Cartridge 101: How Does Vinyl Work?

Cartridge 101: How Does Vinyl Work?

Vinyl records have come a long way since Thomas Edison first recorded sound onto a wax-coated cardboard cylinder back in 1877. Primitive though it was, Edison’s phonograph, and later the Gramophone, developed by Emile Berliner in 1886 (which he and Edison would battle over patent and trademark rights) which used a flat disc, still shared a common, core technology – using a stylus to capture sound waves via a record’s groove, and then play it back. Nearly 150 years later, people still wonder “how does vinyl work?”

What made Berliner’s process unique was the initial concept of creating a master stamper, so that multiple copies of the record could be made and distributed. Today, this step has gone much further by using a master lacquer, and metal stampers, but Berliner was right on the money with his initial concepts. He was well ahead of his time and I wonder if he would have had any idea what a resurgence this technology would be enjoying in the year 2021.

While most of the surviving Edison phonographs and early Gramophones are now relegated to museums, there are some audiophiles that collect them, so an audition might not be as far out of reach as you think. Though primitive compared to today’s modern record players if you get a chance to hear an Edison cylinder or early shellac record (78 rpm, of course) it’s worth the trip down memory lane. It doesn’t get more analog than using a hand crank to wind up a Victrola, and its large horn that connects right to the vibrating stylus assembly, with no need for an amplifier of any kind.

The playback of these primitive record players is surprisingly dynamic, but with very limited high and low-frequency content. And they are all mono recordings. 100 years later it’s still about a stylus following a groove from beginning to the end of a spinning record.

A Brief History of Vinyl Records

The biggest problem the record industry faced with 78 RPM records was record wear. This was due to the primitive stylus assemblies, high tracking forces, and how fragile the grooves in the shellac records were. Though experiments were done, and longer playing records (at 33 1/3 rpm) were used in radio stations for broadcast transcriptions, the first vinyl LPs (or “long-playing records”) were introduced as a commercial product in the summer of 1948. At the Waldorf Astoria hotel in NYC, no less!

This overcame the last major problem from the 78 r.p.m. era: playing time. Now thanks to a finer groove, and the slower playing speed, a vinyl disc could hold 22 minutes of music on one side. And as the collectors in the audience know, a few recording wizards have managed to squeeze even more time onto an album side, albeit with some sacrifices in dynamic range. For the next ten years or so, recordings were still mono. Playback quality had increased tremendously, however. Some music collectors consider this to be the golden age of the phonograph, with early mono pressings of famous jazz, classical, and rock records the best hi-fi has to offer.

How Does Vinyl Work: Stereo vs. Mono Records

how does vinyl work, magnification of a record groove

If you’ve ever seen a high magnification photo of a stereo record groove, you’ll see information cut into both sides of the record groove. This is literally the electrical signal of the left and right channels translated to the groove. When the tonearm is set down upon this groove to play music, the stylus not only moves left to right but actually moves up and down a bit as well.

As a mono record only has a single channel, the groove only goes side to side, making a mono cartridge’s job easier, as it only requires compliance in the horizontal axis. In the 1960s, when many popular records were released in stereo and mono versions, early audiophiles could play mono records on a stereo setup (because the stereo cartridge had increased compliance and a thinner profile stylus) but playing stereo records on a turntable only possessing a mono cartridge could cause damage to the delicate grooves.

How are Vinyl Records Made?

Until just recently, music was recorded on tape, and it had to be transferred to a phonograph record by mechanical means, which is almost a reverse process of how we play records back. The delicate electrical signal from the tape recorder (or analog to digital converter, if from digital files) is sent to a mastering lathe, which uses a tonearm and looks a lot like a record player. Another big difference is the turntables we use today use belt drive or direct drive. Because the mastering lathe needs as close to perfect speed accuracy as is possible, and requires additional torque, mastering lathes are all direct drive.

One of the biggest differences is that the cutting head looks like a giant phono cartridge. It uses a stylus/cantilever assembly of beefier proportions to actually cut grooves in a bare lacquer disc, which is then used to make metal “stamper” plates. In all, it’s just a more refined version of Berliner’s original process. Depending on the production run of the album, multiple stampers are created, as these stampers can only be used to press so many records before they start to degrade. In vinyl’s heyday, multiple lacquers would be cut, and stampers created so that 45 million copies of The Eagles Greatest Hits could be created.

