Where this fits in the build
This is a system-control or DSP component. The correct choice depends on the signal path, channel count, routing, retained features and the rest of the amplifier and speaker plan.
Description
PAC AP4-GM61 AmpPRO 4 GM Bose MOST50 Amplifier Integration
On the supported GM Bose MOST50 systems, the factory audio is already digital before it reaches the amplifier. GM61 lets us get into that signal path before the Bose amp splits and processes it for the factory speakers.
AP4-GM61 extracts the audio from the MOST50 network and gives the aftermarket system front, rear, subwoofer and center-channel outputs while keeping the factory radio and supported vehicle audio functions in place. That is a much better place to start a real DSP or amplifier build than trying to sum a collection of already-processed Bose speaker channels back together.
Factory volume, fade, balance, bass, mid and treble remain integrated in supported applications, along with OnStar, Bluetooth audio, navigation, safety-system audio and warning chimes. The customer keeps the factory interface; the aftermarket system gets a cleaner signal to work with.
GM61 Keeps the Factory Bose Amplifier Connected
This is one of the important differences inside the GM AmpPRO family. GM61 uses the supported factory Bose amplifier for system communication, so that amplifier remains connected even when the new amplifiers take over the speaker channels we are upgrading.
If those speaker channels are being moved to aftermarket amplification, APH-GM02 can provide the clean return path into the vehicle’s original speaker wiring. That lets the factory module remain on the network without forcing us to keep using its power for the upgraded channels.
Digital Extraction With Optical Already Included
GM61 provides full-range analog outputs up to 5V RMS, including the center channel, but PAC also equips this digital-bus interface with the APA-TOS1 optical output. If the DSP accepts TOSLINK, that digital path is already part of the GM61 package rather than an optional accessory we have to add later.
That makes the interface useful for anything from a conventional multi-amplifier upgrade to a fully active DSP system where the factory radio and OnStar integration still need to behave normally.
Manufacturer Specifications
- Model: AP4-GM61
- Product type: PAC AmpPRO 4 MOST50 amplifier integration interface
- Application: Select 2014–2019 General Motors vehicles with compatible Bose MOST50 factory-amplified audio
- Signal extraction: Vehicle digital data bus / MOST50 architecture
- Analog outputs: Front, rear, subwoofer and center-channel preamp outputs
- Maximum analog output: 5V RMS
- Digital output: APA-TOS1 TOSLINK optical output included
- Factory amplifier: Remains connected in supported GM61 installations for system communication
- Factory controls retained: Volume, fade, balance, bass, mid and treble in supported applications
- Supported retained audio: OnStar, Bluetooth audio, navigation, safety-system audio and warning chimes
- Sub-level control: Included remote controller
- Speaker wiring option: APH-GM02 available separately where applicable
Included
- AP4-GM61 AmpPRO module
- Vehicle-specific plug-and-play harness
- APA-TOS1 optical-output hardware
- Bass / sub-level knob and harness
- Manufacturer documentation
Manufacturer: PAC