Line Level Ground Loop Isolator: A Solution to Unwanted Hum and Noise

When working with audio equipment, one of the most frustrating issues that can arise is unwanted hum and noise. This is particularly true when dealing with multiple devices connected together, as it's easy for ground loops to form. Ground loops occur when there are different electrical grounds between devices, causing a loop of current to flow back into the circuit. This can result in humming, buzzing, or even complete loss of signal.

In my own experience, I've encountered this issue firsthand with my Otari MTR-12 and other equipment. Despite using balanced signals and XLR cables, I still experienced a significant ground loop hum. To combat this problem, I turned to line level ground loop isolators.

These devices use transformers to isolate the signal and prevent ground loops from forming. They maintain a stable voltage point, allowing me to choose the desired level of isolation. With multiple types of equipment in play, including consumer and professional-level pieces, mixing boards, signal routers, computers, and more, I found it easiest to plug any device with low-level inputs and outputs into a line conditioner and isolation unit(s).

In addition to ground loop isolators, band-pass filters can also be useful in eliminating unwanted frequencies. These filters pass frequencies within a certain range while rejecting those outside that range. For example, if you have crossover issues in your radio equipment, a band-pass filter can help resolve the problem.

Other types of filters, such as low-pass and high-pass filters, can also be used to eliminate specific frequency ranges. Low-pass filters pass signals with frequencies lower than a certain cutoff point while attenuating higher frequencies, while high-pass filters do the opposite.

When choosing a line level ground loop isolator, it's important to consider the transformer ratio and harmonic suppressor capabilities. A 1:1 ratio transformer, for example, will prevent any 60-cycle hum voltage from passing through to the secondary coil winding. Additionally, a transmitter with a harmonic suppressor can help eliminate transmitting at frequencies that are multiples of the original carrier frequency.

In conclusion, line level ground loop isolators are an effective solution to unwanted hum and noise caused by ground loops. By using these devices in conjunction with other tools like band-pass filters, low-pass filters, and high-pass filters, you can ensure a clean and stable audio signal. Whether you're working with radio equipment or any other type of audio gear, line level ground loop isolators are an essential tool to have in your arsenal.

Line level ground loop isolator