A phono preamp, also called a phono stage, is the part of a vinyl playback system that prepares the very small signal from a turntable cartridge for an amplifier or active speaker system.
Some turntables, amplifiers and powered speakers already include a phono preamp. Others do not. Understanding where the phono stage sits in the signal chain is one of the easiest ways to avoid a system that sounds extremely quiet, thin or distorted.
What Is a Phono Preamp?
A phono preamp is a specialised preamplifier designed for the electrical signal produced by a turntable cartridge. A cartridge generates a much lower output than typical line-level sources such as a streamer, DAC or CD player.
The phono stage increases that signal to a usable level and applies the equalisation required for vinyl playback.
Why Does a Turntable Need a Phono Preamp?
Vinyl records are cut using an equalisation curve that reduces low frequencies and increases high frequencies during mastering. This allows grooves to be cut more efficiently and reduces some practical limitations of the physical format.
During playback, a phono preamp applies the complementary RIAA equalisation curve while also adding gain. Without this process, the signal will not have the correct tonal balance or level.
Phono Level vs Line Level
A turntable cartridge normally produces a phono-level signal. Most standard amplifier inputs expect a much stronger line-level signal.
This means that connecting a turntable directly to a normal AUX, LINE or similar input without a phono stage can result in extremely low volume and incorrect frequency balance.
Once the phono preamp has processed the signal, it can be sent to a standard line-level input.
Where Can the Phono Preamp Be Located?
Built Into the Turntable
Some turntables include an internal phono preamp. These models may provide a line-level output that can connect directly to a normal amplifier or powered speakers.
Built Into an Amplifier or Receiver
Many integrated amplifiers and receivers include a dedicated input labelled PHONO. In this case, the phono preamp is inside the amplifier.
External Phono Preamp
An external phono preamp is a separate component placed between the turntable and amplifier. This arrangement allows the listener to choose a phono stage that matches the cartridge and the rest of the audio system.
How Do I Know If I Need a Phono Preamp?
Check the specifications of both your turntable and amplifier. If the turntable outputs a phono-level signal and the amplifier does not have a PHONO input, you need an external phono preamp.
If the turntable has a switch labelled PHONO/LINE or a built-in phono stage, you may be able to connect it directly to a line input when LINE mode is selected.
If your amplifier has a dedicated PHONO input that is compatible with your cartridge, an additional external phono preamp is usually not required.
Moving Magnet vs Moving Coil Phono Preamps
Moving magnet (MM) and moving coil (MC) cartridges can have different output levels and electrical loading requirements.
Many phono stages support MM cartridges, while some also provide dedicated MC settings with additional gain and different loading options.
Before connecting a cartridge, check that the phono preamp supports the cartridge type and the manufacturer's recommended settings.
Can I Use Two Phono Preamps?
You generally should not run the signal through two active phono stages. For example, if a turntable's internal phono preamp is enabled, its line-level output should normally connect to a standard line input rather than another PHONO input.
Using two phono stages can create excessive gain, incorrect equalisation and distortion.
Typical Turntable Signal Chains
Turntable to Amplifier With a Phono Input
Turntable → PHONO input → amplifier → speakers
Turntable With External Phono Preamp
Turntable → external phono preamp → LINE/AUX input → amplifier → speakers
Turntable to Powered Speakers
Turntable → phono preamp → powered speakers
If either the turntable or powered speakers already include the correct phono stage, the exact chain may be different.
What Makes a Good Phono Preamp?
A phono preamp should provide appropriate gain, low noise, accurate equalisation and electrical compatibility with the cartridge.
For more advanced systems, useful features can include adjustable gain, capacitance, resistance loading or separate MM and MC modes.
Price alone does not determine whether a phono stage is appropriate. Matching it to the cartridge and system is more important.
Hum and Noise in a Phono System
Because cartridge signals are small, phono systems are more sensitive to grounding and electromagnetic noise than many line-level sources.
If you hear hum, check the turntable ground connection when one is required, keep signal cables away from power supplies and verify that every connector is fully seated.
A problem should be diagnosed systematically rather than simply adding more gain.
Does a High-End Turntable Need a High-End Phono Preamp?
A revealing turntable and cartridge can benefit from a phono stage that provides appropriate gain, low noise and good electrical matching. However, there is no universal price ratio that must be followed.
The turntable, cartridge, phono preamp, amplifier and speakers work as one system. Improvements are most useful when the components are compatible and correctly configured.
Frequently Asked Questions
Is a phono preamp the same as a preamp?
No. A phono preamp is specifically designed for turntable cartridge signals and RIAA equalisation. A conventional line preamp works with already amplified line-level sources.
Do all turntables need a phono preamp?
Vinyl playback requires a phono stage somewhere in the signal chain, but it may already be built into the turntable, amplifier, receiver or powered speaker system.
Can I connect a turntable to AUX?
Yes, if the signal has already passed through a phono preamp and is at line level. A raw phono-level signal should not normally be connected directly to AUX.
What does PHONO mean on an amplifier?
It indicates an input that includes a phono preamp designed for a turntable cartridge. Check whether it supports MM, MC or both.
Final Thoughts
A phono preamp is the bridge between the tiny electrical signal produced by a cartridge and the line-level world of amplifiers and powered speakers.
Once you understand whether the phono stage is inside the turntable, amplifier or a separate box, building a vinyl system becomes much easier. For the rest of the playback chain, see our complete guide to turntables and record players.