Vintage DD turntables. Are we living dangerously?


I have just acquired a 32 year old JVC/Victor TT-101 DD turntable after having its lesser brother, the TT-81 for the last year.
TT-101
This is one of the great DD designs made at a time when the giant Japanese electronics companies like Technics, Denon, JVC/Victor and Pioneer could pour millions of dollars into 'flagship' models to 'enhance' their lower range models which often sold in the millions.
Because of their complexity however.......if they malfunction.....parts are 'unobtanium'....and they often cannot be repaired.
128x128halcro

Dover,

Modern physics says centrifugal force is a misnomer.  It's called
centripetal force.

The Victor motor units are relatively heavy containing the transformer and all the electronics.  One can spin the platter under power and it doesn't go anywhere.  I haven't listened to the table (TT81) under these conditions.

Regards,

Halcro,

I wonder if you would hear a difference if the motor unit was bolted on. I'm sure you're aware of the three bolt holes underneath the edge of the platter. This is how the motors were bolted to the CL-P2D plinth. 

It might be better with the rubber acting as a damper.  Of course you could always use rubber washers in-between.  If the washers were compressed there should be no movement?

With a wooden plinth it's easy to install threaded inserts, but with a stone pod you'd probably have to drill a big enough hole and fill around the insert with epoxy? 

Regards,

Hi Halcro,

I should begin by saying, “nice job on the granite plinth”, which I neglected to mention on my earlier post. The black granite matches the armpods beautifully.

Thank you for the in-depth explanation to my inquiries.  The reason for my curiosity is because I’ve recently joined an exclusive” Are we living dangerously?” club. My JVC/Victor TT-101 was sold to me with a CL-P2 plinth and acrylic dust cover.  The Victor CL-P2 plinth is made from particle board with a veneer clad, faux Rosewood, as with most plinths made from this era. The plinth itself is quite heavy and comes with four large plastic footers.  The TT motor is evenly secured with hardware to the wood plinth.  I’m looking for ways to improve on this plinth; whether it is a custom plinth as you have done or tweak the existing CL-P2.  An Elgar 6000A line conditioner is used to feed 100VAC to the TT-101. I’ve dialed down the Elgar to the lowest possible voltage of 105VAC to best meet TT-101 requirements. I need to shuffle my equipment around to accommodate the TT-101 before spinning any vinyl on this TT.

Since my inquiry on how your custom granite plinth is coupled to the TT-101 motor, several posters have commented to your approach.  To me, it seems intuitive to mechanically fasten the motor to the plinth for best sonic results. What was the rationale to have the motor “sit” on the rubber points rather than have it bolted in place? I noticed the metal skeleton plinth also used rubber supports.  Did you experiment both ways before concluding that this was sonically the best approach? It seems intrinsic that the plinth material selected has a lesser degree of importance when the motor just “sit” on the plinth as opposed to mechanically coupling the motor to the plinth.    

Furthermore, is it possible the granite plinth sounds better than the open metal skeleton design because the granite design encases the TT and is able to shield air borne vibrations reaching the motor?


Regards,

Norm 



halcro
it would be better to mechanically connect it but at this stage, I don't know how?
🤔
Pretty much as fleib mentioned, the way to go and its not that difficult
would be to start by getting 3 threaded inserts, 1 diamond bit [hollow core] that is slightly larger than the insert od drill at low speed with water lubrication. Partially fill the hole with an epoxy, tape over the bottom of the insert to prevent epoxy filling the insert. Place the 3 fasteners
in the rim of of the TT, lower the table and start the fasteners into the threaded inserts while the epoxy is still setting up there by centering
the inserts to the fasteners.
Use a slow setting epoxy to give yourself more time, and have an extra set of hands, one to lower the TT into position but not all the way down, and another to start the aligning threading operation.
Fleib,
Centripetal comes from the latin words "centrum" - centre and "petere" which means to seek. I can assure you that when using centrifuges the contents do indeed fly away from the centre, not towards.
If you have any doubt, at the next carnival you can attend, take a ride on a horizontal spinning wheel and leave your seatbelt off.  Then you can report back to us whether you flew back towards the centre or indeed away from the centre.