Choosing the right cartridge

Researching and choosing Hi-Fi separates incorporating a record deck isn't as straight forward as it may initially appear. For some techies, the research is part of the fun, but generally the turntable/arm/cartridge choice seems to generate most uncertainty and angst. It shouldn't be so. After all, the record deck has just two main functions; to rotate the platter at the correct constant speed with no variation (wow and flutter) or noise (rumble). The pick-up arm, which supports the cartridge, has to avail optimum performance from the little mite. The first of these idealistic criteria is down to the manufacturer to produce a quality, well manufactured turntable/motor/bearing etc., but the second involves you and your friendly expert dealer who will set up the arm and cartridge...

“Yes Sir, we can certainly do the setting up for you, but which cartridge had you in mind?” Mmm...there's a thought. This article will hopefully help clear the fog a little with regard to cartridge choice. Of course, the experts at Hi-Fi Corner will advise on your cartridge options, but it may be worth your while to be across a few facts for yourself.

The main considerations are:

  • Compatibility of the cartridge with an existing amplifier/phono stage, or one you have already purchased “from a friend at a good price”.
  • Your involvement. Would you prefer more of a plug in-and-play approach or are you okay with a bit more groundwork and experimentation yourself?
  • Cost - not just that of the cartridge but the associated equipment to make it work.

There are basically two types of cartridge available, moving-magnet (MM) and moving-coil (MC). Both types work by producing low level electrical signals generated in a slightly different way. However, there are important differences as to the nature of the signal produced and how it is presented to the phono amplifier. A phono amplifier sits between the cartridge (record deck arm cables) and the pre-amplifier, and is necessary if you wish to play vinyl records. There are a few integrated amplifiers with built in phono stages such as the Rotel A14 integrated, but generally pre-amplifiers/amplifiers have line level analogue inputs which are not suitable for plugging in a record deck directly. An external phono stage is required.

Moving-coil vs. Moving-magnet cartridges.

Output signal level. The output signal voltage of a moving coil cartridge is usually much smaller than that of a moving magnet model, sometimes as low as one-tenth, so you will require a phono stage with a specific moving coil cartridge input that can provide the extra gain required. The level of the signal varies from manufacturer to manufacturer and model, but typical values of the electrical signal produced from each type of cartridge are:

MC : 0.15 millivolts - 0.5 millivolts,

MM :1.5 millivolts - 3.5 millivolts.

All these are tiny voltages but the MC one is miniscule. It's amazing it works at all!

A MC phono stage should ideally have a good range of gain options to accommodate the particular MC cartridge you choose, whether it's one that produces 0.2 mV or three times this voltage. If you plan on using a low output MC cartridge, look for a phono stage that provides flexible gain options, say between 40 dB and 70 dB. For a MM cartridge or high output MC cartridge, the phono stage will typically have gain of around 32dB and should be  be less expensive. A high-end phono stage such as the EAT E-Glo provides a wonderful range of options and would allow a wide choice of MC cartridges. If you plan on never going down the MC route, something such as the Graham Slee Gram Amp 2 unit would do any MM cartridge justice, at a considerably lower cost. The majority of phono amplifiers are switchable between both types of cartridge.

Also available are high-output MC cartridges which require less gain than usual MC cartridges – a sort of half-way house between MM and MC if you will. These should certainly be considered, especially if you already own a phono stage with just a MM input. The strong likelihood is that a high output MC cartridge will produce an improvement over a conventional MM model, but perhaps won't be quite as refined as a reasonable low output MC one. Having said this, companies like Dynavector and Ortofon produce high performing higher output MC cartridges such as the DV10X5 II, DV 20X2H. Hana manufacture the excellent value EH, SH, and MH models.

Resistance loading.

Aside from output voltage, the other technical consideration with MC cartridges is loading. This is electrical resistance the cartridge signal expects to be confronted with at the phono stage input. Resistance is measured in ohms. The cartridge is in reality a form of engine, and the power it creates needs a load to work into, otherwise it can't produce anything. A bit like a crane with nothing to lift. Indeed, if there was no input resistance from the amplifier, i.e a short circuit, there would be no sound.

The situation is much simpler with MM and most higher-output MC cartridges. The standard load resistance required for MM cartridges is 47K ohms and this is what manufacturers adhere to. There is a rather esoteric argument against this standard, but this is beyond the scope of this article (and probably myself).

