Good point, Ralph. Also, if you use this un-named but "very heavy" pad (I assume you mean "mat") on an SP10 or the like, it may have a negative effect on the performance of the drive system, since the servo mechanism was designed specifically for the mass of the stock SP10 platter + mat. Whereas the same mat might have a less deleterious effect on the performance of your Empire. |
Jb0194, The fact that your turntable still runs at the correct average speed after you added all that mass, especially a heavy periphery ring, is not proof that there is no deleterious effect. But I don't think the Dual has a servo mechanism at all to worry about, and I believe it's an idler type in the first place, not a DD. You would of course know better than I about that. My remark was strictly with regard to servo-controlled DD tables. Moreover, if it sounds better to you with the added gadgets, that's the bottom line. |
Thanks, Mark. That's a lot more information than I can glean from the Denon literature from that era. And the schematic is beyond my comprehension. Others, including Technics as you note, have spoken of the Technics SP10 motor as being of the DC type. Now I see that this is a distinction without a major difference. |
Dear Ralph, I would have to agree with Axel. Platter mats (pads) have received LOTS of attention during the vinyl renaissance, both in the aftermarket and from turntable manufacturers. Just do a search of any website that features products for vinyl reproduction, and you will find dozens of candidates. In fact, there are too many different choices for any one person to evaluate. Materials include felt, rubber (or some variant thereof), sorbothane, carbon fiber, graphite, copper, other metal types, dots (made of cork, felt, what have you), and combinations of any of the foregoing, plus no mat at all. I guess what you are saying is that only the one mat made in small numbers and sold only in Minneapolis area and on early SOTA tables is really proper. Can you reveal what it is made of? By the way, many would agree with you that the mat should take energy away from the LP and therefore should be made from a material that is similar to vinyl. So why not vinyl? |
Mark, Just out of curiosity, do you know anything about the build of the motor in a Denon DP80, iron core or coreless? I do know that it is a 3-phase synchronous AC motor the speed of which is controlled via the servo by varying the frequency of the AC. This is different from the SP10, but I had not thought about whether the DP80 motor had an iron core or not. Indeed, I did not appreciate the significance of that fact until Hiho and you had the exchange above. I ask because the DP80 gives me the very same "smooth" feeling that Hiho experiences with his Pioneer. In a heavy slate plinth, the Denon is rather addictive.
Raul and Ralph, I hope some time it will be possible for you to reveal the nature of these especially good tt mats. It would be fascinating to find out whether both mats were made of similar materials. |
Nilthepill, To answer your question with my opinion, no. I don't see how a magnetic bearing, which acts in the vertical plane only, can possibly have such a dramatic effect on the drive system, which is mostly operating in the horizontal plane. But your question assumes that low mass/direct drive is inherently superior to belt drive/high mass, which probably is not categorically true. Success of either design philosophy will have a lot to do with execution. I am thinking that, while I personally have begun to favor the low mass platter/direct- or idler- drive turntables based on my listening, this approach is the most difficult and potentially expensive to perfect. Whereas I think it is easier to get "decent" results with a high mass platter/weak motor/low compliance belt. Maybe that explains the predominance of the latter type of turntable in the "high end". I'd love to hear a Grand Prix Monaco myself. I wonder whether the carbon fiber adds a coloration, for one thing. |
Nilthepill, I guess I don't understand the concept of the CMB. I made certain assumptions that must be off base. I've actually never seen any Clearaudio turntable, except perhaps their low end ones, in the flesh. But then, I lead a sheltered life here in the Washington DC area, where the hi-end audio emporium is as rare as a dinosaur. |
Axel, This is like the eddy current brake on a Garrard. Mark Kelly has written much on this subject. I now get what you and Nilthepill are talking about; the repelling magnets not only provide a force in the vertical plane but also they resist rotation in the horizontal plane due to the eddy current effect. Cool. I neglected that factor in my earlier post. |
Mark, Thank you for putting us back on the right track, as you always do. I had read somewhere else that the Verdier develops an eddy current effect by virtue of its apposed magnets, so I assumed that the same might be true of the Clearaudio. Are your remarks re the effect of bearing friction in agreement with Win's description of the virtues of the Verdier? |
As one who has just wasted the better part of a beautiful hot Sunday afternoon trying to assemble my Lenco in its slate plinth, only to fatally smudge the professional paint job on the PTP3 (it will need to be redone) and find that I had ordered the wrong very fancy push-button switch, I am in no position to take issue with anyone else's feaux pas. Who knew that "off-(on)" in the Mouser catalogue is not the same as "off-on"? I now know. This is not really OT because I am talking about assembling an idler drive tt. |
Thanks, guys, for putting me on the right track as to the theory of the Verdier and the harsh reality of pushbutton switches. Sadly, I now see that pushbutton switches of the "push-on/push-off" variety are rare indeed, and I need to find one to fit the 5/8" hole that I already drilled to accommodate it. As Win and I discussed, the switch I did buy will work fine, IF I want to stand by the turntable with my finger on it whilst I listen to music. It does, however, fit the hole I drilled. Live and learn. |
Axel, You mean the "momentary" switch like the one I tried to use can also be used with a relay? That's an interesting point. There's no place to hide the relay in a solid slate plinth, but perhaps a small one mounted underneath would be unobtrusive enough to get by.
Ralph, those guitar switches are pretty big, are they not? Has to fit a 5/8'-diameter hole, but I will look at your referenced site.
Dave, I think I looked at the Allied catalog at about 2 AM last night. In my groggy state, I may have missed something. I did find a near-to-correct size switch made by APEM, sold by Digikey. I think I can fudge it with some washers.
Sorry, this is so-o-o-o off-topic. But it is my very preliminary observation that a massive plinth (layered wood or slate) makes good direct-drive and idler-drive turntables sound not only better but more alike than different from each other. I am pursuing this comparison further. It keeps me off the street, most of the time. |
Ralph, I agree completely with what you say re the effect of plinth-ing. I was surprised that the slate plinth had such a profound effect on the "sound" of my Denon DP80. I would have thought that a direct-drive system would be rather a closed one in which colorations introduced by the drive were directly "injected" (for want of a better term) into the audio signal via the coupling of motor to spindle. Thus, except for better controlling the inertia of the motor itself, I thought that the positive effect of the slate would be limited. I was quite wrong.
"bass will have more impact, overall greater dynamic impact (more lively, without added brightness), blacker backgrounds..." That's what I hear too. Win's turntable (the Saskia) must be quite awesome. |
Thanks for the help, Mark. I actually found a plain old push-push switch that will likely do the job, but the relay is my next option. This is just to switch a Lenco motor on and off, so sophistication is not a priority. |
