Audioproject A259 - NF Interference Filter Car Radio Suppressor Noise Filter RCA Plug Gold-Plated (20 Hz - 33 kHz) Ground Loop Isolator Car HiFi Car Amplifier Subwoofer by Amazon.co.uk

• With mounting an accessory car radio or amplifier, unwanted noise often occurs, which are caused by e.g. humming, (humming loop) make noise or whistles noticeable. This is caused by different mass potentials from the car radio and power amplifiers or by incorrect installation of the signal cable to the amplifier throughout the car hi-fi system.

• This NF suppression filter (or decoupler, noise filter, ground loop insulator) can completely eliminate or significantly reduce most of these noise in the car. The Audioproject A259 has a large and high-quality transformer (separating transformer, power supply), unlike very cheap devices where only a small transformer is often installed. This is cheaper to produce, but this is noticeable in a worse suppression quality.

• If, despite the installation of this filter, the interference in the audio system cannot be eliminated or improved, then the wiring of the car system must be checked because then a very good filter can no longer help. Frequency range: 20 - 33000 Hz, transmission ratio: 1:1, impedance: 10 ohms, distortion: less than 0.001%

• Tip! Power cable and signal cable (RCA cable) do not lay side by side in the car as there is an invisible magnetic field around the power cable, which has a disturbing effect on the signal transmission of the RCA cable (e.g. noise). This then acts like an antenna. Do not wind up too long cables at the end (power and signal), but store separately.

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