Whether or not you need two ground wires if you use a preamp depends on a few factors, including your setup and whether or not you are experiencing ground hum.
Ground hum is a low-frequency buzzing or humming sound that is caused by a difference in electrical potential between two components. It is most commonly experienced with turntables, as they are more susceptible to ground loops.
A ground loop is a circuit that is created when two components are connected to different ground points. This can happen when your turntable and preamp are plugged into different outlets, or when your turntable is connected to a metal chassis component that is not properly grounded.
The ground wire on your turntable is used to connect it to the same ground point as your preamplifier and amplifier. This helps to prevent ground loops and reduce ground hum.
If you are using a turntable with a built-in phono preamp, you will typically only need one ground wire. This is because the built-in preamp will usually share the same ground as the turntable chassis.
However, if you are using a separate phono preamp, you may need two ground wires. One ground wire will connect the turntable to the preamp, and the other will connect the preamp to the amplifier.
If you are experiencing ground hum, you can try connecting a second ground wire. If this does not solve the problem, you may need to try a different type of ground wire, such as a ground loop isolator.
Here are some additional tips for reducing ground hum:
- Make sure that all of your components are properly grounded. This means connecting them to the same ground point, such as a grounded outlet or a ground bus.
- Try using different RCA cables. Some RCA cables are more susceptible to ground hum than others.
- Avoid running RCA cables near power cords.
- Use a power conditioner or surge protector to help reduce noise from the power supply.
If you are still having problems with ground hum, you may need to consult with a professional audio technician.
When to use two ground wires
There are a few situations where you may want to use two ground wires, even if you are not experiencing ground hum:
- If you are using a turntable with a separate phono preamp, and the preamp is not properly grounded.
- If you have a complex audio system with multiple components, and you are having trouble getting rid of ground hum.
- If you are using a turntable in a professional setting, such as a recording studio.
Using two ground wires safely
If you do decide to use two ground wires, it is important to do so safely. Here are a few tips:
- Make sure that both ground wires are connected to the same ground point. This will help to prevent ground loops.
- Avoid connecting ground wires to different outlets. This can create a ground loop.
- If you are using a ground loop isolator, make sure that it is properly connected.
Whether or not you need two ground wires if you use a preamp depends on your setup and whether or not you are experiencing ground hum. If you are not sure, it is always best to consult with a professional audio technician.
