Damping a Technics SL1200 Tonearm

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Re: Damping a Technics SL1200 Tonearm

Post by cafe latte » 05 Dec 2019 11:40

scho2684 wrote:
05 Dec 2019 10:54
lola20 wrote:
05 Dec 2019 10:25
You got me curious. I put a multimeter on it and it conducts, zero ohms looks metal to me.
Mine also has zero Ohms (good point!) however it is still plastic.
Plastic with a metal type paint or cover, but only very thin...
The pattern that is suppose to look like it was made on a lathe would otherwise never have been achieved, hence the reason why the cross types on the 13/14/1500MK2 are having a smooth surface

Proof: I have melted a piece on a place that wont disturb me if I ever have to use it again...
It's plastic...

20191205_114532.jpg
Ok done tooth test, Metal conductivity test metal and scribe test metal it is metal full stop. Dont know it Technics changed but my two examples are metal for sure.
Chris

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Re: Damping a Technics SL1200 Tonearm

Post by scho2684 » 05 Dec 2019 11:43

cafe latte wrote:
05 Dec 2019 11:17
How hot did you make it melt? Cast aluminium melts easily.
I had the back of a 4mm drill heated up shortly...
The white stuff you see popping up underneath that coating on both sides of that mark is (melted) plastic...
cafe latte wrote:
05 Dec 2019 11:19
Interesting mine does not have a casting line like yours..
Chris
Visible on that first picture you mean?
Also on the 1400MK2 there is no casting line (which is a solid aluminium cross)
I cant do a conductivity test on it because its painted black, I will not scratch the paint away for this discussion ;-)

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Re: Damping a Technics SL1200 Tonearm

Post by lola20 » 05 Dec 2019 12:06

scho2684 wrote:
05 Dec 2019 11:43
cafe latte wrote:
05 Dec 2019 11:17
How hot did you make it melt? Cast aluminium melts easily.
I had the back of a 4mm drill heated up shortly...
The white stuff you see popping up underneath that coating on both sides of that mark is (melted) plastic...
cafe latte wrote:
05 Dec 2019 11:19
Interesting mine does not have a casting line like yours..
Chris
Visible on that first picture you mean?
Also on the 1400MK2 there is no casting line (which is a solid aluminium cross)
I cant do a conductivity test on it because its painted black, I will not scratch the paint away for this discussion ;-)
Seems you're right. No problem admitting. Another good reason to buy a 1200G.

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Re: Damping a Technics SL1200 Tonearm

Post by scho2684 » 05 Dec 2019 12:13

There is in my opinion absolutely no point in doubting the used materials for the 1200MK2 arm.
It has proven its rigidity, quality and use over the years and that plastic cross of mine, it sounds cheap when you say it but it feels very stiff, but light weighted...

If I haven't had to replace that 1210MK2 arm, I may have never guessed it, prior to that I also took it for granted that it was metal.
You only see/feel it when you have the naked cross in your hands...

My Techie days are long gone, but if I was in the position now to choose between turntables, a 1200MK2 and 1200G would never be in the same list of options...

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Re: Damping a Technics SL1200 Tonearm

Post by chamaruco » 05 Dec 2019 13:28

according to my technician and owner of "precision sound lab", this junction is plastic plated with Mylar
By putting on the auxiliary weight, you add a significant mass to the end of the stub, far away from the pillar of the arm.
Because the arm rotates on the pillar, and the mass is far away from that pillar, it starts to act like a flywheel (although that might be a bit of a overdone description)
so techincs were/are wrong letting us to add a additional weight?

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Re: Damping a Technics SL1200 Tonearm

Post by scho2684 » 05 Dec 2019 15:07

No, it is only what you are aiming at how to use that table...
If purely Hi-Fi on a "higher" level, this is starting to be a consideration...

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Re: Damping a Technics SL1200 Tonearm

Post by chamaruco » 05 Dec 2019 15:38

i'm stupid. on "higher level"... if i add an auxiliary weight i can take the main stock counterweight nearer to the pillar..as you said.am i wrong?

