Audio T Verdict
The Rega Fono MM Mk5 is a compact dedicated phono stage designed to get more from a moving magnet cartridge without adding complicated adjustments or controls.
Its fully discrete input stage, carefully selected capacitors and two-stage RIAA equalisation provide a substantial step up from many basic phono inputs built into affordable amplifiers and turntables.
It is particularly well matched to Rega's Carbon and Nd moving magnet cartridges, although its standard 47 kilohm input loading also makes it suitable for a broad range of conventional moving magnet designs.
The Fono MM Mk5 is deliberately focused. It does not support conventional low-output moving coil cartridges, offer adjustable loading or include a USB output. For a straightforward moving magnet system, however, that simplicity is part of its appeal.
Rega Fono MM Mk5 Phono Stage
The Rega Fono MM Mk5 is a dedicated external phono pre-amplifier for turntables fitted with a moving magnet cartridge.
A cartridge produces a much smaller electrical signal than a CD player, streamer or other conventional source. The Fono MM amplifies this signal and applies the required RIAA equalisation before passing it to a normal line-level input on an amplifier.
The Mk5 is housed in Rega's current compact aluminium case, matching products such as the Neo Mk2 turntable power supply and Fono MC Mk4 phono stage.
Operation is intentionally simple. Connect the turntable to the input, connect the output to a spare line input on the amplifier, attach the supplied Rega power supply and switch the unit on.
Why Does a Turntable Need a Phono Stage?
The electrical signal generated by a moving magnet cartridge is far lower than the signal produced by most other Hi-Fi sources.
Records are also cut using a standard frequency curve that reduces bass and increases treble during manufacture. A phono stage must reverse this process accurately during playback.
The Fono MM therefore performs two important functions:
- It amplifies the low-level cartridge signal to a usable line level
- It applies the correct RIAA frequency equalisation
Without a phono stage, a turntable connected to a normal line input will sound extremely quiet, thin and lacking in bass.
Dedicated Moving Magnet Design
The Fono MM Mk5 is designed specifically for moving magnet cartridges.
Its fixed input loading of 47 kilohms in parallel with 100pF follows the standard normally used by conventional moving magnet cartridges.
Gain is fixed at 41.4dB, allowing the phono stage to be installed without the user having to select gain, resistance or capacitance settings.
This makes the Fono MM particularly straightforward for customers who want a correctly matched phono stage without a row of switches or adjustments.
Fully Discrete Input Stage
The Fono MM uses a fully discrete, cascaded and complementary amplifier input stage.
Rather than placing a single general-purpose integrated amplifier at the input, Rega has developed a dedicated transistor circuit for the requirements of a moving magnet cartridge.
This stage provides the gain required by the cartridge while maintaining the low noise and linearity needed when handling such a small signal.
- Fully discrete input circuitry
- Cascaded complementary amplifier arrangement
- Designed specifically for moving magnet output levels
- Fixed gain and loading for simple operation
- No digital processing within the audio path
Two-Stage RIAA Equalisation
Rega divides the RIAA equalisation into two separate stages to reduce interaction between different sections of the correction circuit.
This approach is designed to maintain accurate frequency response while reducing the compromises that can arise when the complete equalisation curve is handled by one stage.
Rega specifies RIAA accuracy of better than plus or minus 0.2dB between 100Hz and 100kHz when used with a suitable output load.
Selected Signal-Path Components
Polyester capacitors are used within the main signal path.
Polypropylene capacitors are used within the RIAA equalisation circuits, where stable and accurate component values are particularly important.
The circuit and component choices are intended to provide consistent channel performance and accurate tonal balance without introducing unnecessary complexity.
What Changed with the Mk5?
The change from the previous Fono MM Mk4 to the Mk5 concentrated on the external casework rather than introducing a completely new audio circuit.
The established Fono MM electronics were retained and rehoused in Rega's updated compact aluminium enclosure.
This brought the product visually into line with the Fono MC Mk4, Neo Mk2 and Rega's wider range of current electronics.
Compatible Rega Cartridges
The Fono MM Mk5 is well suited to Rega's current moving magnet cartridge range.
