MM vs MC Phono Preamps Explained

If you are browsing for a new phono preamp (or phono stage) to use with your turntable, then you have likely seen that there are three different kinds of phono preamps.

MM, MC and MM/MC.

  1. Some phono preamps are MM compatible only
  2. Other phono preamps are MC compatible only
  3. Some phono preamps can switch between MM and MC to support both

One example of a MM only phono preamp is the Pro-Ject Phono Box MM. While the Pro-Ject Phono Box is a phono preamp that can switch between MM and MC. The Rega FONO MC is a preamp that is compatible with MC only.

But why are some preamps compatible with MM only while others support only MC? What is the difference between a MM and a MC phono preamp?

  • MM phono preamps work with Moving Magnet (MM) cartridges.
  • MC phono preamps work with Moving Coil (MC) cartridges.
  • MC phono preamps have higher gain than MM phono preamps because of the low signal level of MC cartridges compared to MM cartridges.
  • MC phono preamps usually have a lower noise floor and better noise characteristics than MM phono preamps because of the low signal level of MC cartridges compared to MM cartridges.
  • MM and MC phono preamps have different input impedance to match the difference in output impedance between MM and MC cartridges.
  • MC phono preamps usually have adjustable input impedance and adjustable gain that needs to be adjusted to match the output impedance and output signal level of the specific MC cartridge used. This is unnecessary in MM phono preamps.
Rega Aria MM/MC Preamp with both MM and MC inputs and switches to select MC input load and gain

In the below sections of this article, I will explain the difference between MM and MC in more detail and look into why it is important to choose the right one for your turntable and cartridge. I will also discuss which one, MM or MC, that is the best choice for different needs. And I will show you some of my favorite phono preamps that don’t break the bank.

The difference between MM and MC Phono Preamps

To understand the differences between MM and MC phono preamps in detail, we first need to understand the differences between MM and MC cartridges.

MM vs MC Cartridges

The cartridge is the heart and soul of the turntable. The device that transforms the physical grooves that are carved into the record into an electrical music signal that can be amplified and then converted into sound by the loudspeakers.

On a MM cartridge, there is mounted a permanent magnet on the stylus cantilever. As the stylus tracks the grooves, the magnet that is mounted on the stylus cantilever vibrates between two sets of fixed coils inside the cartridge. The moving (vibrating) magnet inside the fixed coils form a tiny electromagnetic generator that produces the electrical music signal.

On a MC cartridge, the coils are mounted on the stylus cantilever while the magnet is fixed. Here, the moving (vibrating) coils inside the fixed magnet form a tiny electromagnetic generator that produces the electrical music signal.

So one a MM cartridge, the magnet moves with the stylus. While the coils move with the stylus on an MC cartridge.

MC cartridge with coils mounted to the stylus cantilever

To enable the stylus to read the grooves in the records accurately, it is critical that the mass that is mounted on the stylus cantilever is low. To keep the mass low, the coils that are mounted to the stylus cantilever in MC cartridges have fewer windings and thinner wire than the fixed coils that are used in MM cartridges.

The fewer coil windings of a MC cartridge compared to a MM cartridge results in two important differences between MM and MC cartridges:

  1. An MC cartridge outputs a much lower signal level than a MM cartridge
  2. An MC cartridge has much lower output inductance and impedance than a MM cartridge

MM vs MC Phono Preamps

The phono preamp (or phono stage) has two important tasks in a vinyl playing stereo setup.

  1. Amplify the tiny signal from the cartridge from phono level that varies between 0.1 mV and 7.0 mV to a standard line level that is 316 mV.
  2. Increase the bass and decrease the treble to achieve a flat frequency response (RIAA Equalization)

(I recommend that you check out this article where I dig deep into the purpose and function of phono preamps if you want a deeper understanding of phono preamps.)

An MC cartridge has a lower signal output level and a lower output impedance than an MM cartridge. So a MC phono preamp will have different characteristics than a MM phono preamp when it comes to gain, impedance/loading, and noise levels.

Gain

A MC phono preamp must have higher gain than a MM phono preamp. The table below shows typical phono preamp gain levels needed for MC and MM cartridges to reach the standard 316 mV of a line level signal.

CartridgeOutputPreamp Gain
Low-level MC0.1 mV3160X / 70dB
Standard MC0.5 mV632X / 56dB
MM5.0 mV63X / 36dB

As MC cartridges’ output level varies much more than the output level from MM cartridges, MC phono preamps usually come with adjustable gain.

Impedance / Loading

The input resistance and capacitance (impedance) of a MC phono preamp differs greatly from the input impedance of a MM phono preamp. Matching the input impedance of the phono preamp and the output impedance of the cartridge is crucial to achieve a flat frequency response. The table below shows some typical levels for MC and MM phono preamp input impedances.

