Linn Bedrok LP12 Plinth Upgrade

mylogic

I found the Datum II and IIs silver wire version, it appears they changed the mount from a threaded post and nut below deck to a Jelco Type surface mounted 3 screw base plate, am I correct about that? I prefer removable headshells. They do not mention it, but I think I read that the Datum II and IIS includes azimuth adjustment at the end of the arm, I see what look like 2 screws

I just mounted my new to me Vintage JVC Victor UA-7082 11-1/8" long arm. It's counterweight section's rubber isolation sag was properly repaired. The anti-skate adjustment is the smoothest I ever encountered, like the Acos Lustre GST-801 it is easy to adjust while playing/listening, although I prefer setting it while lowered onto the smooth side of my alignment disc

. After releasing the JVC height locking ring, then you can place the stylus and adjust the height while playing, however final locking is a two handed job, not while playing.

My Acos Lustre GST-801 which I learned about here is my favorite arm, easy to release/adjust/lock everything while playing: height/tracking force/anti-skate. I use an AT headshell with azimuth adjustment. I wish they made a long version of it.

I just noticed, the Logic Datum II looks to have a very compact/short length counter-weight section, it might fit on the left side where my Mission/Jelco 774 is, I will need the measurement from pivot to the rear end, and I need to double check the overall height for clearance when the dust cover is on

This still shows the 12.5" blackbird arm, I removed it, spun the armboard around 180 degrees, and used the original hole that the 45 adapter is show in, where the original 7082 arm was.

Alignment LP, one side smooth for observing/setting anti-skate

@elliottbnewcombjr

Datum II & IIs

The Datum I was manufactured by Syrinx and up to that point had threaded posts and nuts to mount.

Logic aquired Syrinx and made in house the Datum II & IIs with the three point mounting collar. They mounted both Datum’s on their DM101 and Logic Tempo turntables.

Mounting hole 30.5mm

Effective length 228mm

Pivot to spindle 210.7mm

Overhang 17.3mm

Azimuth is adjustable by two bolts.

You are correct the counter balance is very up close to the pivot due to the tungston counter weight.

All of the Syrinx arms…LE1, up to the Datum I had the same measurements and these were carried over to the Logic produced Datum II & IIs

One thing to note is that when Logic folded the companies stock was bought by Manticore Systems Engineering. Their well liked Mantra turntable was a leading model in the UK. The later Datum IIs arms were modified to their new specs under the MSE logo which appears on the arm pivot. Superior bearings and improved external finishing also cured the anodising effect of UV in earlier models.

A Datum IIs with the silver wire was considered better than the Linn Ittok LV3 Mk2 and considerably less expensive. The Datum I, Syrinx PU2 and PU3 models were claimed by some to be ‘’Ittok Killers’’ within their individual timeframes.

Search the ‘’Vinyl Engine’’ archives further to confirm this information if you wish. l own a few Syrinx arms so l am sure l have given you the correct info.

watch the video

https://www.youtube.com/watch?v=SqP4eHBSlI4&t=2s

minute 5, the shaft simply drops into the bearing with no resistance

clunk

he removes it, adds a few drops of oil, it simply drops in again

clunk again.

There is no way in the world that that can be considered fine tolerances. and what makes the clunk noise? shouldn't it be zero contact floating on oil?

minute 6, drop the tonearm post in the mount indicates no close fit either.

This video is shocking. The guy has no idea of how to put a turntable together.

Not only is the bearing housing and shaft as loose as a goose,

 he puts no oil on the spindle before insertion.

In tight tolerance bearings you always smear oil around the spindle before insertion to avoid scouring when inserting.

Unbelievable - and the video reminds me of what a rube Goldberg contraption the Linn is along with the low tech bearing and motor the size of a weenie.

@dover

The guy is Gordon Inch at Linn. I found him to be very approachable.

He’ll no doubt be interested to hear your views on turntable set up.

https://www.facebook.com/share/1Bx1f5zKML/

Let me know how you get on.