Signal-to-Noise Ratio on Turntables: What the Number Means

What Is Signal-to-Noise Ratio?

Signal-to-noise ratio, often abbreviated S/N or SNR, is a specification that describes how much unwanted noise is present relative to the audio signal your turntable produces. It is measured in decibels (dB). A higher S/N value indicates a greater difference between the music and the noise floor, meaning that the background hiss, hum, or other artifacts are less audible.

In practical terms, when you play a vinyl record, the cartridge and phono preamp amplify both the musical signal and any noise picked up from the stylus, tonearm, motor, or electrical interference. S/N tells you how loud that noise is compared to the music. A turntable with a high S/N will let you hear quiet passages without a distracting layer of noise.

How S/N Is Measured on a Turntable

Manufacturers measure S/N by playing a test tone from a test record and measuring the output level through the phono preamp. They then measure the noise floor when no signal is present, or when the stylus is playing a silent groove. The difference between these two levels, expressed in dB, is the S/N ratio.

The measurement includes all noise sources in the signal chain: the cartridge, the tonearm wiring, the internal or external phono preamp, and any electromagnetic interference. It does not include noise from the recording itself, such as surface noise from dust or scratches. That is why S/N is a useful spec for comparing the electrical performance of different turntables, independent of the condition of your records.

S/N vs. Rumble: What’s the Difference?

Rumble is a specific type of noise that originates from the mechanical parts of the turntable: the motor, bearings, and platter. It is generally low-frequency, and you might hear it as a low hum or rumble, especially in quiet passages. Rumble is measured separately and expressed in dB relative to the signal, usually as a negative number.

S/N, on the other hand, is a more comprehensive specification. It includes rumble, but it also covers hiss from the electronics, hum from power supplies, and any other noise that appears at the output. So when you see a S/N spec, it tells you how quiet the entire playback chain is, not just one component. A turntable can have a good rumble spec but a mediocre S/N if its phono preamp is noisy. For a deeper dive into rumble itself, see our article on the turntable rumble spec.

Why Signal-to-Noise Ratio Matters

The S/N ratio becomes most noticeable in quiet musical passages. When the music is soft, the noise floor becomes more apparent, and a low S/N can make the record sound muddy or distracting. In a quiet room, even a small amount of hiss or rumble can be audible.

A good S/N also matters when you use a loud volume setting or connect to high-sensitivity speakers. The noise will scale with the music, so a turntable with a poor S/N can ruin an otherwise good system. For critical listening, a high S/N is more important than for background music in a busy room.

The Role of the Phono Preamp

The phono preamp is a critical link in the chain. It amplifies the tiny signal from the cartridge to line level. A noisy preamp can degrade the overall S/N even if the turntable itself is quiet. So when comparing turntables, pay attention to the quality of the built-in phono stage if you plan to use it.

If you choose to connect the turntable to an external phono preamp, you get more control over the signal path, and you may achieve a higher S/N if the external unit is of better quality. However, the overall S/N will be limited by the noisiest component in the chain. See our guide on phono preamps for more.

How to Evaluate S/N When Buying a Turntable

When you compare turntables, look at the S/N spec in the manufacturer’s documentation. A higher number is better, but keep in mind that different manufacturers may measure S/N under different conditions, so it’s not always directly comparable. Still, it gives you a general idea of the electrical noise performance.

Also consider other specs like channel separation, frequency response, and wow and flutter. A turntable with a high S/N but poor channel separation may not sound as good as one with balanced specs. For guidance, our best turntables under 300 and best turntables under 500 lists compare these specs across models.

Keep in mind that S/N is measured with a specific cartridge and preamp. If you later upgrade your cartridge, the actual S/N may change. Look for specs that are measured with the included cartridge, and read our guide on cartridge upgrade to understand how that affects performance.

How to Improve Your Turntable’s Signal-to-Noise Ratio

Even if your turntable has a modest S/N, you can reduce noise by taking care of your records and playback environment. The Library of Congress recommends using canned air to blow away dust from grooved discs, which helps minimize surface noise that adds to the noise floor.

Grounding your turntable properly can eliminate hum. You can find steps in our guide on grounding. Also, placing the turntable on a stable, vibration-isolated surface reduces mechanical noise that can be picked up by the stylus. See turntable isolation. Finally, make sure the stylus is clean and in good condition, as a worn stylus can inject noise. Our cleaning guide covers this.

What to pick for your use

Questions

What is a good signal-to-noise ratio on a turntable?

A good S/N ratio depends on your listening environment and system. In general, a higher ratio is better, but you should also consider other specs. For a quiet room, aim for a model that emphasizes low noise in its specifications.

Does signal-to-noise ratio affect Bluetooth streaming?

When you connect a turntable to a Bluetooth speaker or receiver, the S/N of the turntable still matters because the Bluetooth transmitter sends the analog signal after it is processed. The Bluetooth link itself does not improve or degrade the S/N; it simply transmits what it receives.

How is S/N different from rumble?

Rumble is a low-frequency noise from the turntable's mechanical parts, while S/N covers all noise including hum, hiss, and rumble. S/N is a broader measurement of the entire playback chain's noise performance.

Can I improve the S/N of my existing turntable?

Yes, you can reduce noise by cleaning your records, grounding the turntable properly, isolating it from vibrations, and keeping the stylus clean. These steps lower the noise floor, effectively improving the S/N you experience.

Why do some turntables not list S/N?

Some manufacturers omit S/N from their specs, especially budget models. You can still evaluate noise performance by reading reviews or comparing other specs like rumble and the quality of the phono preamp.

Does the condition of my records affect S/N?

Yes, surface noise from dust and scratches adds to the noise floor. The Library of Congress recommends using canned air to remove dust from records. This reduces the noise you hear, effectively improving the perceived S/N.