Dmm metal disks?

[Tunes]

I know this is a very noobish question, but where would I be able to acquire metal disks for dmm cutting with a Neumann lathe? Also, while Im at it, where could I get vinyl blanks for using a vinyl cutting lathe? I usually use what ever studio I am working for's disks but I am going to start cutting on my own.

[petermontg]

Have you a VMS82 for DMM?

http://www.apollomasters.com/products.html

[mossboss]

And why would you or any one would want DMM copper discs
These need to be kept in a refrigerator after they are made
Than only taken out bought up to ambient temperature just prior to being cut
Once they are cut than they must be treated/passivated immediately after they are cut or quite a lot of losses will be the end result
This is also including difficulties in removing the Nickel negative plate formed on them as the cut area corrodes quite rapidly unless treated within minutes after the cut
Unless you want to play around with them than fine

Cheers

[sifis1983]

Hi there!

I thought that DMM acts totally opposite

As Wikipedia says:
"there is no need to rush the finalized master disc directly into a refrigerator for groove preservation, as in conventional lacquer disc cutting, before processing the master disc to produce matrices for the pressing of the records."

and:
"The DMM copper master disc can be plated to produce the required number of stampers using the one-step plating process. Rather than having to electroform a master (or "father"), mother and then stampers (the traditional "three-step process"), the DMM copper disc serves as the 'mother". Bypassing the silvering process and two electroforming stages reduces the risk of introducing noise that can be generated in the electroforming (galvanic) process. In cases where hundreds of stampers may be required, the DMM disc is often plated to produce a master and mother, from which many stampers are then made."


So, is this true? Or Mossboss is right?

[opcode66]

Does anyone actually refigerate their master lacqeurs after cutting???

[Nickou]

Yes
when I finich a master , I put it in the fridg
the temp is 12 deg , the fridg I use is for wine ... so the masters are near some very nice bottles of french wine !
My cutting room is actualy in Bacelona , so ... I think it is better to do it
I work also in a cutting room in paris , and we don t do it : the temperature in the studio is never high , so ...

when I was working at the plating departement of DFI , the first thing we did was putting the laquers in a fridg during one day , the temp of this fridg was around 5 deg

[mossboss]

Lacquers
Anything up to 8 dB loss can be occur on lacquers that have been cut and left out of the refrigerator
There is a loss regardless as the material that has not been "cut" but rather pushed wants to go back where it was pushed from
The cooling down slows that effect down quite effectively
This was the primary reason that Neumann rejected half speed cutting for a long time as it accentuates that problem
But thats another story
DMM
Now why is it that people believe Wikipedia's articles verbatim?
It is a great resource but not always accurate
Let me say this much
Neumann always offered the passiviting station with every DMM they ever sold
It is imperative that this is done
There are two steps required
1.Since the plates are kept in a refrigerator so as to stop the copper deposit crystalising making it impossible to cut, before it is cut, it is washed on a rotating spindle with water, methylated spirit as well as a lubricant added
This does three things:
First it cleans as well as lubricates the surface, secondly it brings the temperature of the copper to ambient or around the 20-22 C
Thirdly, it gets rid of any water condensation which will be on the copper plate as it is removed from the refrigerator at say 4 C
The plate is dried by spinning it fairly high speed on the preparation system
2. Passivate the copper immediately after is cut so as to stop any other corrosion, apart from the passivating layer which is a controlled corrosion any way, as well as "fix" the cut
There is no more to be said on the matter really despite what wiki or any other pedia says, this is straight out of Neumann as well as steps and procedures by people who do DMM properly, as it was intended
Cheers

[opcode66]

Hmmm. Interesting. I was never told, nor have I read anything indicating that lacquers should be refrigerated after cutting. I suppose I need to buy a small refrigerator for the cutting room now...

[mossboss]

Here is a link to a file that gives you a pic of the Passivating unit as well as the equipment required for the proper treatment of DMM cuts etc
To big to post here Or I forgot how to He He
Note the comments on the passivating unit
Cheers
https://dl.dropbox.com/u/10635643/Toolex%20Alpha%20Equipment%20for%20DMM%20Copper%20Blank%20Manufacture.rar

[Greg Reierson]

Lacquers
Anything up to 8 dB loss can be occur on lacquers that have been cut and left out of the refrigerator
There is a loss regardless as the material that has not been "cut" but rather pushed wants to go back where it was pushed from
The cooling down slows that effect down quite effectively

Would you say it stabilizes over time? IOW, once chilled after cutting, is it safe to bring it back to room temp after x number of hours? Or will the lacquer always seek its former shape = HF loss?