Phono PreampInput Resistance
and Capacitance
MC100 Ohms
3000 pF
MM47 000 Ohms
100 pF

Noise Levels

A high-quality MC phono preamp usually uses a delicate now-noise circuit design to achieve good signal-to-noise ratios, given the low signal level of MC cartridges. A MM phono preamp can perform well with a slightly higher noise floor than MC phono preamps because of the higher signal level outputted by the MM cartridges.

MM/MC Phono Preamps

MM/MC phono preamp with separate inputs for MM and MC

An MM/MC phono preamp is a phono preamp that includes electronic circuitry to support both MM and MC cartridges. In higher-end MM/MC phono preamps this is usually accomplished by including two entirely separated phono stages. One for MM and one for MC. With load and gain adjustment for the MC input.

Budget MM/MC phono preamps, on the other hand, tend to skip the important load and gain adjustment for the MC input. This might sacrifice some of the sonic performance you want to achieve by buying an expensive MC cartridge.

So if you have invested in an expensive MC cartridge, then it might be wise to choose a high-quality dedicated MC phono preamp that will enable you to extract the sonic potential of the cartridge. Or buy a high-end MM/MC phono preamp that includes a separate high-quality phono stage for MC.

How to tell whether your turntable is MM or MC?

Most mainstream and affordable turntables come with MM cartridges. While MC cartridges dominate the “Stereophile” high-end of the market.

Popular affordable turntables like the Audio-Technica AT-LP120 and the Pro-Ject Debut Carbon come with an MM cartridge. That is also the case for slightly higher end turntables like the Rega Planar 2 and the Rega Planar 3. While the popular high-end Clearaudio Concept turntable can be purchased with both MM and MC cartridges.

Therefore, the price of the turntable is a good guideline to tell whether a turntable has a MM or MC cartridge. Lower priced turntables will almost always have a MM cartridge.

The best way to be sure whether your cartridge is MM or MC is, however, to search the exact make and model description that is printed on the cartridge on Google, Amazon or needledocotor.com. Doing a bit of research on those sites should be a straight forward way to find out whether your cartridge is MM or MC.

Why is it important to choose correctly between MM and MC?

MM phono preamps are designed to match the signal level and output impedance of a MM cartridge. And likewise for MC cartridges and MC phono preamps.

Using a MM phono preamp with a MC cartridge (and vice versa) can cause way too high or way too low signal level being outputted from the phono preamp. This can cause clipping of the music signal or way too low music volume.

Using a MM phono preamp with a MC cartridge (and vice versa) can also negatively affect the flatness of the frequency response because of miss-match between the output impedance of the cartridge and the input impedance of the phono preamp. This will negatively impact the sonic performance of the stereo. Artificially boosting some parts of the music frequency range and artificially dampening other parts of the music frequency range.

What is best? MM or MC?

Audiophiles and Stereophiles generally prefer MC cartridges over MM cartridges. Therefore, the simple answer is that MC is better than MM if excellent sonic performance is the ultimate goal.

MC cartridges are, however, usually very expensive and require a high-end stereo-setup to perform, so MM cartridges might be the best choice for regular vinyl spinners that have not invested in a super expensive high-end turntable and stereo.

The major advantage of MC cartridges is that the mass of the coil that is mounted on the cantilever is lower than the mass of the magnet that is mounted to the cantilever on MM cartridges. The lower mass of the MC cantilever provides for more precise and dynamic reading of the record grooves.

The main disadvantages of MC cartridges are their price and that they require a very precise and low-noise turntable setup to perform well due to their low-level signal output. So the MC cartridges are not only pricier by themselves. They also require a pricy stereo setup to perform well.

On affordable turntables and stereos, MM cartridges are generally preferred because of their lower price and lower requirement for a precise low-noise turntable setup, as they output higher-level signal than MC cartridges.

There are also some high-level MM cartridges available on the market that might provide the same sonic performance as MC cartridges (or close to) without the disadvantages of the MC cartridges. Two examples are the Ortofon 2M Bronze and the Rega Exact MM cartridges.

My Favorite Phono Preamps

Below are the phono preamps that are my favorites. They are all from industry-leading manufacturers. And they have all received very good reviews from HiFi Magazines and critics as well as from the vinyl community.

For MM phono preamps it is safe to choose some of the affordable options if high-end stereophile approve sound is not a must for you. The reason is that the MM phono preamps utilize a simpler and less noise-critical design that MC prone preamps with no need for adjustable gain and impedance.

For MC and MM/MC phono preamps, on the other hand, it might be wise to start look higher in the price range as the most affordable ones don’t tend to be pure and authentic MC phono preamp designs.

So in my recommendations below, the most affordable MM phono preamps start lower in price than the recommended MC and MM/MC phono preamps.

