would be interesting if you guys come to the same conclusion or not.

Charlie1, please try again, with a focused mind and headphones I would think you spot some differences :-)

Post by **lejonklou** » 2013-01-08 08:05

I like clips!

Will listen in a couple of days.

Charlie1 · Post by **Charlie1** » 2013-01-08 16:07

Efraim roots wrote:Charlie1, please try again, with a focused mind and headphones I would think you spot some differences :-)

Sorry Efraim, tried with headphones, but just can't do it. I'm sure it would be really obvious in front of the deck. Usually I can pick one, but not this time.

anthony · Post by **anthony** » 2013-01-08 17:08

Well I tried using the summary 4 short extracts, and find the first one the best, the second the worst, the other two somewhere between.

I think this means 69 is the best, 70 worst, 71 is probably 2nd best

ThomasOK · Post by **ThomasOK** » 2013-01-08 18:18

This should be interesting. I don't know if I'll have time to listen to them on a real system for a while as I am getting ready to fly to Las Vegas for the CES later today. I did download them so I can try it sometime.

I did a quick listen through the speakers in the store iMac, not the most reliable way to evaluate these things, and I liked the one marked 69 the best and 71 the next best. The other two I didn't try to rank, just didn't like them as well.

When I have a chance to do a Hi-Fi listen I'll report back but it probably won't be until next week.

Post by **lejonklou** » 2013-01-09 11:51

69 feels most in tune for me. I just feel that left and right hand are helping one another on that one, creating something bigger than their respective parts.

Not sure which is number two. They all have something that doesn't feel right. I didn't think 70 stood out as the definite worst.

Efraim roots · Post by **Efraim roots** » 2013-01-09 19:41

Very interesting, thanks for your contributions!

I have come to another conclusion actually, and today a friend listened with me and he came to same conclusion as me. I had not told him any details about the clips or about my own feelings about which is better.

I let this go for another day or two before I write down the details of testing. Please feel free to listen more and make your contributions.

Efraim roots · Post by **Efraim roots** » 2013-01-09 20:03

Lejonklou:

They all have something that doesn't feel right.

This is making the comparison harder I think, it's not a very optimized LP12 we are listening to. The LP12 is in the jig without trampolin and the jig is standing on top of harmonihyllan, the bounce is also quite 'off'.

Hopefully within some time and help from this forum and it's members the LP12 is going to sing!

Efraim roots · Post by **Efraim roots** » 2013-01-12 09:37

Ok,

the tests was going like this. I had read in another thread that bearing to keel screws is best set to a torque between 3.7-3.9Nm. Lejonklou recommended in this thread to start at 3.7 and go up, so that's what I did.

Personally I felt that 3.7Nm (69) was better than what I had before when it was torqued by feeling. Next step was better (70), after that (71) I felt it's getting worse, so I tried to go back one step (72) and felt this was the sweet spot. My feeling about clip 72 is that the timing is best and melody and rhythm are most nuanced and controlled.

clip 69 is 3.7nm
clip 70 is 3.7+2notch Nm
clip 71 is 3.7+4notch Nm
clip 72 is 3.7+3notch Nm

My conclusion is to set bearing to keel at 3.7+3notches Nm. What do you think? Could I have got it right or should I just start over again?

I have the same torque wrench as Lejonklou and Thomas, and as reference I can say that tonearm screw on EkosSE sounds best at 1.6+2notches Nm with my tool, that one I'm sure I got right, tested several times.

Thankful for any help!

Efraim roots · Post by **Efraim roots** » 2013-01-18 19:55

I'm still pretty confident clip 72 is the best. Do you think I am wrong please tell me so, I really want to get it right. I probably have to do the tests again with another tune.

Regarding the torque tests, I find the screw heads get easily rounded when I use a Hex3 bits with my tool. I used the torx bits of same size instead which gave me better grip in the screw head. Is it my technique or why is the hex3 bits rounding the screw head? (Hex 4 is too big)

What's the best bits to use for bearing screws in your experience?

Post by **lejonklou** » 2013-01-18 21:57

I did listen again to clips 69 and 72 on my computer, but felt pretty much the same as before.

