You need a phono preamp only when neither your turntable nor your amplifier has one built in. A turntable’s cartridge produces a very weak signal that has to be boosted and corrected before an ordinary amplifier or speaker can use it. Many turntables, amplifiers and Bluetooth turntables now do that job inside, in which case you do not need a separate box.
What is a phono preamp?
A phono preamp, also called a phono stage, sits between the turntable and the amplifier. It does two jobs.
The first is to boost the signal. A cartridge makes sound by moving a tiny magnet or coil as the stylus traces the groove, and the signal it produces is far weaker than the output of a CD player, a TV or a phone. Without extra gain, a turntable connected to a normal input sounds very quiet and thin.
The second job is equalisation. When records are cut, the bass is reduced and the treble is boosted, following a standard curve called RIAA. This keeps the groove a manageable size and helps reduce surface noise. The phono preamp applies the opposite curve on playback, so the bass comes back and the treble returns to normal.
When do you need a separate phono preamp?
You need one if both of these are true:
Your turntable has no built-in preamp. Many traditional turntables send out the raw cartridge signal only.
Your amplifier or powered speakers have no phono input. Look for an input marked PHONO, often with a small earth terminal beside it.
In that case the turntable cannot connect straight to a line-level input such as AUX or CD. A separate phono preamp goes in the middle and turns the signal into something the amplifier can use.
Powered speakers work the same way. Many have line-level inputs only, so a turntable without its own preamp needs one in between. Our guide to powered vs passive speakers explains where the amplifier sits in each kind of system.
When do you not need one?
You can skip a separate unit when any of these applies:
Your amplifier has a phono input. Connect the turntable there and the amplifier does the work.
Your turntable has a built-in preamp. Switch it on and connect the turntable to any line-level input.
You use a Bluetooth turntable. The signal is boosted and equalised inside the turntable before it is sent to your speakers, so there is nothing extra to add.
Our guide to whether record players need speakers explains how these pieces fit together in a complete system.
What is the two preamps mistake?
It is the most common setup problem with turntables. If the turntable’s built-in preamp is switched on and you connect it to a PHONO input, the signal is boosted and equalised twice. The result is loud, distorted and very heavy in the bass.
The opposite mistake sounds the other way. If the built-in preamp is switched off and you connect the turntable to a line input such as AUX, there is no boost and no equalisation, so the music is faint, thin and tinny.
The rule is simple: one phono stage in the chain, never two and never none. If your turntable has a switch on the back, set it to match the input you are using.
Does a separate phono preamp sound better?
It can, but it depends on the rest of the system. A good standalone phono stage can be quieter and more detailed than the one built into a budget amplifier. A well-designed built-in stage, though, does the job properly for most listeners. If you use a moving coil cartridge, check that your preamp supports it, because moving coil types produce an even weaker signal and need more gain.
If you are deciding between streaming and a wired setup, our guide to whether Bluetooth turntables sound as good as wired ones compares the two.
Do uStream turntables need a phono preamp?
No. The uStream TT1 is a Bluetooth turntable with a built-in phono preamp and a built-in RIAA equaliser, and it uses an Audio-Technica AT-3600 moving magnet cartridge. It streams over Bluetooth 5.1 to any Bluetooth speaker, including every uStream speaker. The preamp is switchable by a rear slide switch, so you can also use its RCA left and right outputs with your own amplifier or phono stage. The uStream Groove, a complete wireless stereo system for your records, builds the same turntable into a system whose speakers pair with it automatically.
Frequently asked questions
How do I know if my turntable has a built-in preamp?
Look for a switch on the back marked PHONO and LINE, or check the specifications. Bluetooth turntables and many modern turntables include one.
Can I connect a turntable straight to powered speakers?
Yes, if the turntable has a built-in preamp switched on, or the speakers have a phono input. Otherwise you need a phono preamp in between.
What happens if I use two phono preamps?
The signal is boosted and equalised twice, so it sounds loud, distorted and boomy. Switch one of them off.
Is a phono stage the same as a phono preamp?
Yes. Phono stage, phono preamp and phono preamplifier all describe the same thing.
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