Vintage DD turntables. Are we living dangerously?

Lewm. Yes the 701 has the EDS-1000 brushless coreless motor.

The hall-effect electronic drive motor operates independently of AC line frequency and voltage fluctuations, so the 701 platter speed never fluctuates. An entirely different kind of motor, designed expressly for the 701, and a very innovative approach to the problem of resonance. Instead of the familiar, high speed AC motor, the 701 has an all electronic, low speed motor, with feedback-controlled speed precision. Because this motor rotates at the record speed, 33 1/3 or 45rpm, the need for speed reduction systems such as friction idler or rim belt is eliminated. Instead, the platter is rotated directly by the motor, and the record spindle is the top of the motor shaft. The 701 motor is so quiet and free from vibration that it does not require any isolation mounting, but is mounted directly to the chassis.

ORIGINAL DUAL 701 FACTORY SPECIFICATIONS:

Motor: Electronically Servo Driven
Wow and flutter: < 0.03%
Rumble: Unweighted: > 50dB; Weighted: > 70d
https://www.lencoheaven.net/forum/index.php?topic=28237.msg380130#msg380130
http://unepassionaudiophile.fr/platine-base-dual-eds-1000/
https://www.vinylengine.com/library/dual/701.shtmlhttps://www.vintageshifi.com/repertoire-pdf/Dual.php

@lewm the actual calibration takes me about an hour all-in these days.  Repairs, done right, are where the cost is.  

News about my two Victor TT-101 that i bought in 2017.

1) I have reported earlier in this thread that first of them purchased from the original owner as "working" appeared to be defective on the first test on arrival. We discussed the issue here few years ago. I gave up on expensive service abroad with expensive shipping, and could not find anyone locally to take a risk on repair. So i put this unit aside in my living room and it was there from the summer 2017 til the summer 2019. When tried it again in 2019 it was WORKING! Magic? I did nothing, but i think a constant temperature in my room and good energy somehow cured my TT-101. I tried it several times on 33/45 with pitch up and down and it's just fine, it was constantly on for 48hrs in each session many times. And i can't detect a problem i saw on arrival 3 years ago. Maybe it was just a stress after transportation, maybe it was stored for some time by original owner in his basement, who knows. But stayin' unplugged in my room for 2 years years something happened and i think it's because of the right temperature in the room.  

This unit is quiet, easily working for 3 days non stop and right now still spinning.

I think it's a good sign, so i ordered a plinth for this turntable. 

2) I also mentioned another sample that i bought later, i thought i'm bought my second sample for parts as a donor. The unit i bought was described as defective from the start. I also mentioned this problem before in this thread. The situation with this 2nd sample was different that with my 1st sample. When i got the unit it was working on arrival, but i had to touch the platter by hand on the start. Then rotation was stable for a long time, i think i already tested the unit for a few nights nonstop in 2017. Anyway i put it aside next to my 1st unit and it was in my room for more than 2 years. 

Last week a friend asked me to sell him one of my Victor TT-101, i replied that i will check both and i did. I forgot which one is 1st and which one is 2nd, because visually they are identical and looks MINT-

Now i figured out which one is 1st and which one is 2nd after investigation of my old invoices etc. 

I've noticed common problem for some vintage direct drive i've bought last year (Denon DP-80 and Technics SP-20). Nothing serious and very easy to fix, but on the first test looks like disaster. The motor under the platter on Denon DP80 and Technics SP20 is fixed by several screws, sometimes they are not screwed properly or simly a bit loose (because the turntables are 40 y.o.). When those screws are loose the motor and spindle can be off-centered and as a result the platter is off-centered too. When the platter is slightly off-centered the edge of the platter can grind the edge of the turntable body. As i said it is very easy to fix, all you need is to loose the screws, turn the platter on, check the position, the remove it and fix the screws on the motor. 

This is why my 2nd Victor could not start without a touch of my hand. When i removed the platter to fix the screws i realised it was a bit off-centered, so i fixed it and problem gone. Turntable start spinning when i just press the start button. The problem is gone! 


BOTH SAMPLE WORKING!
BOTH TT-101 ARE FINE NOW, FINGERS CROSSED. 

The minor difference between my 1st and 2nd units is:

-when my ear is near turntable i can barely hear pulsation coming from the electronics inside the TT-101, but only when 33 or 45 rotation is "on". When my TT-101 is in standby mode i can rotate the platter manually and there is no sound, so this is not mechanical sound, it is a very very low level pulsation from the electronics. Not sure what it is? 

Another sample is dead quiet, nothing like that. But i think stop button must be calibrated, it works fine, but after the platter stopped there is a backward move, very little. For example i've seen it before on Technics SL1200mk2 and it was fully adjustable, it is a function of "stop" (slow stop of the platter, or immediate stop with a tiny final move backwards).  Not a dig deal i guess.

I have that huge service manual and to my surprise TT-101 motor does not require lubrication ! 

I know that TT-101 can be calibrated according to the service manual. 

 Platter continuing to rotate after you press the stop button is associated with calibration. A well calibrated turntable should stop pretty much dead when you press the stop button. But my TT101, which was calibrated by JP and works wonderfully, also moves an inch or two more after I press the stop button with an LP on the platter and a heavier than normal turntable mat (SAEC SS300) . I decided not to worry about this, because of the extra mass. If JP is anywhere around, perhaps he will comment.

@chakster 

I have that huge service manual and to my surprise TT-101 motor does not require lubrication !

 If anyone believes that "I have a bridge" and all that.