The load resistance required for a low output MC cartridge is much lower, and just to complicate matters, there is no standard value for anyone to adhere to.

Now the next bit gets a bit messy, but please bear with me as it's a useful reference when setting up.

The amplifier/phono stage load impedance required by low output MC cartridges is typically between 1x and 5x the internal impedance of the cartridge itself, as specified in the manufacturers blurb . Take the Dynavector Karat 17D3 for instance. This has an internal impedance of 32 ohms, and the manufacturer recommends a load resistance greater than 100 ohms. That's plain enough, but, like most things, life isn't always straight-forward. That 100 ohms is a useful starting point but, if you have a good, flexible phono stage, you can try changing the loading to 150 or 200 ohms... you little devil you! So what's the point of this act of rebellion? The sound character is likely to change slightly or even a lot, depending on the make and model of cartridge. As a rule of thumb, with a lower input resistance setting of say 100 ohms (for the Dynavector), the sound-stage will become deeper and more precise, but can sound less dynamic. With a higher input resistance setting, say 200 ohms for this example, the overall performance is brighter and is more dynamic, but definition and precision are decreased. An input resistance higher than 500 ohms for this cartridge will result in very minor changes to the sound characteristic. Which setting you choose is down to your own aural preference, but for Karat 17 D3, don't have a setting below 100 ohms or beyond 250 ohms. This pattern of loading vs sound character is generally applicable to MC cartridges.

Here at Hi-Fi Corner, an extensive range of MC phono stages are available from the Musical Fidelity V90-LPS, to the exotic truly reference standard Vitus Audio MP-P201. It's worth considering a MC phono stage that will provide a variety of loading options, especially if you may be upgrading your cartridge at some point in the future. The staff at Hi-Fi Corner will offer all the advice you need to help you choose.

It's worth mentioning that, instead of a MC phono stage amplifier, you can utilize a step-up transformer to produce the extra gain required by low output MC cartridges. If using a step-up transformer such as the excellent Ortofon ST-80 SE, cartridge resistance loading should only be between 1x and 5x that of the cartridge internal impedance, significantly lower than when using a powered MC phono stage. The step-up transformer will still require a 47Kohm MM input to work into – it cannot be plugged straight into the line input of your pre-amplifier. The advantage of a transformer is a reduction of noise as it's a passive device. Transformers are undoubtedly capable of great dynamics, but they're not generally as versatile as a good active MC phono stage, often designed with a particular range of cartridges in mind. Whilst a step-up transformer isn't usually horrendously expensive (although it can be), you have to budget for a MM phono amplifier as well if you don't already have one.

On the subject of costs, generally speaking, a good moving magnet cartridge is less expensive than a good moving-coil one. A great entry-level MM cartridge is the Ortofon 2M Red with all the pedigree and performance associated with that brand. The equivalent entry-level MC version is the Quintet Red, but at over twice the price. There are superb performing MM cartridges such as the Ortofon 2M Black and Sumiko Amethyst, both of which will provide good detail, big sound-staging and tracking ability without the need for a high gain MC phono stage. High-end MC cartridges such as the superb Lyra Atlas are expensive and beyond compare, but here we're at the top of the tree price-wise. At Hi-Fi Corner we have a vast range of cartridges available at all price brackets, so there'll be something to suit every need. Click here to see our range of moving-magnet cartridges and moving-coil models

One other point to bear in mind is the physical weight of the cartridge. Moving-coil cartridges are often slightly bulkier and heavier than their MM counterparts. This isn't always the case by any means, but it may be worth checking out the maximum weight of cartridge your pick-up arm will accommodate. Most pick-up arms will balance nearly all cartridges, but it may be worth checking under "maximum cartridge weight" in the arm manufacturers spec sheet. It also used to be the case that MM cartridges were better at tracking difficult grooves, but this has largely been dispelled with modern MC cartridges that are set-up correctly.

Finally, (phew!)...all cartridges require a decent “run-in” time of say 25-50 hours to sound reach their full potential, so don't judge a brand new one too harshly too quickly. After that time, you moving-coil boffins can go to town experimenting with resistance loading. Just don't forget to listen to the music though!