I am currently producing 5 new bearing assemblies for retrofitting into the SL 1200. The spindle bearing shaft is 12mm diameter and precision ground from a solid bar nitrided and carbide coated steel. The taper is an integral part of the main shaft (all one piece). The thrust bearing is a ceramic ball supported by a PTFE pad and running in an enclosed oil bath. The housing is machined from solid brass and designed to directly replace the existing unit. The bearing bush is high grade cintered phosphore bronze honed to a clearance of 0.00025inch. The standard bearing is not a particularly close fit and is built for ease of production. This new bearing would be an excellent addition to those considering the 2Kg copper mat.
My question is this: are there any people interested in this vast improvement to the SL1200.?? or am I being over enthusiastic. I estimate that the cost would be about $350 the unit is made in Sydney Australia. If you are interested email me at mhnew@bigpond.net .au I am not using this forum as free advertising but am trying to gauge whether there is sufficient interest for me to have this bearing manufactured on a comercial scale at which time I will place ADDs in the apropiate magazines.
My question is this: are there any people interested in this vast improvement to the SL1200.?? or am I being over enthusiastic. I estimate that the cost would be about $350 the unit is made in Sydney Australia. If you are interested email me at mhnew@bigpond.net .au I am not using this forum as free advertising but am trying to gauge whether there is sufficient interest for me to have this bearing manufactured on a comercial scale at which time I will place ADDs in the apropiate magazines.
Are we talking about the Technics SL1200? or is there some other SL1200 as well?
Around here, SL1200 tables are a common choice for DJ use. I see them in for repair all the time, but the repair is almost always just a new signal cable.
Once in a while I get a power switch assembly that falls apart. Rarer still is an actual electronic problem in the platter drive circuits.
These units get used HARD, and they get packed into road cases and moved every night. But in all that time I have never seen one with a troubled spindle bearing.
I take nothing away from your efforts, but what problem does it solve? IS there some hifi application for these tables and you are reducing rumble or flutter or something? These tables are pretty sturdy, and I think of them as working-units. (as opposed to polite home use units) I don;t really think of them as high-end in any way. Who would be your customer and why?
But I am in pro audio, not hifi. Forgive me if i am ignorant of your market.
Around here, SL1200 tables are a common choice for DJ use. I see them in for repair all the time, but the repair is almost always just a new signal cable.
Once in a while I get a power switch assembly that falls apart. Rarer still is an actual electronic problem in the platter drive circuits.
These units get used HARD, and they get packed into road cases and moved every night. But in all that time I have never seen one with a troubled spindle bearing.
I take nothing away from your efforts, but what problem does it solve? IS there some hifi application for these tables and you are reducing rumble or flutter or something? These tables are pretty sturdy, and I think of them as working-units. (as opposed to polite home use units) I don;t really think of them as high-end in any way. Who would be your customer and why?
But I am in pro audio, not hifi. Forgive me if i am ignorant of your market.
Thanks for your opinions Enzo, You are absolutely correct the SL1200 is the first choice for DJs. However there has of recent times been something of a large embrace of the 1200 as a worthy HiFi turntable by those enthusisats in the UK and here and also in the US judging from some of the forums I have followed.
The reasoning being that a good quality direct drive unit will win most times over an elastic band driven units!!! for bass reproduction. Indeed there is a company in the US or maybe it's Canada that manufactures an external power supply for the 1200 ( it removes all mains interferance from the chassis) I have one and it does indeed make a difference! although I have connected it differently.
It is for this reason that I investigated the bearing assembly and reasoned that it could be improved considerably for high quality reproduction, I am not talking DJ requirements here. In fact fitted with a decent tone arm with MC and copper mat together with the afore mentioned power upgrade the unit transforms to a quality audio turntable.
The reasoning being that a good quality direct drive unit will win most times over an elastic band driven units!!! for bass reproduction. Indeed there is a company in the US or maybe it's Canada that manufactures an external power supply for the 1200 ( it removes all mains interferance from the chassis) I have one and it does indeed make a difference! although I have connected it differently.
