How can I tell if my EMT is 927 DST or just 927 ST

[musicomm]

Hi,
I bought EMT 927 several months ago and I finally managed to make it play. I had Hz problem because here the Hz is 60 and my EMT is 50 Hz version.
I solved the problem using Hz converter. The converter output is 100 V and 117 V only and I had to rewire to make the turntable for 100V.
Now it turns with proper speed. The sound is pretty good. Above all things, I could feel the sound played by the turntable was stable and neutral. This was very different feeling from what I had from Thorens 124 or Garrard 301.

Last night, while I was listening to the music, I found the speed is strange and saw the motor was shaking itself from time to time. It wasn't normal minor vibration of the motor which all the big motor has. Usually it turned quitely with small vibration which I think is normal. But it was sudden spasmodic trembling.

I switched off the turn and checked if any thing wrong with power connection but I couldn't find anything strange.

Has anybody experienced this kind problem? I cannot imagine what is going on with this turn If you have any idea, please let me share your knowledge.

Another thing I want to ask.......
Since I got this turntable I read any information which is available on the net and found it might be DST version not usual ST. But I am not sure. Is there specific characteristic from which you can tell what is what?

[J.D.]

What a stunner of a thread, there, Mosin. I've only read thru page one and it's already addictive. Perfect audiophile aspirational reading -- can't think of many of us that wouldn't like to have the problem of the OP there (ie, two 927s to restore).

(Just now wondering if they'll get to that 'greymatter' platter material or whatever it was-- that Schopper used for its aftermarket/ replacement td124 nonmagnetic platter... ) Guess I'll just have to get back to the twenty-two pages remaining so I can find out .... Thanks very much for posting that one.

musicomm: don't be afraid of sending Stefano Pasini a polite email to inquire about the intricacies of the Emt. He's a sure source of good info.
http://www.stefanopasini.it/

Good luck,
JD.

[musicomm]

Thank you guys
I think I am going to contact Stefano and get some opinion.
Analogue is not easy!!

[mosin]

FYI, JD

That 'greymatter' platter material is more than likely austenitic cast iron. It is only slightly magnetic due to the high amount of nickel content. (I reverse engineered it.) There are at least seven different alloys in the austenitic cast iron class, but only one that is suitable for a turntable platter, in my opinion.

More information than you ever want to know, if that wasn't:

The smallest heat of the iron that you can have poured is 800lbs., and it will be priced according to the current selling price of the materials on the commodities exchange. Anything less than 800 lbs. will damage the typical furnace used in today's mini mills. That's a lot of platters!

Right now, nickel is through the roof, so the price of a finished platter is probably a bargain because of the number they most likely have in stock due to the required weight of the pour. Expect the next batch of them to be higher priced, especially if they use an alloy that they tweaked by adding even more nickel or other non-magnetic content.

--- The EMT 927 has a 12.5 lb. cast aluminum platter.

[J.D.]

There goes my plan of casting a cutting-edge austenitic-iron tonearm.

Oh well, another day, another flagship High-end innovation down the drain.

You should have seen the counterweight.

J.

[Blue Angel]

FYI, JD

That 'greymatter' platter material is more than likely austenitic cast iron. It is only slightly magnetic due to the high amount of nickel content. (I reverse engineered it.) There are at least seven different alloys in the austenitic cast iron class, but only one that is suitable for a turntable platter, in my opinion.

More information than you ever want to know, if that wasn't:

The smallest heat of the iron that you can have poured is 800lbs., and it will be priced according to the current selling price of the materials on the commodities exchange. Anything less than 800 lbs. will damage the typical furnace used in today's mini mills. That's a lot of platters!

Right now, nickel is through the roof, so the price of a finished platter is probably a bargain because of the number they most likely have in stock due to the required weight of the pour. Expect the next batch of them to be higher priced, especially if they use an alloy that they tweaked by adding even more nickel or other non-magnetic content.

--- The EMT 927 has a 12.5 lb. cast aluminum platter.