Rega Carbon
The Carbon is fitted as standard to several Rega turntables, including the Planar 1 and selected Planar 2 packages.
The Fono MM provides a straightforward external phono-stage upgrade for systems using the standard Carbon cartridge.
Rega Nd3
The
Rega Nd3
uses a bonded elliptical stylus and Rega's neodymium moving magnet generator.
It is a natural partner for the Fono MM in Planar 2 and Planar 3 systems.
Rega Nd5
The
Rega Nd5
adds a nude perfect elliptical diamond stylus for improved tracking and detail retrieval.
It is particularly well suited to a Planar 3 partnered with the Fono MM and optional Neo Mk2 power supply.
Rega Nd7
The
Rega Nd7
uses a fine-line nude diamond profile and remains a moving magnet design despite its higher performance.
It can therefore be used with the Fono MM, including in suitable Planar 6 and Planar 8 systems.
Suitable Turntables
The Fono MM can be used with any suitable turntable fitted with a compatible moving magnet cartridge and conventional phono-level RCA output.
Rega Planar 1
The
Rega Planar 1
includes a factory-fitted Carbon cartridge and can connect directly to the Fono MM.
This provides a useful upgrade when the partnering amplifier has no phono input or only a basic built-in stage.
Rega Planar 2
The
Rega Planar 2
can be partnered with the Fono MM when fitted with a Carbon, Nd3 or another suitable moving magnet cartridge.
Rega Planar 3
The
Rega Planar 3
with an Nd3 or Nd5 is one of the most natural system partners for the Fono MM Mk5.
The phono stage and cartridge can both be upgraded independently as the system develops.
Not Intended for the Planar 1 Plus
The Rega Planar 1 Plus already contains an internal phono stage and produces a line-level output.
It should connect directly to an AUX, CD or Line input and should not be connected through the Fono MM Mk5.
Moving Magnet or Moving Coil?
Moving magnet and low-output moving coil cartridges require different amounts of gain and different electrical loading.
The Fono MM is intended for moving magnet cartridges and does not provide the additional gain or adjustable loading normally required by a low-output moving coil design.
Moving Magnet Cartridge
- Use the Rega Fono MM Mk5
- Typical output measured in several millivolts
- Standard 47 kilohm loading
- Suitable for Rega Carbon and Nd cartridges
Low-Output Moving Coil Cartridge
- Requires a suitable moving coil phono stage
- Needs substantially more gain
- May require resistance and capacitance adjustment
- Should not normally be connected to the Fono MM
How to Connect the Fono MM Mk5
- Switch off the turntable, Fono MM and amplifier.
- Connect the turntable's left and right RCA plugs to the Fono MM input.
- Connect a separate stereo RCA interconnect from the Fono MM output to a line input on the amplifier.
- Connect a separate turntable earth lead to the Fono earth terminal if the turntable provides one.
- Connect the Rega PS1 power supply to the rear AC socket.
- Turn the amplifier volume down.
- Switch on the Fono MM before switching on the amplifier.
- Select the amplifier input used by the Fono MM and gradually raise the volume.
Connect the Output to a Line Input
The output from the Fono MM must connect to a standard line-level amplifier input marked AUX, CD, Line, Tuner or similar.
Do not connect its output to another moving magnet or moving coil phono input. This would apply phono amplification and equalisation twice, resulting in severe overload and distortion.
Turntable Earthing
An earth terminal is provided on the rear panel for turntables or tonearms that use a separate signal-earth lead.
Connect the earth wire to this terminal if one is supplied with the turntable.
Many Rega turntables do not use a separate earth cable, so it is normal for the terminal to remain unused when the Fono MM is connected to a Rega deck.
If noticeable hum is present, check the RCA connections, cable routing, turntable earth arrangement and distance from nearby power supplies or transformers.
Powering the Fono MM
A front-panel button switches the phono stage on and off.
The Rega logo illuminates red when the unit is operating.
Rega recommends switching the Fono MM on before the partnering amplifier. A brief electrical surge during start-up could otherwise produce an audible thump through the loudspeakers.
Keep the amplifier volume low whenever the phono stage or its cables are being connected, disconnected or switched.