It is for this reason that I investigated the bearing assembly and reasoned that it could be improved considerably for high quality reproduction, I am not talking DJ requirements here. In fact fitted with a decent tone arm with MC and copper mat together with the afore mentioned power upgrade the unit transforms to a quality audio turntable.
technics Sl-1200 bearing
Hi Stoolpigion!
No, the bearing is not part of the motor, although it obviously is tightly integrated with it. The bearing is a free standing assembly which bolts onto the main chassis with three long bolts together with the drive board which has to accurately register centrally with the bearing as it carries the motor coil assembly. The locating taper for the platter is in fact a separate piece of brass pushed onto the polished steel spindle and located by a "C" clip. The thrust is taken by a very small piece of ceramic embedded into the bottom retaining plate which I have noticed wears quickly.
Hi Stoolpigion!
No, the bearing is not part of the motor, although it obviously is tightly integrated with it. The bearing is a free standing assembly which bolts onto the main chassis with three long bolts together with the drive board which has to accurately register centrally with the bearing as it carries the motor coil assembly. The locating taper for the platter is in fact a separate piece of brass pushed onto the polished steel spindle and located by a "C" clip. The thrust is taken by a very small piece of ceramic embedded into the bottom retaining plate which I have noticed wears quickly.
I am a fan of direct drive turntables. I do think the SL-1200mk2 is a great table not just for DJ but also for hi fi. One thing I do wish is there is an after market product to improve the light platter. Machining a new platter would be great but not cost efficient but I do see the possibility for a metal mat to give it heft to help damping vibration.
But what's on my wish list is an adapter plate to place on top of the stock platter and have a cylindrical rim so I can use it tape drive another platter. That way, I can use it as a turntable motor to tape drive another turntable and at the same time use it as a direct drive turntable - best of both world! The high torque and stable speed of the SL-1200mk2 is an excellent turntable motor. I think Teres turntable owners will benefit greatly from this. The problem is that the platter on the SL-1200 is beveled that you cannot wrap a tape or belt around it. This has been very frustrating for me. I got around it by using a platter from another direct-drive upside down on top of the SL-1200 platter to act as a pulley. If there's an adapter plate like that, it would be heaven. Exact size is not that important as long as it's in the 12" ballpark and the exact speed can be adjusted by the pitch control. Any possibility of such product?
I, however, don't see the need for a new bearing or a product as such. Maybe a new thrust plate at the bottom of the bearing and a thicker supporting plate below the thrust plate to make it more stable and less flexing.
But what's on my wish list is an adapter plate to place on top of the stock platter and have a cylindrical rim so I can use it tape drive another platter. That way, I can use it as a turntable motor to tape drive another turntable and at the same time use it as a direct drive turntable - best of both world! The high torque and stable speed of the SL-1200mk2 is an excellent turntable motor. I think Teres turntable owners will benefit greatly from this. The problem is that the platter on the SL-1200 is beveled that you cannot wrap a tape or belt around it. This has been very frustrating for me. I got around it by using a platter from another direct-drive upside down on top of the SL-1200 platter to act as a pulley. If there's an adapter plate like that, it would be heaven. Exact size is not that important as long as it's in the 12" ballpark and the exact speed can be adjusted by the pitch control. Any possibility of such product?
I, however, don't see the need for a new bearing or a product as such. Maybe a new thrust plate at the bottom of the bearing and a thicker supporting plate below the thrust plate to make it more stable and less flexing.
