Vintage DD turntables. Are we living dangerously?

Henry, Thanks for the tip on the clickable links. As for mats, since I have yet no listening experience with the TT101, I cannot comment on its mat. With my Lenco and my SP10 Mk3, I am a big fan of the Boston Audio Mat1 (for the Lenco) and Mat2 (for the Mk3). (Mat2 is thicker and heavier than Mat1.) I've tried several different mats on each, and the BA mats are current winners. I totally agree about the colorations of the OEM rubber mats as heard on my Denon DP80 and on my Technics tt's. They not only color the music, but I think the rubber mats have colored people's opinions about direct-drive "sound". I wanted also to note that Kenwood was ahead of its time in offering its stainless steel platter sheet in lieu of rubber. But so too was Micro Seiki in offering a copper mat (and a gunmetal platter which can be used with no mat), albeit they are not famed as makers of dd turntables. Kenwood made an optional ceramic platter sheet for the L07D. I have only seen photos of that, but the scuttlebutt is to avoid it. I would not feel inclined to mess with the stainless steel platter sheet on the L07D. Currently, my SP10 Mk3 is receiving the Krebs upgrade and so is out of service. I have been listening regularly to the L07D with an Ortofon MC2000 cartridge (Raul's old favorite MC), and the sound is glorious. I cannot fault it.

Thanks for your concern re the TT101 on "Hold". There is no problem in terms of displaying 33.33 or 45.00. It goes right up to display those two speeds and holds those numbers firmly. The problem is that occasionally it will go into its typical failure mode after 3-4 minutes: the tach lights go out, except for the decimal point, and the platter coasts to a stop (no brake effect). It's as if someone pulled the plug, except the power lights are all "on". If you then re-start, it will work fine, as if nothing bad had happened. So far, in the nude, it has been dead nuts reliable when set to "Run" but does crash as described, about one out of 10 times, when the tach is set to Hold.

I agree with Halcro’s assessment of the thin Jico mat. I have about 8 leather mats (some are diy) and I’ve tried many different configurations (stacked in various order), and the thin Jico one comes out on top (so far). The Jico mat extends over the lip of the victor’s platter unlike the OEM pigskin and my 47 Labs deerskin mats. I believe this is important, because I have found that if the outer rim of a record touches the bare alu platter, one can hear a sort of ringing. That was one reason I was stacking mats.

Aigenga: your iec post piqued my interest, but you don't say in what particular way(s) 'life is good' with the new cord. Can you elaborate?

I followed your lead on another matter: swapped out the stock ball bearing with a 4mm SiNi one. Thanks for posting the dimensions on the bearing. I can't say I heard a significant difference, but one visible difference I noted is this: the OEM ball bearing is scarred by 'grooves'--caused by either the bottom of the spindle or by the thrust pad (go here: http://cgim.audiogon.com/i/vs/i/f/1425847335.jpg --for some reason mark up tags are not working)--while the the harder SiNi is not.[n.b.: audiogon's system compresses my pic so the grooves may not be very clear; trust me they're there and are easily visible in the original pic). One would surmise that this increased bearing wear would have sonic consequences over time.

While the bearing swap did not result in anything significant for me, I can report that a change in lubrication did. I had been using Redline 20 wt race oil, as recommended by the Kenwood l-07d guru. Recently, audiogoner Doron suggested I try Royal Purple XPR race oil. I bought the 5w-30. The RP is significantly more viscous than the Redline and this resulted in greatly differing platter stop times (i.e. the time it takes for the platter to reach full stop after pushing the stop button/pulling the plug). With the Redline (at 45rpm), it took 1 minute 10 seconds to stop; with the RP, it took only 43 seconds. One can easily tell the difference between the two oils by how the platter responds to one’s hands. With the RP, the platter feels like it’s running on molasses; the Redline like running ON TOP of water.

