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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
lewm
13,293 posts
 
Just a note from the peanut gallery:
Halcro, you and Richard are actually in agreement. The statement from Feickert (or whatever was the outside source) was that record eccentricity will produce a regular irregularity in the frequency, forming a sine wave around the center frequency. Since one is interested in wow and flutter due only to tt platter speed variations, that sine wave must be filtered out or subtracted from whatever is the actual wave form. The remainder would constitute w and f due to the tt only. Ideally, that would leave a straight line, if wow and flutter due to the tt were zero. I think we can all agree on that, including you and Richard.
dover
2,262 posts
 
Lewm -
No they are not in agreement. Halcro does not accept that the deviations in the sine wave are wow and flutter ( as explained by Feickert ). Richardkrebs argued that the spikes were speed corrections generated by the TT error correction, but they could be caused by many things, all we know is that they are speed deviations.

Other than eccentricity wow and flutter can be caused by imperfections in the record surface ( you must have heard of warp wow ) and tonearm/cartridge issues. So your statement that "The remainder would constitute w and f due to the tt only" is not correct.
lewm
13,293 posts
 
Dover, No one can be absolutely correct, except you. I should have remembered that from past experience. Not that I would argue with your obvious point here, your condescending attitude notwithstanding. Instead of "due to the tt only", I obviously should have written "due to factors other than LP eccentricity" or words to that effect. The point was subtracting out the sinusiodal noise due to LP eccentricity. Serenity now!
halcro's avatar
halcro OP
2,664 posts
 
Dover has comprehension problems (as well as others) with both my statements and those of Markus who designed the Feickert software.
The spikes in the generated sinewave are NOT "speed corrections generated by turntable error correction".
They are simply part of the software program to compensate for non-centricity of the test record and the effect it has on the steady-state 3150Hz test tone.
The previous software plot ( which I included) does not include these spikes.
How anyone can interpret it otherwise is beyond belief. Markus is amused....
Why don't you contact him yourself Dover to explain your interpretations...?
fleib
1,124 posts
 
Halcro,
I don't know what test record you're using, but this software, app, or whatever, is giving an erroneous impression. The TT101 has W/F 0.02% WRMS, and speed deviation of zero w/up to 120g VTF.

That W/F is at the limit of conventional testing ability. With a DIN 45 465 test disc w/locked groove and centering, you can test to 0.06% unweighted wow, if you have the program.

Below is a link to Kevin (KAB) talking about positional updating tables vs. linear frequency generators. It's not what we're discussing, but might give some perspective:
http://www.kabusa.com/myth2.htm

Regards,
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