Here's an example I am talking about. From a thread a while ago.
http://www.diyaudio.com/forums/attachment.php?s=&postid=1876531&stamp=1247187644
http://www.diyaudio.com/forums/attachment.php?s=&postid=1876531&stamp=1247187644
After rereading your first post again. Yes, I think there is a market for a new bearing of the SL1200. Indeed, the bearing on the Technics can be improved. In fact they use the same bearing on just about EVERY model except the SP10. With a newly improved bearing, the audiophile can improve it on their SP15, SP25, SL300mk2, SL1400mk2, SL1500mk2, SL1600mk2, SL1700mk2, SL1800mk2. They are almost the same thing with different auto functions. The 1300/1400/1500 series have better platters as they are all balanced with drilled holes and they are also thicker. In the States, people haven't caught on to direct drive turntables yet. They are still stuck in the Linn mentality or overly loyal to idler drives. I personally like all genres but direct drive done right to me represents the most elegant solution from a engineering stand point. I am also very fond of coreless motor DD tables that has an extremely smooth sound that's as fluid as a belt drive. And DD bass dynamic is still unmatched. Belt-drive tables with wimpy motors and rubber belts are not my cup of tea - one particular brand with a motor of the tiniest torque almost put me to sleep. I hope your project will bring to fruition. Good luck.
Tehcnics Turntable bearings
Hi, directdriver
Today is Wednesday at 3.20 and would you believe I have just returned home and waiting for me was a 2Kg copper platter machined to my specs, to exaactly fit the 1200 platter (and it's silly rim) the supplier is Larry Denham of LTJ Engineering Newmarket Ontario The company's web site is TTweights.com
5-1111 Gorham St. I have not had time to test the mat as I have currently removed the maine drive board from my own 1200 in order to make sure my new bearing assembly fits accurately
(Could not locate another 1200 in my area at a reasonable price)!!
I believe Larry will now be producing these mats to these dimensions for those who need them. He has undercut the outside diameter so as to fit exactly inside the lip from dimensions we jointly discussed (a lip bottom radius must be allowed for) It is a beautifully machined piece of work executed on a very accurate lathe mounted vacuum jig. I fits my platter perfectly, and I can recomend it.
On the subject of a better bearing for the Audiophile, I have managed to obtained a new bearing assembly which to use as a pattern, however as I had to remove the driver board and coil assembly from my own unit I decided to keep the newly aquired bearing and to use the old one from my 1200 to dismantle.
This is where I got quite a suprise I noticed a wear mark on the spindle and used my 0.001mm swiss micrometer to measure the wear, sure enough approx 0.005mm was detected. On cleaning all risidual oil from the phos bronze bush and reinserting the spindle I could detect at least 1+1/2 thou of movement. So you see there is room for improvement, most certainly if you are going to upgrade to the copper mat. which incidentally also has a relieved centre portion for the label.
Hi, directdriver
Today is Wednesday at 3.20 and would you believe I have just returned home and waiting for me was a 2Kg copper platter machined to my specs, to exaactly fit the 1200 platter (and it's silly rim) the supplier is Larry Denham of LTJ Engineering Newmarket Ontario The company's web site is TTweights.com
5-1111 Gorham St. I have not had time to test the mat as I have currently removed the maine drive board from my own 1200 in order to make sure my new bearing assembly fits accurately
(Could not locate another 1200 in my area at a reasonable price)!!
I believe Larry will now be producing these mats to these dimensions for those who need them. He has undercut the outside diameter so as to fit exactly inside the lip from dimensions we jointly discussed (a lip bottom radius must be allowed for) It is a beautifully machined piece of work executed on a very accurate lathe mounted vacuum jig. I fits my platter perfectly, and I can recomend it.
On the subject of a better bearing for the Audiophile, I have managed to obtained a new bearing assembly which to use as a pattern, however as I had to remove the driver board and coil assembly from my own unit I decided to keep the newly aquired bearing and to use the old one from my 1200 to dismantle.
This is where I got quite a suprise I noticed a wear mark on the spindle and used my 0.001mm swiss micrometer to measure the wear, sure enough approx 0.005mm was detected. On cleaning all risidual oil from the phos bronze bush and reinserting the spindle I could detect at least 1+1/2 thou of movement. So you see there is room for improvement, most certainly if you are going to upgrade to the copper mat. which incidentally also has a relieved centre portion for the label.
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