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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.
halcro
fleib
1,124 posts
 

Halcro, I wasn't sure exactly what I am doing with the TT81. I can get an old Victor plinth relatively cheap, but I've decided to copy your design, with changes of course. 

Other things have come up and it hasn't been to the tech yet, but it runs and I have a 100V converter.  I'm thinking of making a pod out of Kenwood style composite - ground limestone with polyester resin. 

There's a ground screw on the bottom of the metal cage. I read somewhere that's it's necessary to use it. Any comment?

Sorry my response took so long.

Regards,

lewm
13,722 posts
 
Fleib, While you are thinking of copying the material used by Kenwood, note also that they never used an outboard pod; their engineers saw the value in firmly coupling the tonearm mount to the tt bearing assembly and motor.  Mimicking their approach with your TT81 chassis is going to be difficult, but you could at least approximate it.
fleib
1,124 posts
 

Lew, I think that would be near impossible and might be better without the coupling. Isolating the motor unit from the arm would eliminate vibrations shared one to the other. On the other hand, outside energy hitting the platter or plinth would be different from that hitting the arm (board).  There would be similarities, but I'm not sure if shared vibrations is a positive thing. Would micro detail increase or decrease?

In this case I see the value in the Halcro approach. I think it might be better, if executed well. Looking at the stock Victor plinth it seems like just a plywood laminate with a hole in the middle with 2 wood armboards. I think I can make a better plinth, but not sure I want to.

Regards,

lewm
13,722 posts
 
Fleib, The debate between Halcro and I was never ending and fruitless, so I abandoned it, probably to the relief of several.  I would submit that you WANT the tonearm and bearing to be equally affected by outside disturbances of all kinds, so as to perturb the one with respect to the other as little as possible whilst the stylus, which is physically at one with the pivot of the tonearm does its business of tracing the groove, which is physically at one with the platter and bearing.  That's my story, and I am sticking to it, along with a myriad of professionals in the business of designing, building, and selling turntables.

My thought experiment, which was mocked at the time by Halcro, is to imagine that you have to perform a delicate operation in a rowboat that is floating in the sea.  Would it be easier to work accurately, if you have your project in the boat with you, such that the rocking of the boat will affect both you and your project equally and simultaneously, or in another boat floating independently beside you?

halcro's avatar
halcro OP
2,664 posts
 
The interesting thing about this new technics turntable is that Jonathan Carr appears to be involved or in some way supporting it.....
http://www.analogplanet.com/content/new-technics-sl-1200gae-not-your-fathers-old-technics-sl-1200mk2...
I can't recall him ever expressing a liking for DD technology on these Forums?
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