Positioning and Cable Routing
Place the Fono MM on a stable surface away from large mains transformers, wireless routers and high-current power supplies where possible.
Keep the low-level turntable cable away from mains leads and speaker cables, particularly where cables would otherwise run closely alongside one another.
If mains and signal cables must cross, arranging them at approximately a right angle can reduce the opportunity for induced hum.
Do not place the power adaptor directly beside the cartridge, tonearm base or turntable output cable.
Fono Mini, Fono MM or Aria?
Rega Fono Mini A2D
The
Rega Fono Mini A2D
is the more affordable moving magnet option.
It also includes a USB output for recording records to a compatible computer.
Choose it when budget or USB recording is the main priority.
Rega Fono MM Mk5
The Fono MM is a dedicated moving magnet stage without USB recording or cartridge-loading adjustments.
Its stronger circuit and power-supply arrangement make it the natural next step for a Planar 2, Planar 3 or another capable moving magnet turntable.
Rega Aria Mk3
The
Rega Aria Mk3
includes separate moving magnet and adjustable moving coil input circuits within a larger enclosure.
It is the higher-level option for more revealing systems or customers planning a future move from moving magnet to moving coil.
Is It an Upgrade Over a Built-In Phono Input?
The answer depends on the amplifier and the quality of its existing phono stage.
The Fono MM can be a worthwhile upgrade where the amplifier includes only a basic phono input or where the turntable is being connected to a line-only amplifier.
Separating the phono circuitry from the main amplifier also allows it to use a dedicated enclosure and power supply.
Some higher-level integrated amplifiers already include accomplished moving magnet stages, so a demonstration is the best way to assess whether the Fono MM provides a worthwhile improvement in a particular system.
Future Upgrade Path
The Fono MM can remain in the system while the turntable, stylus or moving magnet cartridge is upgraded.
A typical development path might include:
- Upgrade from a basic built-in phono input to the Fono MM Mk5.
- Improve the turntable support and setup.
- Upgrade a Rega Carbon stylus or move to an Nd cartridge.
- Add a Neo Mk2 power supply to a compatible Planar 3.
- Move later to an Aria or dedicated moving coil stage if changing to an MC cartridge.
What the Fono MM Mk5 Does Not Include
No Moving Coil Input
- No low-output moving coil gain setting
- No moving coil resistance adjustment
- No selectable moving coil capacitance
- Use a compatible MC phono stage instead
No Cartridge Adjustments
- Gain is fixed
- Input resistance is fixed
- Input capacitance is fixed
- Designed for straightforward moving magnet use
No USB Recording
- No analogue-to-digital converter
- No USB connection
- No computer-recording output
- Consider the Fono Mini A2D if USB is required
No Volume Control
- Not a conventional pre-amplifier
- Does not connect directly to passive speakers
- Listening volume is controlled by the amplifier
- No headphone output
Who Is the Rega Fono MM Mk5 For?
A Good Choice If You:
- Use a moving magnet cartridge
- Own a Rega Carbon, Nd3, Nd5 or Nd7
- Need to connect a turntable to a line-only amplifier
- Want to improve on a basic built-in phono stage
- Prefer simple fixed loading and gain
- Do not need USB recording
- Want a compact dedicated analogue component
- Own a Planar 1, Planar 2 or Planar 3 without a built-in phono stage
- Want an upgrade that can remain as the turntable develops
Consider Another Option If You:
- Use a conventional low-output moving coil cartridge
- Need adjustable gain or cartridge loading
- Want both MM and MC inputs in one product
- Need a USB output for recording vinyl
- Own a Planar 1 Plus with its internal phono stage
- Need balanced XLR outputs
- Want a built-in headphone amplifier
- Need remote control or automatic standby
Key Features
- Dedicated moving magnet phono stage
- Designed and made in England
- Fully discrete cascaded complementary input stage
- Two-stage RIAA equalisation
- Polyester capacitors within the signal path
- Polypropylene capacitors within the RIAA circuit
- Fixed 47 kilohm input loading
- Fixed 100pF input capacitance
- 41.4dB gain at 1kHz
- Compatible with Rega Carbon and Nd moving magnet cartridges
- Stereo RCA input
- Stereo RCA output
- Separate turntable earth terminal
- Front-panel power button
- Red illuminated Rega logo
- Compact aluminium case
- Matching design for the Neo Mk2 and Fono MC Mk4
- Simple fixed-gain operation
- Rega PS1 power supply
- Lifetime limited warranty against confirmed manufacturing defects
Included Accessories
- Rega Fono MM Mk5 Phono Stage
- Rega PS1 power supply
- User documentation
Frequently Asked Questions
What does the Rega Fono MM Mk5 do?
