Rule of thumb for 7" masters cutting?

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cymbalism
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Rule of thumb for 7" masters cutting?

Post: # 11490Unread post cymbalism
Sat Nov 20, 2010 10:23 pm

A client of mine has done a few 7"s with me and is going to get their first professional 7" pressed and asked me to cut the masters for them. I'm both honored and shocked really that they asked me but I have not cut a master for plating before.

If I'm correct, the pressing plant needs a 10" master for pressing 7"s as far as I have found reading up on it. When cutting the master do you just start the intro grooves a little ahead of the 7" measurement to allow proper groove start time? I've seen pressed records that start right at the 6 7/8" point and some where the groove is before the start of the vinyl.

Any advise is appreciated. If I can pull this off well I'm going to seriously contemplate the diy press mark is working on and get stampers made for myself

Thanks guys!
all the best!
- tommie 'plan 9' emmi
poly-cut lathe cuts / cymbalism recordings

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mossboss
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Post: # 11492Unread post mossboss
Sun Nov 21, 2010 4:43 am

Ok Tommie
Yes that is correct 10" for 7"s 14" for 12"s
Where you start and finish
Ok here is a link printed out and stick to it you cannot go wrong
Cheers
http://www.aardvarkmastering.com/riaa.htm
Chris

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Aussie0zborn
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Post: # 11493Unread post Aussie0zborn
Sun Nov 21, 2010 4:58 am

Yes, you need to cut a 7" disc on a 10" lacquer. You can use a 12" lacquer or larger but that is just a waste of material and may cost extra in plating so stick with a 10" lacquer.

The size of a 7" record is 6.89 inches so the lead-in groove should start within this diameter rather than cutting outside the 7" mark and then spiralling across. That spiral across the 7" mark can cause the stamper to break. If its a small run its probably not a major issue.

The Neumann VMS70 and VMS80 lathes move the carriage across to the start point and drop the stylus to cut an almost concentric groove being the fist spiral of the lead-in grooves. The Neumann AM32B and the VMS62 dont have this function as standard and so the cut is performed outside the 7" area and you spiral across to the start of the lead-in grooves hence the lead-in grooves starting outside of the record area as you mentioned. I dont know about the Scully lathe.

If you are doing the lead-in groove manually, make sure you allow enough of it as some 7" record profiles are heavily tapered at the edge and if you dont have enough lead-in, the stlylus can slip off the record.

If you get a sample pressing from the plant you will be able to determine how much lead-in groove you should have.

Enjoy and I hope you remember to carve your initials into the dead-wax area!

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jjgolden
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Post: # 11526Unread post jjgolden
Mon Nov 22, 2010 4:19 pm

The RIAA is the reference diameters to use.
You can also put up a 7" pressing on your lathe and scroll the cutter into where the lead in and audio start portion of the disc is. Then mark it somehow (tape/pencil) on your lathe and use it as a reference point for where to drop head and start music. Congrats!

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opcode66
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Post: # 11528Unread post opcode66
Mon Nov 22, 2010 4:37 pm

Aussie0zborn wrote:The Neumann AM32B and the VMS62 dont have this function as standard and so the cut is performed outside the 7" area and you spiral across to the start of the lead-in grooves hence the lead-in grooves starting outside of the record area as you mentioned.
I remember reading and being told that you should never have a lead-in groove start outside of the specified diameters. The reason had to do with the use of a stamper plate made from a master where lead-in groove that starts too far out from the center hole. The stamper plate would degrade quickly around the edge. And, it could potentially damage the press.

Is this wrong? Or is this exaggerated? I was told repeatedly to always use the automatic head drop/lead-in groove cutting on the VMS70 when cutting a master lacquer for exactly this reason.
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cymbalism
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Post: # 11529Unread post cymbalism
Mon Nov 22, 2010 7:13 pm

I'm just gonna play it safe and cut 1/32" in from the edge where the vinyl would start. A lot of records I've purchased lately you can physically see where the lathe dropped the stylus. I never used to notice it until I started cutting but now I see it all the time. I've heard both sides from two people i respect who cut masters and they both commented to start either right at the edge of the 7" or a little in from 7".

Thanks guys! I'll give a full report when they come back from the plant!
all the best!
- tommie 'plan 9' emmi
poly-cut lathe cuts / cymbalism recordings

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mossboss
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Post: # 11535Unread post mossboss
Tue Nov 23, 2010 1:58 am

opcode66 wrote:
Aussie0zborn wrote:The Neumann AM32B and the VMS62 dont have this function as standard and so the cut is performed outside the 7" area and you spiral across to the start of the lead-in grooves hence the lead-in grooves starting outside of the record area as you mentioned.
I remember reading and being told that you should never have a lead-in groove start outside of the specified diameters. The reason had to do with the use of a stamper plate made from a master where lead-in groove that starts too far out from the center hole. The stamper plate would degrade quickly around the edge. And, it could potentially damage the press.

Is this wrong? Or is this exaggerated? I was told repeatedly to always use the automatic head drop/lead-in groove cutting on the VMS70 when cutting a master lacquer for exactly this reason.
Hey Op
It goes something like this
One can Start the groove on the outside press fast on the VMS which will cut a spiral from where you drop the head all the way to where you want to start your track
That cut of course will be replicated on the metalwork and it will be crossing the mating surfaces of the moulds on the press
It is inherently a weak spot as the VMS set correctly will cut a fairly deep lead in groove
Since the mating surfaces come under extreme pressure from the pressing process if the stamper is to split it will do it right there
The nickel deposit has quite a lot of stress in the grooves so it is quite weak whrever there is a change of direction of the resulting deposit
In actual fact you can get a stamper and once you do a little cut from an even smooth surface to where the lead in grove starts you can easily tear it along the groove with your hand the resolt will look like apple peelings
Quite a few cutting guys when they start out do their test cut first than drive the head across to the start of the music They dont do it for to long though as they get the msg real quick from the pressing plant
So it is best avoided from the start your machine is quite capable of doing it so for you it is possble
Cheers
Chris

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