The HELIX AAC.3 HP is a high-low converter that generates high-quality RCA preamplifier outputs from speaker-level signals to allow the addition of aftermarket power amplifiers to factory sound systems, including radios with factory-installed amplifiers that use speaker diagnosis.

It features the ADEP.3P diagnostic bypass circuit, a Double Activation Circuit for remote turn-on via DC offset or signal detection, and a Power Save Mode that disables the remote after two minutes without audio. The AAC.3 HP offers a wide frequency response to support high-resolution audio and uses sealed gold plated RCA connectors for lossless signal transmission. For OEM systems without a factory amplifier, the AAC.3 model is recommended.