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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
richardkrebs
422 posts
 
Fleib
Many years ago I decided to completely replace the platter on my SP10 MK3
The new one consists of a trilaminate of acrylic on the top 15 mm of lead and then duralium.
The  duralium interfaces with spindle and spigots to the lead and acrylic keeping thinks nicely centered. It also houses the rotor magnet and speed sensor/commutation assembly.
I spent a lot of time before hand experimenting with glues. I settled on an epoxy where I adjusted the ratio of the two parts to create a glue that was around the same hardness as acrylic. The idea being to simulate a laminate where the lead was fused to the acrylic. This rather than introducing a lossy layer of glue between the two materials.

The total weight is around 10kg as per the original. Moment of inertia is slightly higher.

I like the result. That said back then I did not experiment with metal or graphite mats. I now know that a SS mat works extremely well on the SP10

cheers 




fleib
1,124 posts
 

Hi Richardkrebs,

Cool platter.  The speed sensor moves with the platter?  Seems a little strange.

Regards,

richardkrebs
422 posts
 
Fleib
The speed sensor consists two parts..., 
The sensor coils which are stationary and a toothed magnet which is attached to the platter.
Sorry, I wasn't clear in my earlier post.

Cheers 


lewm
13,228 posts
 
Richard, What interests me most is WHY did you decide to make an entirely new platter for the Mk3?  And what are the consequences to how it works associated with incorporating one half of a speed sensor device into the platter?  (What's a "toothed magnet"?  I've never been bitten by a magnet.) Did this entail a basic change in the circuitry?
richardkrebs
422 posts
 

Lew.

There were several reasons for the new platter...

- I had just sold my Goldmund Studio and admired the design of its platter, which is acrylic and lead. Although not the lead plug inserts it used. My design uses a lead disc insert.

- The SP platter audibly rings a little without a mat.

- Cosmetically the SP platter looked weird on my newly build triangular plinth.

- It was a fun challenge making a completely new one.

This was some 25 years ago and I cannot recall the performance differences between the two designs, but I did stay with the new assembly. I still have the original platter and it would be possible to try it again. Have heard the original perform exceptionally well with some of the more exotic mats available.

The magnetic teeth are there on the standard platter, so the electronic architecture is original.  Check out the small diameter central ring on the underside, be careful you don't get bitten.


 


cheers.  

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