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April 5, 2022

Dave Kutch protecting the cutter head

Where there’s friction, there’s heat. In a vinyl cutting lathe, a tiny vibrating ruby stylus etches grooves into a spinning lacquer disk, creating plenty of friction and heat. The latter is high enough to potentially damage the rare and expensive vinyl cutter head.

In episode 21 of “Start to Finish: Dave Kutch - Episode 21 - Cutting To Vinyl Part 2,” Dave and cutting-engineer par-excellence Mark Santangelo explain the feature in the Neuman VMS 70 lathe that mitigates potential heat-related damage to the vinyl cutting head.

Gas it Up

Physically, the VMS 70 lathe isn’t a single unit. It’s a sprawling apparatus of interconnected components, including not just the platter and vinyl cutting head but a separately housed pitch computer, a tall equipment rack full of amplifiers, metering devices and more.

The VMS-70 at Kutch’s facility, The Mastering Palace.
(image from themasteringpalace.com)

Also attached to the VMS-70 are a pair of helium tanks. Helium gas is the critical ingredient that keeps the heat at the vinyl cutter head under control. The gas is constantly fed to the cutting surface through a tube to keep the temperature under control during cutting.

“Helium is an inert gas that does not take on heat,” Dave says. “Wherever it's feeding will stay in a relatively neutral temperature.”

Mark checks the pressure of the helium to make sure it’s not too high. It it is, it could create noise that gets written to the disk.

Helium comes from the external tanks into a reservoir next to the platter (highlighted), from where it’s sent to the point of the cutting.

Hot High Notes

On the far right of the VMS 70 is a rack that houses, among other components, a circuit breaker that will trip if the cutting area gets too hot. It also houses meters for both the left and right channels that measure the heat at the point where the stylus meets the lacquer. Mark explains that the higher the audio frequency, the more heat generated.

Meters for each channel let the engineer monitor the heat level at the vinyl cutter head.

The meter has other uses, as well. When you cut a lacquer disk, one of the “side effects” of the process is that it increases sibilance. Watching the meters for peaks helps the mastering engineer informed of frequency peaks that could cause sibilance to be written to the lacquer.

Keeping it Clean

If you watched the previous video in the series, Start to Finish: Dave Kutch - Episode 20 - Cutting To Vinyl Part 1, you’ll remember that the cutting lathe uses suction from a vacuum to hold the lacquer disk in place and to clean up the residue (“the chip”) that results from the cutting process.

Although suction from the built-in vacuum gets rid of most of the excess (aka “the chip”), residue often gets stuck on the vinyl cutter head at the end of a session. For that reason, Mark says, he always cleans the stylus right after using it. Otherwise, it could harden on there, which would be problematic. “We don't want that,” he says, “because if there's any chip that hardens on it, it’s going to create scratches and streaking within the grooves, and noise.”

Cleaning the vinyl cutter head after a session.

Mark also points out that he’s never sure how well a stylus will perform. “They are small, expensive, and very finicky,” he says. “You get lemons sometimes, and then you get ones that you can cut with for months, and they sound fantastic.”

Vintage Advantage?

Watching a vinyl cutting session, it almost feels like you’re looking back in time. The cutting lathe seems like a museum piece rather than a still-used device. The New York Times’ Ben Sisaro described a lathe of similar vintage to the VMS 70 as looking like “something from a World War II submarine.” A significant reason that vinyl production still depends on 40- and 50-year old lathes is that the resurgence in the medium was completely unexpected.

After the CD overtook LPs in sales back in 1989, vinyl appeared to be in a death spiral. But despite the subsequent popularity of digital downloading and then streaming, sales of vinyl LPs have risen every year since 2006. Last year, sales increased by a whopping 50 percent. Putting out a vinyl version of an album is now an integral part of an artist’s release strategy. The artists’ profit from vinyl is infinitely bigger than the pittance they get from the streaming services.

Sales of vinyl records have increased every year since 2006.

Over the last few years, the demand has outstripped the supply, which is still being produced, for the most part, by a small number of pressing plants leftover from vinyl’s golden age. Finally, some new facilities are starting to come online, but vinyl production lead time is still usually measured in months.

If you don’t have time to wait, some mastering facilities even offer “lathe cut” vinyl records, which are cut directly from a lathe rather than going through the normal process of electroplating the lacquer master and creating a stamper from it to use in a vinyl pressing plant.

Now that vinyl has re-established itself as an essential part of the music industry; it will be interesting to see if someone will invent a way to manufacture records that’s not based solely on 20th-century technology.

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