So you're upgrading the sound in your car. Why might you want to use a "network preamp" to bring audio signals out of your stock sound system? Because upgrading the sound system in a car is more complex than it used to be. 

Zen Audio has received dozens of inquiries asking how to install network preamps or amplifiers in Fords without a B&O sound package. Before 2025, this was impractical - expensive OEM hardware had to be installed. As of the 2025 model year, this is no longer required - 2025 and newer Ford ACM head units contain the necessary circuity - but it must be activated! 

For many years, automotive sound systems risked system noise and distortion due to a tortuous signal path for low-voltage analog preamp signals.

In Fords, ACM stands for Audio Control Module - that means “head unit” to those of us in aftermarket audio. In base audio sound packages, the ACM “deck power” amplifies the front and rear speakers with around 25 watts each.(In pre-2025 models, the ACM used a BTL Class B IC; in 2025+, the IC is usually a Class D amplifier with 25W RMS). 

In an audio system, “pre-amp” functions are performed on signals which have not yet been amplified. The preamplifier is in between the source or sources and the amplifier in the signal chain. It might be a standalone component, or it might be a section within another component (the “preamp section”).

OEM systems are limited in the design stage - they can't have a big heat sink, they can't have a big power wire, and so they can't use much current or dissipate much waste heat. This means they never, ever,. have enough power