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Re: Damping a Technics SL1200 Tonearm

Post by scho2684 » 05 Dec 2019 16:02

No your not wrong...
Of course its the best compromise now, however it would be better to have as less distance possible between the pillar and counter mass....
So a better compromise would be a heavier counterweight sitting close to the pillar without the need for that auxiliary weight.
But then again, we are starting to talk about higher levels of hi-fi here, not sure if the 1200 and the used cartridge is even capable to make those differences audible...

I think that it would be quit difficult to notice the difference, point is that mass far away from the pillar is unwanted, none the less with a auxiliary weight at the end and counterweight close to the pillar, it may be a better situation than without that auxiliary weight and the counterweight therefore further away from the pillar...
That is my situation now as well with that 1400MK2

On my Jelco 750D I have now the heavier counterweight, sitting backwards almost against the pillar, that is the (I think better) alternative for the situation you see in my avatar (which was in my Techie time, now that arm sits elsewhere)

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Re: Damping a Technics SL1200 Tonearm

Post by cafe latte » 05 Dec 2019 23:28

scho2684 wrote:
05 Dec 2019 12:13
There is in my opinion absolutely no point in doubting the used materials for the 1200MK2 arm.
It has proven its rigidity, quality and use over the years and that plastic cross of mine, it sounds cheap when you say it but it feels very stiff, but light weighted...

If I haven't had to replace that 1210MK2 arm, I may have never guessed it, prior to that I also took it for granted that it was metal.
You only see/feel it when you have the naked cross in your hands...

My Techie days are long gone, but if I was in the position now to choose between turntables, a 1200MK2 and 1200G would never be in the same list of options...
Mine is metal for sure how old is your cross piece? Mine was last production seems odd that Technics went from plastic to metal normally companies go the other way round. I find it hard to believe they were ever plastic.
Re conductivity, no paint is 0.1 ohms across the whole piece an it is cold to touch of tongue (metal) and a tiny scribe on underside confirms metal and tooth tap test, again metal it is metal full stop.
Chris

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Re: Damping a Technics SL1200 Tonearm

Post by chamaruco » 06 Dec 2019 05:56

No way. Plastic + mylar

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Re: Damping a Technics SL1200 Tonearm

Post by scho2684 » 06 Dec 2019 06:22

cafe latte wrote:
05 Dec 2019 23:28
Mine is metal for sure how old is your cross piece? Mine was last production seems odd that Technics went from plastic to metal normally companies go the other way round.
That came from a 1996 table, delivered in The Netherlands...
The new replacement arm also had the same cross with a casting line...

That was a fun project by the way:
First-Last.jpg
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Re: Damping a Technics SL1200 Tonearm

Post by cafe latte » 06 Dec 2019 07:51

chamaruco wrote:
06 Dec 2019 05:56
No way. Plastic + mylar
It is metal tested it think what you like it is 0.3 ohms it is cold to touch it is metal on your tooth and scratching it it is metal end of story.
Chris

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Re: Damping a Technics SL1200 Tonearm

Post by cafe latte » 06 Dec 2019 07:56

scho2684 wrote:
06 Dec 2019 06:22
cafe latte wrote:
05 Dec 2019 23:28
Mine is metal for sure how old is your cross piece? Mine was last production seems odd that Technics went from plastic to metal normally companies go the other way round.
That came from a 1996 table, delivered in The Netherlands...
The new replacement arm also had the same cross with a casting line...

That was a fun project by the way:

First-Last.jpg
Great job, how long ago was the arm cross piece bought as both mine are metal for sure?
Chris

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Re: Damping a Technics SL1200 Tonearm

Post by scho2684 » 06 Dec 2019 08:09

There is no way to tell when that (complete) replacement arm was made, it was a refurbished one...

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Re: Damping a Technics SL1200 Tonearm

Post by cafe latte » 06 Dec 2019 08:11

scho2684 wrote:
06 Dec 2019 08:09
Ther is no way to tell when that (complete) replacement arm was made, it was a refurbished one...
My second arm I bought from Kab a month or two after buying my turntable so it was last production also.
Chris