How to choose the right cartridge for your turntable

Posted by U-Turn Audio on

Put in brutally simple terms, turntables work by dragging a tiny diamond through the grooves of a record. The cartridge's job is to convert the resulting vibrational energy into sweet, sweet analog sound. There is a large amount of musical information encoded in records - so it should be no surprise that the quality of your cartridge has a big impact on sound quality. 

We offer a choice of four cartridges on our turntables, and we are often asked about the differences between them. Today's post will help explain this. But before diving in, let's go over some cartridge fundamentals. Things are about to get technical.

What exactly is a phono cartridge?

The cartridge is an electro-mechanical device that translates the information in record grooves into an electrical signal that can be amplified to produce music.There are many different types of cartridges. To keep it simple, we will focus on the operation of a moving magnet or MM-type cartridge (many of the principles remain the same for moving coil cartridges).

The diamond stylus tip is the only part of the cartridge that makes direct contact with the record. As the stylus traces the movements of the grooves, it vibrates the cantilever. The cantilever is a rigid tube with a stylus mounted on one end and a magnet on the other. The rubber suspension allows the cantilever to pivot so that the stylus can accurately track the grooves.

Vibrations from the stylus tip travel along the cantilever to the magnet. As the magnet vibrates, its magnetic field varies. These variations in the magnetic field generate a small voltage in the coils, which corresponds to the movement of the magnet (thanks to Lenz's Law). This signal is then passed through a phono preamp (for RIAA equalization) before reaching the amp/speakers, which convert the electrical signal into sound.

(SIDE NOTE: To get a stereo signal (left and right channels), this configuration is essentially doubled. Two magnets are attached the cantilever at a 90 degree angle each with a corresponding set of coils. For more info on how stereo cartridges work, check out this article.)

What to Look for in a Cartridge

Stylus shape: The shape of the stylus affects how it makes contact with the record groove. The narrower the contact radius, the better the stylus will be able to track modulations in the groove. The two most common shapes of styli are conical and elliptical. Elliptical shaped styli have a smaller contact radius than conical styli - this allows elliptical styli to trace grooves more accurately and extract more musical information (especially high frequencies). 

Cantilever: In order to effectively transfer vibrational energy from the stylus tip to the magnet (or other generating element), it is critical that the cantilever be as stiff and light as possible. The material, size, and construction of the cantilever affect how well a cartridge can reproduce a range of audio frequencies. The most common material used in cantilevers is aluminum alloy, although carbon, boron, and certain copper alloys are often used. 

Trackability: This spec describes how well the stylus can track a modulated record groove. Trackability is measured by recording the maximum amplitude that a stylus can trace before the signal is distorted. Trackability is influenced by many factors - including stylus shape, cartridge alignment, and tonearm compatibility. The spec is often listed in micrometers (μm) - the higher the trackability spec, the better.

Generator type: The two main generator types are moving magnet (MM) and moving coil (MC). MM cartridges are most common. MC cartridges tend to be lower output and require a preamp with a special MC setting. MC cartridges are generally more expensive. All of the cartridges we offer are MM, but if you are looking to take your Orbit to the next level, you might want to consider installing an MC cartridge like the Denon DL-103R. For more technical info on MM vs. MC cartridges, check out this article.

Mount type: Most cartridges (including all of ours) are standard mount. Standard mount cartridges are secured to the tonearm by 2 vertical screws spaced 1/2" apart and feature four small posts for connecting the tonearm leads. P-mounts have four slender pins that plug directly into tonearms specifically made for use with P-mount cartridges (our tonearms are not made for this).

Comparing cartridges

Now that we know a little bit about how cartridges work, let's dive into some of the different cartridges we offer:

Audio-Technica AT91b 

Stylus: Conical diamond
Generator type: Moving Magnet
Cantilever: Carbon
Trackability*: 70 μm

The AT91b is an excellent beginner cartridge. It features a moving magnet generator and carbon cantilever, which provides solid bang-for-your-buck. The main drawback of the AT91b is that it has a conical stylus, which limits its trackability.

Available on the Orbit Basic and Orbit Custom.

Ortofon OM 5E

Stylus: Elliptical diamond
Generator type: Moving Magnet
Cantilever: Aluminum
Trackability*: 80 μm

Built in Denmark, the Ortofon OM 5E is known for its versatility and neutral sound signature. It is a great choice for listeners who enjoy a wide variety of genres. The OM 5E's elliptical diamond stylus gives this cartridge an edge over the AT91b both in terms of trackability and overall resolution and clarity. The OM 5E's stylus can be swapped for any of Ortofon's Super OM series styli, which makes this the most upgradable cartridge we offer.

Available on the Orbit Custom.

Grado Black1

Stylus shape: Elliptical diamond
Generator type: Moving Magnet (Flux-Bridger)
Cantilever: Aluminum (3-piece)
Trackability*: 80 μm

Grado cartridges have been hand built in Brooklyn, NY since 1953. The Black1 features an elliptical diamond stylus mounted to a unique 3-piece cantilever. As with all cartridges in Grado’s Prestige series, the Black1 uses a proprietary Flux-Bridger generator system – which is similar yet distinct from moving-magnet technology. These unique features give Grado cartridges their signature "warm" sound.

Available on the Orbit Plus and Orbit Custom

Grado Blue1

Stylus shape: Elliptical diamond
Generator type: Moving Magnet (Flux-Bridger)
Cantilever: Aluminum (4-piece)
Trackability*: 80 μm

The Blue1 uses much of the same technology as the Black1, including Grado’s Flux-Bridger generator system. One major difference is the 4-piece OTL (optimized transmission line) cantilever used in the Blue1. This more advanced cantilever uses a unique telescoping construction and special damping compounds to bring out even more warmth and detail, which is especially noticeable in higher frequencies.

Available on the Orbit Custom.

*Trackability measurements recorded in-house using Clearaudio's 'Trackability Test Record'. All cartridges were subjected to a 2 hour break-in period before being tested. Recorded measurement is maximum amplitude the stylus could track without significant distortion (@ 333 Hz).

Older Post Newer Post