Whether you’re brand new to the world of hifi, or you’re a longtime audiophile, it’s always helpful to get a refresher on how to improve your sound. There are so many delicate moving parts that make music play out of a phonograph, and paying attention to each of them only improves your listening experience. The more you learn about the science of sound, the more satisfying it feels to curate a space dedicated to top-notch acoustics. As with all things audio, the key to perfect playback is a combination of attention, high-quality gear, and energy to rearrange your set-up if needed.


Since it’s natural to primarily focus on the quality of your stylus and turntable cartridge, it can be all too easy to skip over other important parts of the record player. A turntable ground wire might not be as sexy as other pieces of equipment, but it can play a major role in improving playback. Luckily, once you learn how to locate it, and what precisely it does, connecting your turntable ground wire is easy and makes an immediate difference.


What is a turntable ground wire?

First things first: what precisely is a turntable ground wire? A grounding wire is a single wire you can attach to your turntable chassis and amplifier. This wire puts the turntable and the amplifier at the same ground potential (the zero reference level used to apply and measure voltages, in this case in the context of sound). If you don’t ground a turntable, a small difference in ground potential will cause a ground loop. A ground loop could then cause a 60-cycle alternating current to pass between a turntable and amplifier along your audio cables. Since preamplifiers for phono inputs are deeply sensitive, you can hear an audible 60-cycle hum with the phono input selected. In layman’s terms, a ground cable can help you avoid humming and improve your overall sound quality. Luckily, many turntables come with a grounding wire, so you generally don’t have to seek them out.


Why do you need a ground wire?

You may agree that excess hum isn’t ideal, but this still begs the question of how exactly a ground connection mitigates unwanted sound. Why don’t the other cables involved in the connection between an amplifier and a turntable have these bases covered? Basically, grounding wires create an alternate path for the electrical current to flow back to the source, rather than creating excess noise or a potentially dangerous electric charge. While the other cables are meant to carry the sound from the source to the amps (and eventually the speakers), a grounding wire’s whole job is to only pick up what’s extra. A grounding wire is a safety wire that has intentionally been connected to earth, and does not carry electricity under normal circuit operations. It’s almost like a bucket picking up the spare water so a room doesn’t flood, except instead of mitigating water it’s scooping up electrical current that could cause excess hum or charge. 


How do you know if hum is because of a grounding loop?

While an ungrounded turntable usually causes hum, that’s not the only reason for noise. So it can save you time to make sure you’re fixing the right problem. A record player’s hum is generally caused by one of two factors: feedback or a grounding loop. A ground loop hum is 120 hertz, while other hum will be 60 hertz. This may sound overly technical, but there are easy ways for the untrained ear to figure out which hum it is. First of all, the sound itself is vastly different. The 120 hertz hum will sound aggressive and high-pitched, while 60 hertz hum is lower and more even. 


Another way to differentiate the source of hum is to turn the volume knob and see if the hum follows. If the hum goes down with the volume, this generally means it’s from feedback or an issue other than ground looping. Also, if you change inputs and the hum doesn’t change or stop, that’s likely a grounding loop.


If you discover the hum isn’t a grounding loop, there are a few things you can immediately check for a possible solution. The first is very simple, but easy to lose sight of: make sure your turntable is on a completely flat and sturdy surface. Secondly, make sure your speakers aren’t on the same surface as the record player, since even subtle vibrations can cause a feedback loop. Third, make sure the phonograph isn’t kept near any sources of static.


Is it always necessary to ground my turntable?

Usually, yes. Regardless of whether it’s a belt or direct drive turntable, there’s a potential for ground loop. Since the ground wire doesn’t conduct the electrical currents for the music itself, you don’t technically need to ground a record player in order to listen to music. However, even if the hum isn’t super noticeable, in most cases it’s better to play it safe to avoid a ground loop. If your turntable comes with a ground wire, that’s a surefire sign it needs to be grounded. Technically, some turntables with built-in phono preamps don’t require grounding. If your turntable has a built-in phono preamp that you use instead of a separate, there’s no grounding wire included, and you’ve never had sound issues – you may be fine. It’s easy enough to check for a wire, and also see what the sound is like. Even so, it never hurts to ground it.


Do I need to ground RCA cables?

The short answer is no. RCA cables are already balanced and grounded by nature of their design. The three-wire cable includes two signal wires and one ground wire, all of which are sheathed in a cylindrical shield that is also grounded. The two signal wires have identical impedances to the common ground terminal, so they are generally immune to creating hum. 


How do I find the grounding wire?

You’ll want to look on the bottom of your record player to find it. Many times, the grounding wire is  connected to the underside of the metal turntable chassis and has an unconnected copper spade connector. Most classic turntable ground wires are green, although they could technically come in any color. If your turntable is brand new, the wire might be folded up underneath the chassis and concealed with a twist tie. Make sure you’ve fully checked the underside of the chassis before concluding you don’t have one.


Can I use speaker wires if I don’t have a grounding wire?

Yes. The main objective of a grounding wire is to connect to the earth and provide a wire that doesn’t carry its own signal. Technically, any insulated wire can do the job, ideally 18 to 20 gauge stranded wire. You just have to make sure to properly connect it to the amplifier’s grounding terminal, or create a connection using gaffer tape.


How do I ground my turntable?

All this talk about why it’s important to ground a turntable still leaves the “how’ question looming in the air. The first thing you’ll want to do is turn off your turntable and amplifier. You don’t want to run the risk of electric shock or unseemly noise. Next, you’ll check under the metal chassis to locate your grounding wire. If your turntable doesn’t include one, then pick out the insulated wire you’re going to use. Once you have the wire on hand, you’ll want to find the grounding terminal on your amplifier or receiver. Usually, the terminal can be found on the back of the unit under the marking “grounded.” Oftentimes, it’s a metal post with a simple screw terminal or a metal post with a knurled shaft. Make sure to loosen the grounding terminal once you’ve located it. 


Double-check to ensure the grounding wire can reach your amplifier’s grounding terminal. If it can’t, move equipment as needed (or measure and cut your own grounding wire according to this distance). Now, all you have to do is slip the ground wire spade connector onto the grounding terminal. Make sure it’s tightened enough to be sturdy, but don’t overtighten. 


If your amplifier doesn’t have a grounding terminal, have no fear. You can use gaffer tape to stick the grounding wire’s copper spade connector onto the amp’s metal box. Just make sure you secure it enough so that it won’t disconnect.


If you end up making your own grounding wire, you’ll want to strip roughly 6 to 8 mm of insulation from both ends of the wire. Then, you’ll attach one stripped end to the chassis screw on the amplifier (try to avoid the speaker terminal). You’ll attach the other stripped end of wire to the chassis screw on the turntable. This set-up creates the same basic effect as a grounding terminal. 


Once the amp and turntable are connected, you should be able to turn on the record player and test it out to see if the hum is gone. If the sound is clear and gorgeous, your work here is done.