One of the leading causes of unpleasant sounds and distortion in audio equipment is grounding issues. When multiple pieces of equipment’s connections are at different ground potentials or voltages, an undesirable effect known as the “ground loop” phenomenon occurs.
For instance, a turntable must be adequately grounded to the amplifier to minimize noise and receive the finest quality from the sound system. A “ground loop” signal in a turntable is when the player starts to make a buzzing noise. Therefore, grounding is the only way to fix the “ground loop” issue.
Detecting the Source of Unpleasant Sounds in a Turntable
Ground loops can happen either while using a direct drive turntable or a belt turntable. Meanwhile, you need to identify the source of the hum in your turntable before you can stop it.
You may hear two kinds of hums when your turntable is playing music. You can differentiate these hums by frequencies into the 60-hertz and 120-hertz hums. The 120-hertz hum exists as a result of the ground loop. Meanwhile, these hums differ in their pitches, as the 120-hertz hum is louder and more disturbing. In comparison, the 60-hertz hum has a lower pitch and is less audible.
Check whether the hum decreases as you reduce the volume and increases as you intensify the volume. If the hum follows your volume regulation, the turntable needs grounding. On the other hand, if the hum does not change with volume regulation but occurs when you switch between inputs, then the difficulty is probably arising from the source, and you may not ground the turntable.
Why You Should Ground Your Turntable
A turntable can produce an unsettling hum, mainly when the turntable receives data from an extremely sensitive cassette. Conversely, grounding a turntable enables one to listen to sounds from the record player without hearing any hum.
The risk of electrocution is one of the concerns of a defective turntable. Electrocution would most likely occur when a turntable’s case is metallic and live wires are touching the metallic turntable. It is likelier to occur with heftier devices.
When to Ground a Turntable
Turntables need grounding when they’re without a built-in preamp. In grounding a turntable, most turntables need a cable connected to the preamp, an amplifier, or a mixer. The turntable will make a humming sound if it is not grounded.
How to Ground a Record Player or Turntable without Ground Wire
You can create a replacement wire if your turntable lacks a ground wire. Use an insulated wire to ground the device.
To ground a turntable without ground wire, you need first to gather the materials you’ll need. Necessary materials include;
- Pinpoint nose pliers.
- Copper spade connectors.
- The grounding terminal of an amplifier.
- A gaffer tape for an amplifier without grounding terminal.
- A grounding wire fixed to the turntable.
- When the turntable does not have grounding wire, you’ll need fine insulated wire, approximately 5 feet made of 18 to 20-gauge stranded wire.
To ground the turntable, follow these steps.
1. Switch off All the Devices
Switch off the amplifier and turntable to reduce the risk of loud noises that may emerge from the devices during connection. The noise from the devices can be loud enough to cause shock, which will reduce when the devices are off.
2. Make a Ground Wire
Since you don’t have a ground wire, you’ll have to improvise by making one. Make your ground wire using your five feet-stranded wire of 18 to 20 gauge. Utilizing the pinpoint nose pliers, remove 0.6 to 0.8cm of the insulation from both wires ends. Next, connect your copper spade connectors to the end of the wires. If you couldn’t purchase the connectors, stripping the wire ends by about one inch would work.
3. Locate the Grounding Terminal
The grounding terminal should be on the amplifier’s rear and labeled as “Ground.” The grounding terminal should be either the typical screw terminal or a ridged shaft metallic post. After you’ve found the ground terminal point, unscrew it.
If you cannot find the grounding terminal, don’t get disturbed. You can use the grounding cable you made to ground the turntable.
4. Ensure the Measurements Are Accurate
The grounding wire is required for connection and must be long enough to reach the grounding terminal. Shorten the distance between the equipment if the grounding wire is not long enough.
5. Connect the Grounding Parts
Connect the grounding wire to the grounding terminal using the copper spade connection. Make the connection firm. Next, join the other tail of the ground wire to the amplifier’s ground terminal. If the amplifier lacks a grounding terminal, use gaffer tape to attach the grounding wire (from its copper spade) to the amplifier’s metal box.
If the copper spade is not attached to the wires, simply wind the wire around the turntable or amplifier’s ground connector. Now, secure the wire in place using electrical tape.
Attach the first open end of the grounding wire to a screw on the metal box of the amplifier. Ensure that the screw is not the terminal of the speaker. Afterward, attach the other open end of the grounding wire to a screw on the turntable. The screw should be on the chassis of the turntable.
6. Power the Devices
After grounding the turntable, test if the connection is done rightly. You will detect this when the music you listen to is devoid of humming.
For Turntables with Short Ground Wires
If the ground wire is short, elongate it by attaching any electrically conducting wire. A protective outer wrapping should surround the wire. It would be best to strip off the extension wire at both ends before joining one bare end to the ground cable at the small spade. The other bare wire end should be connected to the receiver’s grounding pin.
The unpleasant noise from ground loops could make using a turntable quite annoying. However, if you follow the steps listed and explained above, you should be back to enjoying quality sounds in no time.