Given these observations, and before I gave the RP a listen, I declared victory for the Redline (for surely the higher the degree of freedom of motion the better?). The declaration was premature. The RP yielded a lowered sound floor and a darker background. Evidently, the RP does a better job supporting the ball bearing at its contact point with the plastic thrust pad, thereby lessening (eliminating?) one significant source of noise. One way to confirm this is by adding weight to the platter and seeing whether it affects stop time. Both Doron and I confirmed that adding weight (in my case, I tried a 580g and a 770g weight) does not affect the RP (in both our cases, at 33 rpm the platter stops after 30 sec irrespective of weight). On the other hand, the Redline was down to 50 sec (from 1min) with the 580g weight.

Presumably, at some higher weight, even the RP would be affected. RP sells lighter race oils and I’m tempted to see whether one can achieve both freer motion and superior support.

This then is a consideration for those of you adding significant weight to the tt 101’s platter (perhaps this is part of the reason why the light weight leather mats sound so good?). Of course, whatever benefits accrue from adding really heavy mats and rrecord weights may mitigate the effects of increased bearing noise, so YMMV. And for those who have not changed out the oil on your 30+ year old tables, I’d strongly recommend you consider it (despite Victor’s assertion that the oil never needs changing). It’s so easy to do that even I can do it ☺.

Just be sure that the OEM thrust pad is suited to the silicon nitride ball. Bearing technology is complex.

Did you measure a "lowered sound floor", or is that a subjective judgement based on listening to LPs? These racing motor oils are designed to be used in engines turning several thousand RPM. I am surprised that one good oil would be noticeably superior to another good oil in a tt turning at most 45rpm. But on the other hand, Howard Stearn (L07D guru and surgeon, not the radio shock jock) swears by the Redline for the L07D, and nothing else, as you mentioned. So I guess I should not be surprised that for another table with a different bearing material a different (brand or viscosity?) motor oil might work better. My guess is a 5W-30 Redline would probably perform like the 5W-30 RP.

How do you access the bearing in your TT101? I can envision doing it either from above or below. Once you do that, have you had issues with the platter height? (I think you earlier reported that you did.) Thanks.

Thanks to Henry pointing out the clickable links, I was able to see the photos of the Jico mats. I definitely do not like the fact that the mat hangs over the edges of the platter. Most all LPs have a "lip" around their circumference. Optimally this lip should hang out in space over the edges of the circumference of the platter or platter mat, so the playing surface can be in contact with the platter or platter mat. Having this lip on the LP in contact with the mat would tend to lift the whole playing surface of the LP by a fraction of a millimeter or so off the mat. Just my opinion, but I do not care for that characteristic. I would try to trim the mat so to avoid that issue.

Did you measure a "lowered sound floor", or is that a subjective judgement based on listening to LPs?

The latter, Lewm. It was the proverbial, "I could hear things (on very familiar records) I never heard before" bit. I did buy a mechanic's stethoscope. I placed the probe on the spindle shaft and the bottom of the motor: I didn't hear anything. Suspecting that the scope is not sensitive enough, I put it on a DD table I use to clean records: a hum could easily be heard. Of course, this does not get me very far, since I didn't probe the old bearing or the redline.

Your suspicions re a heavier weight Redline oil are duly noted. I might test that out in the near future, either a heavier weight Redline or a lighter weight RP.

The bearing is accessed from below; you'll need to flip your table upside down. Then unscrew the giant brass screw; it may be secured with some kind of cement that you'll need to remove first.

Your problem with your tt 101 is puzzling. I recall you saying that you could hear your platter scraping. Did you fix that? There are two ways to adjust platter height: the bearing screw at the bottom of the table or shims between the motor and the chassis (there should be 2 of them on each of the 3 screws that secure the motor. Note that with the screw, there is a range that yields the correct motor height(s). Outside that range, one gets one of three things: scraping platter, errant rotation, or complete locking. The easiest way I've found to find the right height is to take black bottom cover off and place your table inbetween two suitably spaced endtables. This way you can access the screw from below while the table is running. Just make small turns to the screw (clockwise--as seen from below--to raise platter). I know you have a stethoscope: use it to hear whether the platter is scraping.