Perfect setup for AT-LP120 USB Turntable

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Quartz_Lock10729
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Re: Perfect setup for AT-LP120 USB Turntable

Post by Quartz_Lock10729 » 11 Apr 2018 18:48

BMRR wrote:
Quartz_Lock10729 wrote:Let me ask you gentlemen this, while I'm here...

If I have the LP120 with the stock felt slip mat, would I HAVE to remove it to take stylus force readings with a digital scale? I always leave the mat ON the platter when taking these readings, as it seems to MY eye that the scale is about the height of an average LP when the mat is on; is this not accurate?
Leave the mat in place. There's no reason to remove it. The only time you'd want to remove a mat or platter to take a VTF reading would be with a turntable that uses a spring to apply the correct tracking force. Your turntable uses a counterweight, not a spring, so there's no need to remove the mat.
Are you sure?

I only ask because nearly everyone says this is a matter of LP THICKNESS compared to the thickness of the scale tray -- you want the stylus to measure right where an LP would sit, and most people say this is not the right height if a platter mat is on (though I don't agree with it).

I never heard the counterweight/spring argument...

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Re: Perfect setup for AT-LP120 USB Turntable

Post by BMRR » 11 Apr 2018 20:27

I'm not going to swear it as gospel or declare it a law of nature, but I can tell you that I was curious about this a few months ago and I took VTF readings with no mat, one mat, and two mats (one stacked on top of the other) and they all came out exactly the same, down to the 100th gram.

chiz
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Re: Perfect setup for AT-LP120 USB Turntable

Post by chiz » 11 Apr 2018 21:52

It depends on the arm design and resulting centre of gravity.
This article explains it well:
https://www.tnt-audio.com/sorgenti/in_balance_e.html

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Re: Perfect setup for AT-LP120 USB Turntable

Post by BMRR » 11 Apr 2018 22:14

Thanks for that article. Excellent reading. This paragraph applies to the tonearms on my Technics turntables and most likely applies to the LP120 as well:

"The first arm type is the generic arm where all masses lie more or less on a horizontal line through the pivot, with the VTF applied statically, i.e. by moving the counterweight. The Rega RB-250 belongs to this categoty, as do the many arms on seventies and eighties Japanese consumer turntables. With a set VTF the arms center of gravity (COG) lies left of the fulcrum, but at the same height. This position makes the setup almost immune to misreadings of VTF when the arm is lifted."

(emphasis added)

Quartz, you can leave your mat in place. :)

Quartz_Lock10729
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Re: Perfect setup for AT-LP120 USB Turntable

Post by Quartz_Lock10729 » 12 Apr 2018 00:01

BMRR wrote:I'm not going to swear it as gospel or declare it a law of nature, but I can tell you that I was curious about this a few months ago and I took VTF readings with no mat, one mat, and two mats (one stacked on top of the other) and they all came out exactly the same, down to the 100th gram.
That would indeed be enough for me, so I suppose I'm just gonna keep measuring with the mat ON...

Interesting that so many enthusiasts, though, find that sometimes even removing the PLATTER ITSELF is the only way to get "suitable readings" from a scale...to me, this sounds way overkill and out of spec anyway (the record wouldn't be THAT thick to make that kind of sizing difference). As it stands, most just suggest ALWAYS removing a rubber, cork or felt mat...

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Re: Perfect setup for AT-LP120 USB Turntable

Post by Quartz_Lock10729 » 12 Apr 2018 00:05

BMRR wrote: Quartz, you can leave your mat in place. :)
While I don't really follow the specifics and science of that excerpt, I appreciate your putting my mind at ease with your statement, BM...

