Vintage DD turntables. Are we living dangerously?

Nandric wins "Funniest Post" award. The rest of you can hand in your computers.
Henry, are you confirming that the data posted by Fremer come from the Feickert tools? I am sure he does not keep it a secret, but I cannot find where he says what instruments he uses. If the cost is reasonable, I would love to purchase the equipment just to test my 5 turntables.

Results for a DD will be heavily dependent upon the accuracy of calibration of the particular unit under test. That’s where guys like JP come into the picture. JP’s homebuilt chip for the Mk3 is more accurate than the original chip, but at a level where we are not sure it could be heard (perhaps also "surpassing [the accuracy of] measuring instruments"). Or maybe JP has done a listening test by now that does reveal differences. In other words, if one sample of a Mk3 is less accurate than one sample of a TT101, it proves nothing unless we know the state of tune of those two units.

I did run my Mk3 with a borrowed Timeline, and it was spot on at about 10 feet projection, but with "only" one tonearm and cartridge playing music. The friend who lent it to me owns a very expensive belt-drive. When he demonstrated the Timeline to me on his system, he literally had to get up and run to the motor controller about every 5 minutes so as to prevent the reflection from marching all around the room. As it was, it marched about 2-3 feet in minutes. He subsequently complained about the speed problem to the manufacturer who promptly supplied him with an "upgrade" to the motor controller.  In fairness, that did help the speed problem.  I think the Timeline is over-rated and overpriced, nevertheless.

http://hifiheaven.net/shop/Phoenix-Engineering-RoadRunner-Tachometer-for-all-Turntables

I install these in my DP80 and DN308 rebuilds - they display to the third decimal point.  Whats the point of building a super accurate turntable if one cannot show it :-)  

http://pbnaudio.com/audio-turntables/vintage-direct-professional/dn308

I could not help but notice that a very popular BD table with two platters have a similar display device - it however only display with one decimal point :-) :-) :-) 

I have the Time line too use it at shows to demonstrate the accuracy of the GrooveMaster Vintage Direct Tables

Good Listening 

Peter

Technics claimed the SP-10MKIII would maintain speed with up to one thousand tonearms tracking at 2 grams each.

Sure, look at this photo from the 1976 Japan Audio Fair during the presentation of the Technics SP 10 mk2 what it could do without speed variations; The MK3 is even an even more powerful engine.


http://i949.photobucket.com/albums/ad331/marika-johnson/AA.jpg



@Halcro     ok  ;)

"Technics claimed the SP-10MKIII would maintain speed with up to one thousand tonearms tracking at 2 grams each."

The manual for my SP-10 Mk2A quotes maintained speed "even with a load torque up to 5 kg-cm (4.3 lbs. in.)"  That's only 500 tonearms tracking simultaneously at 2 g. each.  So obviously a very inferior performer.  ;^)

Halcro
re the 2 tonearm test.
Actually I would be surprised if any of the flag ship  DD TTs from that era failed this test.
Feedback and sufficient motor torque is all that is needed.
re the SP10 MK3, I don't run 2 arms, but I did a timeline test playing a record while forceably applying a carbon fiber record cleaning brush.
The dot did not move 3.7 meters away.
Not very scientific, I know,  but it is possible to apply much more torque this way than with a second arm.
It is also possible to significantly modulate this torque, which I did.
 No movement.

cheers