Recording - September 2019 - 52

CUTTING VINYL

with Stephen Marsh

IN THE LATHE ROOM
Can you walk us through how the lathe
actually works?

circa 1957. Getting that strong, muted trumpet sound to translate at the smaller diameter took a few tries!

This one is cantankerous! [laughs]. The first thing we do in the
morning is lube it up, check the belts, run the motor for a while
to optimize its speed, let the amps warm up-it's like an old car.

What happens when you get to the end of the cut?

And what about the vinyl cutting process?
The first thing we do is pull your audio up and get it
prepped. Then we'll go through and get our settings on the
analog gear. If it's from analog tape, that's when we set up
the EQs for the first two songs in the A/B setup. If it's coming
from digital, most of the processing will generally be done
already. Then we'll cue it up and get our levels, making sure
that the songs are all sitting good together level-wise.
Next, we check the ruby cutting stylus with a video microscope and make sure it's good. Then we put a fresh lacquer
on the turntable, turn on the vacuum and stylus heat, drop the
half-nut, engage the feed, drop the head, and we're cutting!
Once the head is dropped, we swing the microscope over
and make sure that the groove is looking good and is the right
width and depth, the right LPI (lines per inch) for the program
we're cutting, and then we roll audio.
Usually, I'll leave three or four rounds of catch groove on the
very outside, and then I'll pull the LPI up to program spec and
do one rotation before the audio starts. The way this lathe is set
up right now is completely manual. So, I watch through the microscope as the cut goes down and I reference the screen and
watch the audio amplitude so I have an idea of what's coming
up. As we cut, we're looking through the microscope, pushing
in lead-ins, lead-outs and gaps, all while riding the pitch wheel
by hand in real time. It's one continuous process and we can't
pause and restart once we drop the cutting head. It's part performance art, and we like that.
In the next few weeks we'll be installing a computerized automation system that will look at the audio in preview and be
able to automatically vary the LPI and the depth of the cut. It
also captures the LPI info and stores that as MIDI data so it can
be recalled for future re-cuts.

Do you usually get your master on the first try, or do
you screw up a lacquer or two before you get the
final one?
I expect to burn a 12-inch lacquer dub as a reference, because
perhaps the greatest bugaboo with cutting vinyl is the linear
velocity and how it falls off so dramatically across the playing
surface. How things are going to cut and be reproduced from
the outside of the disc really varies a lot from the inside of the
disc. So, I'll pick a couple of spots and test cut them at about
the diameter they're actually going to be cut at, to make sure
everything is consistent.
We recently cut a 7" for the new Ed Norton Film Motherless
Brooklyn that features Thom Yorke on the A side and Wynton
Marsalis on the B side playing a song in the style of Miles Davis
52 RECORDING September 2019

When the audio ends, we push through to the specific end
diameter required, which is slightly different for 7", 10",
and 12" records, and then we cut a locked groove so there's
something to catch the needle at the end of playback.
Lift the head, pull the lacquer out, and pack it very carefully-
this is what gets sent immediately to the plating facility.

And that is where they make the stampers?
Yes. They'll wash it down and then they'll spray it. They spray
it with silver and they put it into a nickel plating bath. Once that
nickel layer is thick enough, they'll peel it off and then do the
same thing again to that which is now a negative image of your
lacquer. They make a new pull off of that which gets you back to
the positive, and from that they pull the actual stampers.

Why do the master lacquers look bigger?
They are 14" mostly because the stamper needs to be slightly
larger than the finished disc. It also it gives you a test area so that
you can calibrate your groove geometry on the actual physical disc
you're going to cut, which lets you cut more accurately.

When we were kids, albums were single LPs with
four to six songs per side, and maybe Kiss or Peter
Frampton would put out a double album on occasion.
Now, I'm seeing reissues of these same classic records and vinyl from new bands being double, triple,
and quadruple sets-why?
A host of reasons, beginning with fidelity. With fewer songs,
we can cut wider grooves which translate into better bottom
end, better overall disk level, and it allows us to keep the songs
toward the outside of the disc, which translates into more consistent high frequency response across the disc surface. It's also
easier to manage an all-analog cut when you only have to contend with three or four songs per side. On occasion, it allows for
45 RPM cutting, which again aids in better top end response.

If an artist is thinking about pressing a project on vinyl, is there anything they need to consider at the
creation or mixing stage?
Often there is some stuff that just physically cannot be cut to
vinyl. Because a cutting head is electromechanical, not electromagnetic like tape, or even just a digital converter, the transference medium is completely different.
What's driving the cutting head is a power amplifier, and
inside the cutting head are voice coils, but instead of adding a
cone on them like a speaker, they're connected to a ruby stylus.
One coil pushes one way for one side of the stereo signal, and
the other coil pushes the opposite way, creating this 45/45
side-to-side movement that has specific limitations.
Recording - September 2019

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