So what is a Phono Preamplifier?
Vinyl lovers everywhere have been riding high on the revival of the turntable/record player which in turn throws a small spotlight back on the humble phono stage. Read on to find out why adding a phono stage to your set up could help you get more from your vinyl.
A phono preamplifier (also known as a phono stage) provides the connection between the turntable/record player and your amplifier. When vinyl was the defacto standard for audio recording, the phono stage was built-in to all receivers and amplifiers allowing direct connection of a turntable. However, as new formats like CDs were introduced and begun to replace vinyl, manufacturers of amplifiers removed or reduced the quality of their built-in phono stages and inputs as they were no longer being used.
Even today a lot of hi-fi amplifiers still won’t let you connect a turntable directly. You need to connect via a phono preamplifier to make the very low-level signal from the turntable's phono cartridge powerful enough for your main amp to work with it.
How does a Phono Preamplifier work?
To connect a turntable to an amplifier or receiver you will need to "pass" the signal through an external phono pre-amplifier to increase the level to match your amplifier/receiver auxiliary input.
Turntables cartridges output a very small signal (measured in milliwatts) and this needs amplifying up to several hundred times before it is loud enough for your amplifier. If any noise creeps in before or during amplification, it will become increased in volume detracting from the potential audio quality.
Good quality dedicated phono preamplifiers are fine tuned to reproduce the warm sound of vinyl, free from hiss or bearing rumble thanks to the engineer’s expertise in circuit design, component choice and layout.
Connected using a single pair of audio interconnect cables, a phono preamplifier is set-up in seconds allowing you to appreciate stunning clarity, musicality and resolution from all your vinyl recordings
Do I really need a separate Phono Stage?
Some amplifiers do have a phono input, but the mass-market models as well as home theatre receivers are massively out-performed by external phono preamplifiers. Vinyl lovers will instantly hear the difference that a dedicated phono preamplifier makes to music quality and especially so if they have invested in a decent player and some modern recordings.
What's Moving Magnet and Moving Coil?
A phono cartridge has a number of main components, the stylus (comprised of a cantilever with a diamond tip), a magnet and a coil. As the coil or magnet move in relation to each other they generate a voltage. The primary difference between the cartridge types is, Moving Coil cartridges have a much lower output voltage compared to Moving Magnet cartridges, so require a higher level of amplification before input to your amp. This means your choice of phono preamplifier will depend on which type of cartridge you choose.
Moving Magnet Cartridge
In the simplest terms, Moving Magnet (MM) cartridges, are exactly what they sounds like. A magnet is attached to the end of the cantilever which moves in relationship to a coil of wire which induces a voltage of around 5mV. This example shows the basics of how a moving magnet cartridge works.
Moving Coil Cartridge
Moving Coil (MC) cartridges have the same basic components but the opposite way around. A coil is attached to the end of the cantilever which moves in relationship to a magnet inside the cartridge which induces a much smaller voltage of around 0.5mV. Due to the smaller parts and greater precision, moving coil cartridges tend to be expensive compared to a moving magnet cartridge. This example shows the basics of how a moving coil cartridge works.