If the quality of the clips is high enough (I can't really tell if it is, but I believe this is crucial for this method to work), maybe you should use another piece of music and see what we think of that? Personally, I never use the first song I come across when I "tune stuff". I try a bunch of songs and use the first one that I emotionally understand in that moment. If I understand the song, the tuning becomes quick and easy. But if I try using a song I don't really connect to, it can be difficult to tell better from worse. Do you see what I mean?

Regarding the torques, did you go any higher than 3.7+3? There are usually multiple peaks, which means that even if 3.7+4, +5 and +6 are worse than +3, another peak can appear higher up.

Efraim roots · Post by **Efraim roots** » 2013-01-18 22:40

lejonklou wrote:I did listen again to clips 69 and 72 on my computer, but felt pretty much the same as before.

If the quality of the clips is high enough (I can't really tell if it is, but I believe this is crucial for this method to work), maybe you should use another piece of music and see what we think of that? Personally, I never use the first song I come across when I "tune stuff". I try a bunch of songs and use the first one that I emotionally understand in that moment. If I understand the song, the tuning becomes quick and easy. But if I try using a song I don't really connect to, it can be difficult to tell better from worse. Do you see what I mean?

Regarding the torques, did you go any higher than 3.7+3? There are usually multiple peaks, which means that even if 3.7+4, +5 and +6 are worse than +3, another peak can appear higher up.

Quality of clips is really good in this case, they are recorded to a portable digital recorder of high quality that's been chosen carefully. My vinyl recordings (original press) usually outperform the best available CD versions of same tunes. They are recorded in 24/96.

That's very good advice regarding the selection of tunes for tune dem. Emotional understanding is what we want!

I went up to 3.7+4notches Nm. I will try this again with another tune and keep going higher.

Any advice regarding the best suitable bits?

Charlie1 · Post by **Charlie1** » 2013-01-18 23:21

Hi Efraim, this thread might be handy for you too.
http://www.lejonklou.com/forum/viewtopic.php?t=487

ThomasOK · Post by **ThomasOK** » 2013-01-22 19:09

I would also recommend trying a bit higher up as well. My finding for best torque on the bearing housing to Keel is 3.8Nm +1 notch which closely correlates with the findings of some others. Again, of course, your driver may be a bit different than mine.

Efraim roots · Post by **Efraim roots** » 2013-02-08 23:33

Thanks Charlie for your link, some useful info for sure.

Also thanks to Thomas for providing your best torque value.

I have now investigated further regarding bits and of course a hex3 bits is the right one, I probably should not have used the torx bits because my screws got pretty ugly and dysfunctional. I should have used a longer more slender bits to get optimal contact in the screw head to avoid rounding. I actually find it difficult to tighten these screws because they are not very ease to access and and also the torque is high. About every other screw on the sondek is easier to work with imo. I would like to warn others who experiment that the screws which also is of a softer metal type could get rounded which could lead to big problems. I had to replace my screws with new ones and this time I took the keel out of the deck and just used the value Thomas mentioned without testing. I may experiment further in the future but for now I don't want to mess up again.

ThomasOK · Post by **ThomasOK** » 2013-02-09 16:33

There are certainly some fittings on the LP12 that are in danger of deformation if they are readjusted too many times. The bearing housing bolts are one of them and I agree they are the most difficult to test, not least because of having to remove the inner platter each time. There should be no problem retightening them a few times and I'm sure using a Torx head was part of the problem you had, but it is interesting to note that Linn includes a new set of these bolts with the Keel.

The motor mounting bolts on the AC motor are another difficult one as the torque is enough to strip the head of the small hex bolts used. I tighten them from underneath but that isn't particularly easy either. For one thing it needs a 5.5mm socket which, as Fredrik and I both found out, isn't the easiest just to pick up at your local hardware store. Even worse the space between the bolt and the motor is pretty small requiring a socket with a fairly thin wall. In the end I had to take a regular 5.5mm socket and have a friend machine down the tip so it would fit! Definitely a tool I am careful not to lose.