Are you tired of hearing a frustrating hum when listening to your turntable?
It’s a common problem that can be caused by a ground loop, which occurs when there is a lack of grounding between the turntable and amplifier.
But fear not, there is a solution: grounding your phono pre-amp.
In this article, we’ll explore the benefits of grounding your turntable and how to do it properly to eliminate that annoying hum and enjoy your music the way it was meant to be heard.
So sit back, relax, and let’s dive into the world of turntable grounding.
Should I Ground My Phono Pre-Amp To Eliminate Hum
The short answer is yes, grounding your phono pre-amp can help eliminate hum.
A phono pre-amp is an essential component for playing vinyl records on a modern stereo system. It amplifies the low-level signal from the turntable and applies the RIAA equalization curve to restore the original sound quality of the recording.
However, if the phono pre-amp is not grounded properly, it can create a ground loop that causes a humming noise in your speakers. This is especially common when using a separate phono pre-amp with an integrated amplifier or active speakers.
Grounding your phono pre-amp will help to eliminate this hum by providing a direct path for electrical current to flow between the turntable and amplifier. This will ensure that both components have the same ground potential and voltage, preventing any interference or noise from occurring.
Understanding Ground Loops And Hum
Ground loops are a common cause of hum in audio systems, including those involving record players and phono pre-amps. A ground loop occurs when there are multiple paths for electrical current to flow between two or more components in a system. This can create a difference in potential at grounding points, leading to interference and noise.
There are two basic types of hum that can occur in an audio system: 60Hz hum and 120Hz buzz. 60Hz hum is typically caused by poor shielding, cable problems, or proximity to strong magnetic fields. On the other hand, 120Hz buzz is often the result of ground loops.
To determine which type of hum you are experiencing, listen to the sound and try to identify the frequency. If it is a low-pitched hum at around 60Hz, it is likely caused by something other than a ground loop. If it is a higher-pitched buzz at around 120Hz, it is likely a ground loop issue.
There are several ways to fix a ground loop problem in your system. One method is to lift the Earth ground on either device at the line level. This can be done by modifying the cable to include an AC path between grounds or using a small capacitor. However, this method should be used with caution as it can cause frequency response variations depending on capacitor size and equipment source impedance.
A better solution for eliminating ground loops in unbalanced connections is to use an audio line isolation transformer. This device provides a clean signal path by breaking the ground loop and isolating the components from each other.
The Importance Of Grounding Your Phono Pre-Amp
Grounding your phono pre-amp is crucial to achieving optimal sound quality and preventing unwanted noise. A ground loop can occur when there is a difference in ground potential between the turntable and amplifier, causing a 60-cycle hum to pass through the audio cables. This can be especially noticeable with the phono input selected, as preamplifiers for phono inputs are deeply sensitive.
Proper grounding ensures that the electrical current flows smoothly between the turntable and amplifier, without any interference or noise. This is particularly important when using a separate phono pre-amp with an integrated amplifier or active speakers.
To ground your phono pre-amp correctly, you need to connect the ground wire from your turntable to the grounding screw on your phono pre-amp, and then connect another wire from the pre-amp’s grounding screw to the grounding screw on your amplifier. It is important not to connect the ground wire to the mains protective earth, as this can cause further issues.
How To Properly Ground Your Phono Pre-Amp
To properly ground your phono pre-amp, you will need to follow a few simple steps.
1. Locate the grounding terminal on your phono pre-amp. This is typically a screw terminal located on the back of the device, labeled “ground.”
2. Cut a length of thin speaker wire and strip the ends.
3. Connect one end of the wire to the grounding terminal on your phono pre-amp.
4. Touch the other end of the wire to the grounding terminal on your turntable. This is typically a screw terminal or metal post with contorted knots located on the back of the turntable, labeled “ground.”
5. If your turntable is connected to an amplifier or receiver, you may also need to ground the amplifier or receiver. To do this, locate the grounding terminal on the amplifier or receiver and connect it to the grounding terminal on your phono pre-amp using another length of speaker wire.
It’s important to note that not all phono pre-amps require grounding. If your phono pre-amp has a built-in ground wire or if you have never experienced any hum or interference, then you may not need to ground your phono pre-amp. However, if you do experience humming or interference, grounding your phono pre-amp is a simple and effective solution.
Troubleshooting Grounding Issues
If you are experiencing humming noise despite grounding your phono pre-amp, there are a few troubleshooting steps you can take to identify and fix the issue.
First, make sure that your turntable has a ground wire and that it is properly connected to the GND screw on the back of your receiver or amplifier. If your turntable does not have a ground wire, you can try connecting a piece of speaker wire from a metal screw on the turntable to another metal screw on the receiver to establish a good metal-to-metal connection.
If you have confirmed that your turntable is properly grounded, but are still hearing humming noise, try disconnecting all other components from your system and see if the noise persists. If it goes away, then you likely have a ground loop caused by another component in your system. In this case, try connecting each component one by one until you identify the culprit and then ground that component separately.
If none of these steps solve the issue, you may want to consider investing in an isolation transformer or a ground loop isolator. These devices can help break the electrical connection between components and eliminate any interference or noise caused by ground loops.
Other Tips For Reducing Turntable Hum
In addition to grounding your phono pre-amp, there are other tips you can follow to further reduce turntable hum. Here are some suggestions:
1. Use a ground wire: Make sure to ground your turntable properly using a ground wire. This will help to eliminate any electrical interference that may be causing the humming noise.
2. Move other wires away from each other: Move other wires from audio components away from each other. This includes power cords, speaker wires, and any other cables. This will help to reduce any interference that may be caused by these wires.
3. Move your speakers to a different surface: Sometimes, the surface that your speakers are placed on can cause vibrations that result in humming noise. Try moving your speakers to a different surface, such as a bookshelf or dedicated speaker stand, to see if this helps.
4. Purchase a standalone preamp: If you’re using an integrated amplifier or active speakers with a built-in phono pre-amp, consider purchasing a standalone preamp instead. This will allow you to have more control over the grounding and wiring of your system, which can help to reduce hum.
By following these tips, you can further reduce turntable hum and enjoy high-quality sound from your vinyl records.
