Can you hear an annoying hum coming from your record player? A lack of proper grounding probably causes that.
This article demonstrates how to ground a turntable and explains why it is important.
Often overlooked, grounding electrical equipment is an essential stage in any turntable setup process.
There are several reasons why you need to ground your turntable to the rest of your audio equipment.
The primary purpose of grounding is to prevent the hum and audio interference caused by the undesirable phenomenon called a ground loop. This annoying hum will ruin a listening experience and gets really tiring on your ears.
Whether you’re using a new turntable or one that is decades old, you will need to check the grounding connection.
A ground loop is caused when the chassis connections of multiple electronic devices don’t share the same ground potential. It means the electronic current is not terminating properly, so energy is moving around the device, which causes noise.
Grounding a turntable helps to improve the sound quality of your audio system by removing unwanted interference noise. When grounded correctly, even an untrained ear will notice an immediate difference.
If you want your records and audio gear to sound good whilst you listen to it, then yes, you will need to ground your turntable setup properly.
It doesn’t matter what kind of turntable you’re using – whether it’s a belt or direct drive, it will need grounding to prevent ground loops from forming.
The hum caused by a lack of grounding can be pretty unbearable, and the only way to remove it is by grounding the deck. Luckily it’s an easy process that can be completed in a few minutes.
This guide details the basic process for grounding a turntable. This example demonstrates using a turntable that has built-in grounding terminals. If yours doesn’t have these, then check out the next section for some tips.
Before getting started, read through the steps and get a deep understanding of the completed process. This way, you can prepare for the process and check that you have all the necessary materials and tools.
To prevent any damaging noises or dangerous accidents, you should turn off the power of your audio setup.
This will include the turntable, amp, speakers, and anything else plugged in. This mitigates the chance that you could cause dangerously loud noises when changing connections.
There isn’t much risk of electric shock in this process, but it also helps to prevent that risk too.
First, you need to find the grounding terminal of the turntable. Some turntables come with a grounding wire; others come with a simple terminal post, which is easily paired with an unconnected copper spade connector.
These parts are usually at the back of the turntable or under its base. They are usually marked with “earth/ground” or the following icon.
Some turntables come with an earth or ground wire, pre-attached, which makes the process a little quicker. Sometimes on new turntables the wire is hidden below the base, wrapped with a twist tie.
However, often you will need to make your own grounding wire and attach it yourself.
If your turntable doesn’t have a ground wire, follow these steps.
If you want to improve the quality of the wire, you can attach an unconnected copper spade connector to either end of the cable.
After you have found/attached the grounding wire to the turntable, it’s time to connect it to the amplifier’s grounding terminal.
Find the ground terminal on your amplifier. Again, these are usually on the back and will be marked with a grounding indicator. Often you can find them next to the amp’s phono input.
Some devices use a simple screw terminal; others use a different mechanism.
Some amps may feature a wire rather than a terminal. In this case, you must connect the two wires between the amp and the turntable.
If your amp doesn’t have a grounding terminal, you can connect it to the metal chassis, although I’ll explain this in more depth later.
Once found, all you need to do is attach the turntable ground wire to the amp’s grounding terminal.
You want to make sure the cable isn’t too tight either, as this makes it easy for the earth to disconnect. This is why you should use a longer cable with room for slack.
Some turntables feature a ground wire spade connector. These make it easier to attach the wire to the terminal and look like this. You can also find RCA cables with his connector attached.
Now it’s time to test it out. Turn on your turntable, amp, and speakers. Even without playing a record, you can hear the results.
Start by setting the volume knob to zero, turn on your rig, then slowly turn the volume up. If you did everything right, your speakers should basically be silent.
If there are still problems, then you will hear ground hum interference, and you will need to try the process again or troubleshoot for issues.
It’s pretty easy to test out whether your turntable is grounded. The main way of testing is to power up your rig and listen for any ground looping noise interference.
Don’t worry if either your amp or turntable doesn’t have a grounding wire or terminal, some workarounds can be used to earth them together.
A lot of beginner turntables + amps don’t have grounding terminals, in which case there’s a method to use chassis screws on the back of both devices to connect a wire manually.
If the deck has a terminal but no wire, follow the instructions in step 2b above.
If your turntable has neither a ground terminal nor a wire, then you will need to improvise one – described below.
Cut and measure a wire as described in step 2b above. Now, because there is no grounding terminal on the deck, you will need to attach the turntable ground wire directly to the chassis.
Once the cable is attached to the amp, you can touch the other end to various parts of the turntable chassis, listening for improved sound quality. Use this technique to find a good spot to tape the cable to the metal turntable chassis.
The same goes for amplifiers that are missing a ground connection. Whilst most will have one, not all do, and sometimes they break. In this case, you can attach the wire to a chassis screw of your amplifier rather than a speaker terminal.
Last Resort – in countries with three-pin sockets, just hooking up a wire to the earth pin of an otherwise empty plug connected to the turntable can also do the trick. (This is tried and tested – although it may sound risky, it is safe if done properly.)
Instead of producing additional noise or a possibly harmful electric charge, grounding wires provide an alternate way for electrical current to return to the source.
While the other cables are designed to transport the audio signal from the deck to the amp and speakers, a grounding wire’s only purpose is to earth the electronic circuit.
A grounding wire is linked to the earth and does not carry electricity during normal circuit functioning. It’s basically an ‘escape route’ for extra unused electrical current. Without proper grounding, a “ground loop” is created that builds up and creates a hum.
To stop turntable hum, you need to identify the root of the issue first. There are a few areas where hum can arise in a turntable. First, check the grounding wire and make sure it is correctly attached to the amp.
If it appears to be a grounding issue, then follow the steps above to connect it.
Another common area for issues is the audio cables themselves. Sometimes they can break or become disconnected, which can cause a hum with the audio signal. This is easily fixed by replacing or reconnecting them.
A feedback loop can also cause hum if your turntable is too close to your speakers. Always avoid placing your record player and speakers on the same surface. In this case, simply move the turntable further away, or install it on a vibration-isolating stand.
A final area to check is the connection between the cartridge and the tonearm. Sometimes the connection becomes loose, and you will need to tighten the tonearm’s cartridge holder/screw to make sure the cartridge is connected properly.
Other suspects include a damaged stylus or phono cartridge or an incorrectly adjusted tracking force.
You can tell if turntable hum is due to a grounding loop by the frequency of the sound The ground loop hum has a frequency of 120 Hertz, whereas the rest hum has a frequency of 60 Hertz. It may sound complicated, but even a beginner listener can figure it out.
To begin with, the noises are vastly different.
A 60-Hertz hum will be low and irregular, but a 120-Hertz hum will be forceful and higher pitched.
Another technique to distinguish the origins of the hum is to adjust the volume and see how the hum responds.
If you think the hum may be coming from somewhere other than your record player, disconnect all your inputs from the amp, turn up the speakers, and listen for any noise. If the hum is still there, the issue will be with the rest of the gear other than your record player.
Turntable grounding wires are simple copper wires with spade connectors attached on both ends, most commonly. Sometimes they come pre-attached to your turntable.
Their function is to help prevent so-called ground loops, that can cause annoying turntable hum.
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I'm a passionate vinyl collector, analog fan, and lifetime enthusiast of most things audio.
On VinyliQ I help fellow vinyl collectors enjoy their hobby to the max, sharing my knowledge about and passion for vinyl.