The SZ-1 motor has a built-in flywheel (which helps to make the motor box 6kg heavier than the SX8k2 motor unit) which also has an air bearing, and the floating flywheel is supposed to make the drive even smoother. The flywheel, will of course, raise the overall moment of inertia a bit as well (though not by a lot).
note: I am not sure where the VK gets their moment of inertia number. 26 tons/cm2 is way too high. Given the size/weight of the platter, you'd be physically limited to about 4t/cm2 - which is still pretty good (the biggest direct drive tables were less than half that, but they had torque going for them too). |
Thanks Raul. I remember that number now (which I bet is for platter only; the motor flywheel would add another 8-10% to that number for the SZ-1). I think the Verdier and the highest-end Final Audio tables may have a higher moment of inertia (as would the table that Dertonarm put together a while ago) because of slightly massier platters, but it wouldn't be too much bigger (in the case of the Verdier at least) and I could probably suffer through ownership of the SZ-1...
Wonder why more people don't build dual-voltage motors (one high-voltage motor rim drive motor for start-up and another for maintaining speed on a belt drive). If you did that, you could run a VERY big flywheel and use the outside of your flywheel as your belt pulley, which would mean that you'd largely eliminate the belt tension issue (which Mark Kelly has written about). And this, in turn, makes me think back to the big thread about massy platters, belt drive vs DD, and alternate drive mechanisms that got reasonably technical. |
Mark, Thanks for posting. I had not seen your first post when I wrote and i had not looked at the VK page linked. I was noting the mass moment of inertia of a solid with zero angular velocity (which is the way all Japanese TT specs historically have shown their mass moment of inertia spec - which if I'm reading your idea correctly, reconciles with your recalc above because the coefficient of the square of the gearing is... 1. When I think about it, when my Exclusive P3's capacitors went, it was probably going something like 750rpm too (until I shut it down). If I could harness that and use the spindle, I could have gotten something like 1000 tons/cm^2 (a lot more weight and much bigger r^2). I will go away and digest some of this. As to the Saskia, I had previously read the 'effective mass of 200lbs' bit on the OMA homepage, but as there is no other information, and I have not seen any other info on the table elsewhere, it is difficult for those of us less in the know to understand how that comes about. I will assume (and we all know what people say about that), that the tightly controlled external rotor motor when combined with the turntable's heavy platter results in an effective mass of well over two hundred pounds means that "because it is rim drive not belt drive, when combined with a platter of X mass, we get effective mass of X+Y mass." There is so little information on the OMA page that anyone with a modicum of info could probably see where I am wrong on this too, but I couldn't quickly find any info months ago when I first looked. |
Mark, I understand the calculation but do not understand (from reading the webpage) where the 'gearing coefficient' comes from - higher speed flywheel providing gearing vs 33.3? rim-weighted platter increasing effective rotational inertia when compared to solid mass? |
Thuchan, there is a standalone Micro Seiki product called the HS-80, which was a high-speed inertia unit (made to be added to the 1500/5000/8000 series models). It would probably give much the same effect to the SX-8000 as the motor on the SZ-1 accomplishes. When they come up in the market, they are seriously expensive, but they are probably easier to find than an SZ-1. You can see a picture here (about halfway down the page). |
The last few I have seen go through the internet auctions in Japan have been in the area of JPY 150-175,000 (call it US$1500-1750). I would say they come up about 3-6 times a year. |
Most of the 5000s which are extant are the RX-5000. The "RX-" designation is a solid bearing. There exist some SX-5000s as well. The "SX-" prefix denotes an air bearing turntable. The SX-8000 and the SX-8000 II are roughly similar, but the SX-8000 II is physically more 'integrated', and it usually comes with a vacuum hold-down platter. The SX-8000 tends to go for less than the SX-8000 II but I have not seen an SX-8000 II for sale for many moons (last one I saw went for something like $15-16k if I remember correctly). The SX-8000s I have seen recently (last 18mos or so) have gone for $9-15k on Japanese internet auctions, in varying condition. There seem to be a fair number more of them out. I have never seen an SZ-1 for sale, though I imagine if it came out, it would be more than the SX-8000 II.