As low bass frequencies have larger grooves, and high frequencies smaller, more densely packed ones, and we can only fit 22 minutes of music on an album side, the signal must be equalized. To make a long story short, the low frequencies (bass) must be reduced and the high frequencies (treble) must be increased so that a more uniform groove can be cut into the lacquer’s surface. This accomplishes two things: more music can fit on a record, and your cartridge’s stylus doesn’t have to work as hard to extract the music from the grooves.

If you take a close look at the grooves in your favorite album, you’ll notice that from the outer groove at the beginning of the record all the way to the innermost groove, the approximate width of the grooves stays a consistent size.

This had to be done in a repeatable fashion, so everyone’s records would sound the same on a variety of different equipment. The Record Industry Association of America (RIAA) established a standard so that when you select the phono input on your preamp or receiver, your records sound correct. It wasn’t until the mid-1970s that everyone was in agreement on this standard, so some earlier records have slightly different equalization curves. If you are buying today’s records, no worries, but if you start to collect records from the early days of vinyl, at some point you will probably want to address this issue.

Are Mono Records Better Than Stereo on Vinyl?

stereo vs mono record beatles

Hard core collectors will argue that a high-quality mono recording can outperform a stereo record, specifically in terms of dynamics and punch. Much of this is due to the slightly wider grooves of a mono LP. For many of us, it boils down to a matter of taste and personal preference. To get a taste for this, there are a number of great examples on the web to listen to, or if you can, the Beatles catalog is available in mono and stereo on compact disc.

The reason we mention digital files in the context of an analog forum like this is that to get true mono reproduction, you will need a dedicated mono cartridge. Current stereo cartridges will play mono records, but because of the nature of a stereo cartridge, you will merely get a “summed” effect, as you would by pressing the mono button on your preamplifier (if so equipped). This will give you a good taste of what mono is capable of, but not all of the dynamics a mono cartridge is capable of delivering.

The dynamics of 78 RPM records can only be approximated on most systems, but it especially true because to play 78s back without damaging the discs, you need a stylus with a different profile. Fortunately, if you have a Sumiko cartridge, you can take advantage of merely replacing your turntable stylus and plugging a dedicated 78 RPM profile stylus in. Again, playing a mono record back with a stereo cartridge will not physically damage the surface of the mono record, but playing a 78 RPM record back without a stylus specifically designed for 78s will. Are you ready to buy that second turntable yet?

Is “True Analog” Possible Today?

jack white analog studio
Jack White is one of the few modern musicians dedicated to the challenge of staying true to an analog recording process

Today, precious few analog records are actually produced from start to finish in analog. There are enough factors for this trend to populate numerous more articles in our series, but to make a long story short, few all-analog recording studios still exist. The massive mixing consoles and 2-inch reel to reel tape decks that captured 48-tracks of electrical signals at the same time, (aka, the “master tape”) are in short supply. These days, when you can get them, a single reel of two-inch tape can fetch a four-figure price tag. It’s just not a cost-effective way to record sound anymore.

While not “digital music” per se, with the ease of digital recording, and digital studio tools, many of today’s albums start out as a high-resolution digital recording, edited in the digital domain, then transferred to an analog master tape, and then cut to a master lacquer. The rest of the process from the master tape is the same.

If you look at the blank space or “dead wax” between the end of the groove and the label, there are a series of numbers that indicate which stamper and lacquer were used to make your album. This is not much of an issue today, as records are very rarely pressed in runs of more than 5 or 10 thousand discs. However, to collectors, the closer you are to the original lacquer not only will determine a record’s sound quality but its collectability. We’ll touch on this in a future article.

You don’t need to wear a foil hat to be a record collector, but you might think it helps sometimes. You don’t even have to have a complete answer if asked “how does vinyl work?”

Building a music collection around vinyl records can be exciting, rewarding, educational, but most of all fun. You can get as involved as you’d like, and with the internet at your command, it’s easier than ever to get in the game.





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