I bought a 12mm thick plate of pure nickel weighing about 6kg 12 years ago and still have it. Maybe I can sell it and go fishing?

ba

[musicomm]

I think my turn is 927D.
There are several things which are different from ST version. Confusing thing is the body is marked as 927ST and all other things which my turn has tells me it is special D version.
First, the plate marked as 927D. (927D is a mono version of 927DST). And. the the mat is glass. And the pole, I don't know how to call it, for LP location in the center of the turntable, has shape of cone and has spring so the LP stops before it touchs the glass mat and you need to puch the LP down to the mat by stabilizer. And the quick start switch is blocked by a piece of steel plate.
I am adding some pictures. Please see those pictures and let me hear your opinion.

Hmm...How do you upload pictures?????

[musicomm]

another pic

[musicomm]

one more pic

[musicomm]

markj on the body

[jloveys]

Hi Kim, you have a very rare 927 D version of the 927st . The "D" means that it has a glass auxiliary platter (Glassmat ) , a special glass-rubber mat that replaced the standard acrylic mat . The "st" means that the power supply is made for the 139 stereo phono equalizer. The lighter acrylic mat ( 927 A ) has a felt brake to allow instant start/stop for broadcast use. With the glass auxiliary platter the clutch system can't be used but it is not a problem in domestic use.
Some 927 users say that the glass mat sounds better, some others say it makes no difference.
EMT 927 restoration is a real dedication and only a few experts have the knowledge and experience to make them work as intended by the factory 40 years ago…so my advice is to contact one of them.
My double 927 restoration project is made by Hans Van Vliet in Holland , you can contact him about your motor trouble, he will tell you the best thing to do.

Jean

[musicomm]

Hi, Jean,Thank you for the answer.
I am learning everyday about the turn, EMT 927. . And I am delight to learn that my turn is one of the rarest.
It is fascinating to study about the legend with the real right next you. Anyway congratulation of your project which is near to completion. Your heart must run very fast these days for the result. And one of the best thing here is to take time and try to complete as perfect as possible.

I asked to my friend who has many German machines (and the platters^^. He said he has an motor too . He has 927, R82,and R37-I haven't seen R37 yet) about my turn problem and his opinion was that the capacitor for the motor start might be the problem. So I am looking for the same or substitute - 3mf Frako . How is your motor anyway? Has the speed steady? Run quitely? Is there any need to change any part from power supply?

How about the tonearm? I am thinking to install re-make 997 because original is not easy to find and quite expensive. I haven't used that but it looked quite good to me and I couldn't tell if that was replica or original. (930 with 997 replica)


Kim

[musicomm]

Hi,
I am thinking to change the cap which is for the motor start, I believe.
It is marked as Frako and 3uf.
I couldn't find the same one yet but found some similiar ones.

For example this one has 5uF instead of 3. Do you think this will work with 927 motor?

http://www.ebay.de/itm/56x-Motor-Konden ... 4178wt_905

And there is another which is made by same company Froko and similiar number to 3uF but used.

http://www.ebay.de/itm/2-x-Kondensatore ... 578wt_1344

Should the cap have the same capacity or will it be ok to use those one?

Kim

[Stefano]

Dear friends,

I answer to this user in the Forum, as he posted this question here before sending me (and others, I guess....) a private mail that is simply a copy-and-paste of this message.

I don't know what has been 'wired' to convert the frequency to use this 927 at home: if it is an 'inverter' , why are the capacitors still there? Anyway changing them is easy, a pack of original replacements are available from the German EMT specialists.

IMHO, I have no certainty that this is a genuine 927D. The centre spindle is not what I had on mine (the original one is quite 'thin', 5 mm to allow for a precise centering of the vynil grooves: see a similar item fitted on a 927F at http://www.stefanopasini.it/EMT_index_927.htm ) and this can be fitted on any 927, as the glass platter. The screwed-on chassis plate means little or nothing to us, as the number of this pre-1961 machine is not listed in today's EMT archives. The only original engraving is '927st'.

Looking at the pics give me some more food for thought. Fitting a non-original tonearm, intead of its original Ortofon (the ONLY tonearm for this series of 927), compromises quite seriously the sound quality of what could be a great turntable. Moreover, using it as it rests on its lower metal 'utility' frame furtherly degrades its sound: the instructions for every idler-wheel EMT recommends suspending it in an appropriate custom-made console, resting on four rubber corners provided under the four corners of the main (grey) chassis. I suspect that this 927st, in the present conditions, sounds more or less like a 938, and surely not better than a good 124.

I would be very curious to see what a R37 is, and there is NO 'R82'....

Kind regards

Stefano