My Favorite MM Phono Preamps

ART DJPREII

PriceLow / Affordable
InputsMM
GainUp to 45 dB adjustable
Input
Resistance
47 000 Ohms
Input
Capacitance
100pF / 200pF switchable

PROS

  • Affordable
  • Good beginner MM phono preamp
  • Adjustable gain
  • Quality metal casing

CONS

  • A good preamp for the money, but might underperform in higher-end stereo systems
  • The extra features (low-cut filter, clip indicator, etc.) might scare purists and audiophiles

Click here to check current pricing at Amazon

Pro-Ject Phono Box MM

PriceLow / Affordable
InputsMM
Gain40 dB
Input
Resistance
47 000 Ohms
Input
Capacitance
120 pF

PROS

  • Affordable
  • Good beginner MM phono preamp
  • Pure dual mono circuit design
  • Very good sound for the money

CONS

  • None at this price point

Click here to check current pricing at Amazon

Rega Fono Mini A2D (My Very Favorite!!!)

PriceMedium
InputsMM
Gain40 dB
Input
Resistance
47 000 Ohms
Input
Capacitance
100 pF

PROS

  • Multi award winning higher-end phono preamp from Rega
  • High quality sound
  • Punchy bass and warm sound
  • Cost-effective version of the Fono MM
  • Can be used to digitize records through USB

CONS

  • Does not look as stylish as its bigger brother, the Rega Fono MM

Click here to check current pricing at Amazon

Rega Fono MM

PriceMedium-High
InputsMM
Gain41 dB
Input
Resistance
47 000 Ohms
Input
Capacitance
100 pF

PROS

  • Multi award winning high-end phono preamp from Rega
  • What HiFi’s Best Phono stage in its price category 2014, 2015 & 2016
  • Awesome sound – Audiophile approved!
  • Nice design

CONS

  • None if you have the money to spend

Click here to check current pricing at Amazon

My Favorite MC Phono Preamps

Rega Fono MC

PriceMedium-High
InputsMC
Gain64db / 70 dB switchable
Input
Resistance
70 / 100 / 150 / 400 Ohms switchable
Input
Capacitance
1000 pF – 4300 pF switchable

PROS

  • Builds on the design from the Rega Aria
  • Audiophile approved sound
  • Compatible with most low output MC cartridges
  • Nice design

CONS

  • None if you have the money to spend

Click here to check current pricing at Amazon

My Favorite MM/MC Phono Preamps

Pro-Ject Tube Box S2

PriceMedium-High
InputsMM and MC
Gain40 – 63 dB
Input
Resistance
MM:
47 000 Ohms
MC:
10, 100, 470, 1000 and 2000 Ohms
Input
Capacitance
47 – 587 pF

PROS

  • A high-quality (and relatively) affordable tube phono preamp
  • Warm sound character
  • Good enough for higher-end stereo systems
  • Fully discrete design (No operational amplifiers)
  • Replaceable tubes for personal sound shaping
  • MC gain and impedance adjustability

CONS

  • Sits in the lower range of phono tube amplifiers and will probably be overlooked by most hard-core audiophiles and tube enthusiasts
  • But not much to criticize at this price point
  • Might not be a perfect fit for all MC cartridges due to slightly limited MC loading range

Click here to check current pricing at Amazon

Rega Aria

PriceHigh
InputsMM and MC
GainMM:41 dB
MC: 64db / 70 dB
Input
Resistance
MM: 47 000 Ohms
MC: 70 / 100 / 150 / 400 Ohms
Input
Capacitance
MM: 100 pF
MC: 1000 pF – 4300 pF

PROS

  • Fully separate MM and MC phono stages
  • High-end and audiophile approved
  • Everything you will ever need from a phono preamp

CONS

  • None if you have the money to spend

Click here to check current pricing at Amazon

Resources

Wikipedia: Magnetic cartridge

Rega Research

Pro-Ject

ART

Is phono stage and phono preamp the same?

Yes, a phono stage is the same as a phono preamp. In the context of vinyl records and turntables, it is also common to only use the word preamp. In a broader context, a preamp might however have a different meaning (and function) than a phono stage and phono preamp.

What is a phono preamp or phono stage?

A phono stage or phono preamp is an electronic device that connects between a turntable and an amplifier/receiver that convert the phono signal from a turntable cartridge to a line signal that is compatible with the line/aux inputs on common amplifiers, receivers and active speakers. The phono stage to phono preamp can also be built into turntables and receivers.

What is the difference between PHONO and LINE?

A line signal has a standardized signal level of 316 mV and a flat frequency response. A phono signal has a signal level that varies from 0.1 mV to 7.5 mV (depending on the cartridge in use) and has reduced bass and boosted treble. You can read more about the difference between phono and line in this article.

  • Tom
  • June 29, 2019