[Serif]

Mossy, sifis1983, Is it possible that both MossBoss and the great Wiki, on this matter, are not in fact contradicting each other?

MossBoss seems to be saying that the DMM blank is refrigerated _prior_ to cutting (to preclude surface granulation) and then gets passivated right after. Conversely, he is saying that the lacquer is refrigerated _after_ the cut (unless galvanizing is possible same-day?)... The lacquer is really allowed to warm up before cutting. 0/"

The great Wiki is simply saying that, unlike Pyrals, the DMM blank doesn't need to be chilled _after_ the spiral-scrape (does it not mention the pre-chill?). This is how it is looking on this screen. Hope this is the answer to our thread.

Cheers,
Hugh Manoid

[diamone]

All I know is in the four years I interned with Len Horowitz - he always said you're supposed to refrigerate lacquers AFTER cutting - and DMM blanks BEFORE cutting.

But he never did either, because generally within the time frame it would take to cool down and warm back up again - it was at the plater's already.

And the one day that I got to go over to Marcussen Mastering to see their operation - same thing - seemed like as soon as something came off the lathe - it was in a truck on it's way to the plater's.

But I seem to recall they DID keep their DMM blanks in a refrigerator.

[flozki]

we did dmm cuts for about 10 years. and we always hade them in a refrigerator (-20 degree celsius or so)
the blank dmm's.
took them out, cut them and then we passivated with if i remember right kaliumdichromate. which was also used as separation layer for the galvanic stampers.

i never do it with laquers. i think that the humidity in a regular fridge is more harmful for the plating process (if exposed for days or weeks) than temperature of lets say 28-30 degree celsius.
but this maybe a plating expert can answer.
sure laying in the sun is bad as well.

[mossboss]

Humanoid.
You nailed it. Some time back I put up a link on a trial with refrigerated or not on lacquers after a cut, it is here somewhere.
I am sure. I can dig it up and post it again if there is any interest
By the way, keep the lacquers In The fridge at normal food temp but in the box they come in.
A 10% chromic acid solution does the trick for passivating copper. Albumin is also used.
Cheers

[GeorgeZ]

Hi Chris and everybody here,

why nobody mentioned the newer technology for preparing copper plates for DMM? I mean the one without need of refrigerator, where the copper plates can be transported and stored with normal boxes in normal temperature... Is it a top secret knowledge?

The older method is sufficient for a plant with both the in-house plating and cutting departments (like here in GZ) or in above-mentioned places, but most standalone still DMM cutting studios (Abbey Road, The Exchange, some German ones) probably use the second, newer method.

I'm not a plating guy and therefore I don't know more details, like Chris knows for sure

[Greg Reierson]

Humanoid.
You nailed it. Some time back I put up a link on a trial with refrigerated or not on lacquers after a cut, it is here somewhere.
I am sure. I can dig it up and post it again if there is any interest

Please do. Thanks!

[TotalSonic]

I can verify what George Z is saying. Can't remember the exact year - but prior to 2004 - there was a change in plating formulation that we did at Europadisk as well which made the necessity for any refrigeration of the DMM blanks much less - in fact essentially optional.

Best regards,
Steve Berson

[mossboss]

Steve
Who is plating copper masters in California now days or did recently? Any ideas or does any one else know the guy? He goes by the name of Dante
It'll be good to find out
Cheers

[TotalSonic]

Steve
Who is plating copper masters in California now days or did recently? Any ideas or does any one else know the guy? He goes by the name of Dante
It'll be good to find out
Cheers

I believe Dante is the name of a cutting technician for the Scientologists. If we're thinking of the same person then he and another woman from there recently contacted me a few months ago looking for sources for DMM blanks - so I don't think they are plating their own right now. The Scientologists are the only ones set up for DMM in all of the Americas to the best of knowledge and I don't personally know of anyone here plating coppers.

Best regards,
Steve Berson

[mossboss]

Thanks Steve
I suspected as much. There are no independent sources really as each DMM owner makes his own
The VF in Hayes will make blanks to order but at 50 british pounds each seems like a lot of money to me any way.
I heard a rumor that originated from the s/s blank supplier that they did send 1000 units to the USA some time back,
I am not sure if it is just a rumor or fact
It does not matter any way as the general public will never get to hear them or see anything out of this effort which has never stopped fascinating me
Who knows where they are with this fantastic idea as in itself it is a brilliant way in preserving sound for ever?
Thanks again
Cheers