Can anyone explain this in a more straightforward, simple fashion (why it doesn't matter that the platter mat on a turntable such as the Technics SL1200 or Audio-Technica AT-LP120/1240 is left ON when taking digital VTF readings)?

chiz
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Re: Perfect setup for AT-LP120 USB Turntable

Post by chiz » 12 Apr 2018 00:28

Well that article I linked to is from a theoretical perspective and in reality the weight distribution of the headshell / cartridge may result in a centre of gravity very slightly below the pivot for the type of arm we are discussing.
So I did a quick rough test myself with the Technics arm and if the height of the measuring platform is say 4mm this may produce an error in the region of 0.5% or 0.01g for 2g VTF so nothing worth worrying about.

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Re: Perfect setup for AT-LP120 USB Turntable

Post by Quartz_Lock10729 » 12 Apr 2018 01:15

chiz wrote:Well that article I linked to is from a theoretical perspective and in reality the weight distribution of the headshell / cartridge may result in a centre of gravity very slightly below the pivot for the type of arm we are discussing.
So I did a quick rough test myself with the Technics arm and if the height of the measuring platform is say 4mm this may produce an error in the region of 0.5% or 0.01g for 2g VTF so nothing worth worrying about.
Thanks!

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USB for Denon Amp

Post by Royston1 » 16 Nov 2018 13:38

Can I blue tooth from my deck to my amp🤔please

lenjack
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Re: Perfect setup for AT-LP120 USB Turntable

Post by lenjack » 16 Nov 2018 23:27

AT has admitted that the antiskate didn't work right. It was corrected in new production as of January, 2017.

Boltman92124
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Re: Perfect setup for AT-LP120 USB Turntable

Post by Boltman92124 » 19 Nov 2018 21:38

The LP120 I've had for going on 4 years has some natural anti-skate when the arm is floated and AS set to zero. I think the spring is strong enough to work well under 2G vtf. Regardless, I've never had a problem with channel balance or distortion with any of my carts on the LP120. Proper alignment is much more important.

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Re: Perfect setup for AT-LP120 USB Turntable

Post by Boltman92124 » 19 Nov 2018 22:06

Quartz_Lock10729 wrote:
12 Apr 2018 00:05
BMRR wrote: Quartz, you can leave your mat in place. :)
While I don't really follow the specifics and science of that excerpt, I appreciate your putting my mind at ease with your statement, BM...

Can anyone explain this in a more straightforward, simple fashion (why it doesn't matter that the platter mat on a turntable such as the Technics SL1200 or Audio-Technica AT-LP120/1240 is left ON when taking digital VTF readings)?
I will say this, if you upgrade to the heavier counterweight sold by AT for the LP120, do NOT trust the scale on it after floating your arm and balancing. It is way off. Setting to 2.5g is really 3G with that heavier counterweight. Just get one of the digital scales by all means.

Quartz_Lock10729
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Re: Perfect setup for AT-LP120 USB Turntable

Post by Quartz_Lock10729 » 19 Nov 2018 22:21

Boltman92124 wrote:
19 Nov 2018 22:06
Quartz_Lock10729 wrote:
12 Apr 2018 00:05
BMRR wrote: Quartz, you can leave your mat in place. :)
While I don't really follow the specifics and science of that excerpt, I appreciate your putting my mind at ease with your statement, BM...

Can anyone explain this in a more straightforward, simple fashion (why it doesn't matter that the platter mat on a turntable such as the Technics SL1200 or Audio-Technica AT-LP120/1240 is left ON when taking digital VTF readings)?
I will say this, if you upgrade to the heavier counterweight sold by AT for the LP120, do NOT trust the scale on it after floating your arm and balancing. It is way off. Setting to 2.5g is really 3G with that heavier counterweight. Just get one of the digital scales by all means.
I do have a digital scale that I use...

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Re: Perfect setup for AT-LP120 USB Turntable

Post by marcolino7 » 26 Jul 2019 11:11

Hi,
I have an AT-LP140XP, looking at tonearm specification, it is eguat to AT-LP120USB.
Some know if there is a specific arc protractor for my turntable, or can I use the same of 120usb?

Many Thnaks