Why a Phono Preamp Is Required for a Turntable
A turntable cartridge produces an extremely low-level electrical signal that cannot be connected directly to a standard amplifier input. The phono preamp performs two essential functions: it amplifies the cartridge signal to line level and applies the RIAA equalisation required for accurate vinyl playback.
Without a phono stage the audio signal from a record player would be extremely quiet and the frequency balance would be incorrect because the RIAA playback curve would not be applied.
In a typical vinyl playback system the signal path follows this structure:
turntable → phono preamp → amplifier → speakers
Some integrated amplifiers include a built-in phono stage, while many hi-fi systems use a dedicated external phono preamp for improved signal quality and compatibility with a wider range of cartridges.
Phono Preamps for Moving Magnet and Moving Coil Cartridges
Phono preamps are designed to match specific cartridge types, most commonly Moving Magnet (MM) and Moving Coil (MC) cartridges. Each cartridge design produces a different output level and requires different gain and electrical loading in order to reproduce the recorded signal accurately.
Moving Magnet cartridges typically produce higher output levels and require less gain from the phono stage. Moving Coil cartridges generate much lower signal levels and therefore require additional amplification and precise loading to maintain correct frequency response and low noise.
Many modern phono preamps support both cartridge types, allowing the gain and loading to be adjusted to suit the cartridge installed on the turntable. Some designs are optimised specifically for MM or MC cartridges depending on the intended hi-fi system configuration.
RIAA Equalisation and Signal Processing
During vinyl record mastering the audio signal is recorded using the RIAA equalisation curve, which reduces low frequencies and boosts high frequencies. This process allows records to be cut more efficiently and reduces groove distortion.
A phono preamp reverses this process during playback by applying the inverse RIAA curve. This restores the original tonal balance of the recording and ensures accurate frequency reproduction from the record.
Because phono cartridges generate signals measured in millivolts, the phono stage must also provide precise gain while maintaining a low noise floor. High-quality phono preamps carefully control gain, impedance and capacitance loading to ensure stable operation with a wide range of cartridges.
Choosing a Phono Preamp
Selecting a phono preamp depends on several factors within a hi-fi system.
Cartridge compatibility is the most important consideration. The phono stage must support the gain requirements and electrical loading needed by the cartridge installed on the turntable.
System layout is also important. Some systems rely on a phono input built into the amplifier, while others use an external phono stage to achieve greater control over cartridge matching and signal performance.
Standalone phono preamps are often chosen by vinyl listeners who want to optimise the performance of their turntable and cartridge combination while maintaining flexibility for future upgrades.
Phono Preamps at The Groove Man
The Groove Man offers a carefully selected range of phono preamps and phono stages designed for modern vinyl playback systems. Our collection includes phono stages compatible with both Moving Magnet and Moving Coil cartridges, supporting a wide range of turntables and hi-fi amplifiers.
From our Brisbane location we supply turntable electronics and hi-fi components to customers across Australia who are building or upgrading dedicated vinyl playback systems.