I have an SX-8000. I have compared it to the best Japanese DDs of the era but not to rim drive tables. I have not heard a table before or since which digs as much info out of the groove as the SX-8000 with a MAX-237 arm (don't have a 282) and a ZYX UNIverse. When perfectly dialed in, it is a very smoooooooth sound. The large DDs (Exclusive P3, Technics SP-10Mk2 & Mk3, and Sony PS-X9) are also quite good, and you 'feel' the drive which you don't get with the Micro, but the Micro is soooo quiet. |
Syntax, thanks for pointing out the 'local' photos. Should have remembered that system.
Lewm, the photos appear to be the reviews of items which different people have brought into the system. The top photo is a set of Ale Acoustic compression supertweeters. About a quarter of the way down there are some Goto supertweeters. I didn't see any other Goto stuff (the super big horns near the bottom are DIY efforts, as are a bunch of the brass supertweeters). |
Thuchan, I'm still thinking about it, but I think Quiddity's earlier point was that the high speed of the flywheel in the SZ-1 motor (and therefore, probably similarly, the HS-80) offers more theoretical inertia than a (second) heavy platter does if the second heavy platter is spinning at 33.3rpm. I cannot deny that the second SX 8000 would be able to mount 4 tonearms, but then again, so could an SX1500, SX5000, or SX8000 without the "II." I don't know where the 30% number comes from or how one would calculate it. Personally, I've never been able to compare a table to another and come up with a 'percentage improvement'. Best of luck in your quest. |
FM_login,
I am not sure I understand the "non-morphemic tone of Asian language" bit, and I am certainly unaware of how such might relate to "Japanese sound". Japanese language is structurally morphemic, and is not tonal in the way that Asian languages are generally labelled tonal. If "tone" refers to intonation, Japanese is not structurally dissimilar from American English - the intonation is different but the structure of intonation patterns is not.
I think talking about the shape of physique is cute but almost meaningless; in terms of physique the more important aspect might be seating height, as affected by ratio of upper body height vs lower body height combined with average height - the average ear-tuchus span as I think it is technically called :^)...
As for what the Japanese sound is.... some of the favorite tables out there are Linns. For those who play with heavy platter Micros, the most popular arm/cart combos seem to be SME long arms with SPU carts attached. And usually all this is played through a class A amp, in many cases SET.... is that "Japanese sound?"
MUCH more important would be average difference of listening room environment. |
FM_login, I did look at the playback installations of some of you and I kind of confused what the hell you do in audio. Some of you have 5-6 turntables with 10-15 tonearms, which is a strong induction in my mind that a person can be disqualified to make comment about sound. After all audio is not about accumulation and cataloging the differences... Not all of us are blessed with the absolute knowledge of what we like best (and the absolute knowledge that it is indeed, the best) when let loose from the womb. Some of us have to experiment to find out what we like. That said, learning about what else is out there is itself a learning experience about music reproduction. I have acquired a bunch of tables (and a lot more vinyl) because I am learning what I like by listening, not by reading what a self-declared expert tells me I should like. I have started getting rid of tables, and will continue to do so because I have reached a certain set of conclusions. As to TT tweaking and isolation platforms... In my case, I live in a city in an earthquake-prone zone. There are trucks and cars rolling past my building constantly. The difference between my SX-8000 (or my other non-suspended/non-isolated tables) on an air/magnetic-bearing isolation platform and the table on its own is night-and-day obvious. Despite your suggestion that the SX-8000 does not need isolation, I will go with what my ears in my environment tells me is right (rather than trying to dampen the tectonic plates, the rumbling of magma deep under Mt Fuji, or decouple my apt. building from its foundations). As it happens, I also work on other parts of my system (and I imagine others do too) but I don't feel the need to post that on threads about Micro Seikis. I am obviously ill-informed because I don't your site or system. I am, however, curious as to why you would have a "daily driver" cartridge which different (and probably lesser) than your "reference" cartridge. If it was really worth listening to your reference cartridge on all kinds of music, would you not use it on a daily basis? I listen to the carts I want to use on the music I want to listen to. That's my reference. Nilthepill, I agree that is indeed a stroke of luck when the system clicks. I have found a few table/arm/cart combos where it just clicks, but I am also inclined to say that "it just clicks" is also largely a state of mind. |