It amplifies the low-level signal from a moving magnet cartridge and applies the required RIAA equalisation before the signal reaches a normal amplifier line input.
Which cartridges can I use?
It is designed for moving magnet cartridges, including the Rega Carbon, Nd3, Nd5 and Nd7, as well as many conventional moving magnet designs using standard 47 kilohm loading.
Can I use it with a moving coil cartridge?
It is not suitable for conventional low-output moving coil cartridges. These require a compatible moving coil stage such as the Rega Fono MC Mk4, Aos MC, Aria Mk3 or Aura.
Does it have adjustable gain?
No. Gain is fixed at 41.4dB, making the unit simple to install with a suitable moving magnet cartridge.
Can the cartridge loading be adjusted?
No. Input loading is fixed at 47 kilohms in parallel with 100pF.
Where does the turntable connect?
Connect the turntable RCA plugs to the input sockets on the rear of the Fono MM.
Where does the Fono MM output connect?
Connect it to a normal line-level amplifier input marked AUX, CD, Line, Tuner or similar.
Can I connect it to the Phono input on my amplifier?
No. Connecting one phono stage to another will cause excessive gain, incorrect equalisation and severe distortion.
Can I use it if my amplifier already has a phono input?
Yes. Connect the Fono MM to one of the amplifier's spare line inputs and compare it with the built-in phono stage.
Does it work with the Rega Planar 1?
Yes. The standard Planar 1 has a Carbon moving magnet cartridge and phono-level output suitable for the Fono MM.
Does it work with the Rega Planar 1 Plus?
No. The Planar 1 Plus already contains its own phono stage and provides a line-level output.
Does it work with the Rega Planar 3?
Yes. It is a natural partner for a Planar 3 fitted with an Nd3, Nd5 or another suitable moving magnet cartridge.
Can it be used with an Nd7?
Yes. The Nd7 is a moving magnet cartridge and is compatible with the Fono MM Mk5.
Do I need to use the earth terminal?
Use it if your turntable or tonearm has a separate earth lead. Many Rega turntables do not require a separate earth connection.
What should I do if the system hums?
Check the RCA plugs, any separate earth lead, cable routing and the distance between the turntable or Fono MM and nearby mains transformers or power adaptors.
Which component should I switch on first?
Rega advises switching on the Fono MM first and then the amplifier, with the amplifier volume turned down.
Does it have USB recording?
No. Consider the Rega Fono Mini A2D if a USB output for recording records to a computer is required.
Does it have a volume control?
No. Listening volume is controlled by the connected amplifier or pre-amplifier.
Does it have a headphone output?
No. Headphones must connect to the amplifier or a separate headphone amplifier.
Is the power supply included?
Yes. The Fono MM is supplied with the appropriate Rega PS1 power supply.
Can Audio T help compare it with my amplifier's phono input?
Yes. Contact your local Audio T store to arrange a demonstration and discuss your turntable, cartridge and amplifier.
Why Buy From Audio T?
- Specialist advice from experienced in-store teams
- Help confirming moving magnet cartridge compatibility
- Demonstrations against suitable built-in and external phono stages
- Rega Carbon and Nd cartridge matching advice
- Help comparing the Fono Mini, Fono MM, Fono MC and Aria
- Turntable setup, cartridge alignment and tracking-force support
- Advice on earthing, cable routing and reducing system hum
- Planar 1, Planar 2 and Planar 3 upgrade guidance
- Part exchange available on suitable equipment
- Ongoing support from the UK's oldest independent specialist Hi-Fi retailer
Contact your local Audio T store
to arrange a demonstration or discuss whether the Rega Fono MM Mk5 is right for your turntable and cartridge.