AP4-CH41

Introduction and Features

The AP4-CH41 provides a 6-channel pre-amp output for use with aftermarket audio equipment. Using the full range, fixed level head unit output, in conjunction with CAN messages, the AP4-CH41 delivers a variable 5v RMS pre-amp output with fading, balance, equalization, and level control capabilities. The module also retains all audio from other vehicle features such as factory navigation prompts, Bluetooth, uConnect, and parking sensor chimes. A data controlled remote amplifier turn on wire is also provided by the AP4-CH41. When used in conjunction with the APA-TOS1 (sold separately), the module can provide a variable 2-channel fiber optic digital audio output (TOSLINK).

Important Notes

1. This interface is only compatible in vehicles equipped with a data-bus controlled premium sound system. To verify compatibility, look for an Alpine, Beats, or Harmon Kardon badge on the door speakers, center speaker, or factory sub woofer. If none of these brands are shown, check for the presence of a center speaker or sub woofer.
2. The factory amplifier must remain connected, and in the vehicle after the AmpPRO has been installed.
3. The remote output is rated at 2A of current. If more current is needed an external relay must be used.
4. Channels 5 and 6 are non-fading outputs. The output level of channels 5 and 6 can be controlled using the supplied level control knob.
5. The chime volume and minimum volume levels are set to 0 dB by default. If you are happy with this level in your particular application then additional adjustment is not required. Please refer to the Setup and Configuration section on page 2 for more details.
6. The level control knob must be connected in order to manually adjust the chime volume and minimum volume settings.
7. The factory radio's speed controlled volume and surround sound mode are not supported by the AP4 outputs.
8. When using the TOSLINK output (APA-TOS1 sold separately), all chimes must be routed through the front output using DIP switch 1.
9. No adjustments can be made manually using the programming button, or the factory SWC when the module is connected to a PC.

Wiring Connection Chart

The wiring diagram illustrates the connections for the AP4-CH41. It shows the main unit connected to the 'To Radio' via the 'AP4-CH41-HAR' harness, and to the 'To Vehicle Harness'. Key connection points include 'Remote Turn On Output (2A Max Output)', 'Non-Fading Level Control Knob', and various output channels labeled 'Front 1(L) 2(R)', 'Rear 3(L) 4(R)', and 'Non-Fading 5(L) 6(R)' leading 'To Aftermarket Amplifier'.

Module Layout

The module layout shows the physical arrangement of the AP4-CH41. Prominent features include the 'Feature Select DIP switches' (numbered 1-4), a connection port for the 'Non-Fading Level Control Knob', an 'Interface Connector 1', an 'Expansion Port', a 'Programming Button', and a 'USB Connection' ?. The module also features a 'TOSLINK Output (APA-TOS1 sold separately)' and two status LEDs (LED 1 ?, LED 2 ?). Output connectors are clearly labeled: 'Front Output Ch. 1(L) and 2(R)', 'Rear Output Ch. 3(L) and 4(R)', and 'Non-Fading Output Ch. 5(L) and 6(R)'.

Installation

Set DIP switches ⚙️ to the ON position to activate the corresponding features. Set DIP switches ⚙️ to the OFF position for any features that are not desired.

Installation Steps:

1. Remove factory radio.
2. Disconnect the main 52-pin factory harness from radio.
3. Connect AmpPRO harness to vehicle harness ?.
4. Connect AmpPRO harness to factory radio.
5. Set any feature DIP switches ⚙️ that apply to your install.
   • DIP switch 1 is used for two channel mode. In this mode, both the TOSLINK and front RCA outputs (1 and 2) become non-fading outputs. All rear chimes ? will also be routed through these outputs in two channel mode.
   • Set DIP switch 2 ON (down) to lower the RCA output voltage to 4v. Leave DIP switch 2 OFF (up) to keep the RCA output voltage at 5v. See troubleshooting section on page 5 for more details.
   • DIP switches 3 and 4 are not used.
6. If you are using the APA-TOS1 (sold separately), refer to the instructions included with that product for its installation.
7. Connect the AmpPRO harness to the module.
8. Connect the level control knob ?️ to the module and install in an accessible location.
9. Connect the signal cables and remote input from the aftermarket amplifier ?.

Setup and Configuration

Follow these steps for initial setup:

1. Turn the ignition on. LED 1 ? on the interface will turn on and the +12v remote output will turn on.
2. Set the amp gain(s) to the desired level. It is recommended to use an oscilloscope and test tones. Refer to the MECP Advanced study guide (p. 360) if unfamiliar with this process.
3. Check volume ?, balance, fade, and EQ settings.
4. If you wish to adjust the chime ? volume or minimum volume, use one of the methods outlined below. If the default levels are satisfactory, no adjustments are necessary.

Manually Setting the Chime Volume

You can manually set the level of the factory chime ? using either the programming button ⚙️ on the side of the interface or the factory SWC. For PC app adjustments, proceed to the AmpPRO PC app section. Note: The level control knob ?️ must be connected to the module for these methods.

• Using the Programming Button ⚙️:
  1. Start with the level control knob ?️ turned all the way down [counter-clockwise].
  2. Press the programming button ⚙️ on the side of the interface.
  3. LED 1 ? will turn green and the chimes ? will begin continuously sounding.
  4. Turn the level control knob ?️ clockwise until the desired chime level is reached.
  5. Press the programming button ⚙️ twice or wait ten seconds to exit the settings.
• Using the Factory SWC:
  1. Start with the level control knob ?️ turned all the way down.
  2. Press and hold the track down button on the factory SWC (Back left of steering wheel) for approximately ten seconds. Note: The radio will respond to SWC commands during this process, which is normal and does not affect AP4 operation.
  3. LED 1 ? will turn green and the chimes ? will begin continuously sounding.
  4. Turn the level control knob ?️ clockwise until the desired chime level is reached.
  5. Press the programming button ⚙️ twice or wait ten seconds to exit the settings.

Manually Setting the Minimum Volume

If the minimum volume of the radio (factory radio volume level 1) is too loud, you can manually set the minimum volume level using either the programming button ⚙️ or the factory SWC. For PC app adjustments, proceed to the AmpPRO PC app section. Note: The level control knob ?️ must be connected to the module for these methods.

• Using the Programming Button ⚙️:
  1. Start with the level control knob ?️ turned all the way down [counter-clockwise].
  2. Set the amp gains ? to the desired level.
  3. Set the volume ? on the factory radio ? to 1.
  4. Press the programming button ⚙️ on the side of the interface twice.
  5. LED 1 ? will turn amber and the chimes ? will begin sounding every five seconds.
  6. Turn the level control knob ?️ clockwise until the desired minimum volume level is reached.
  7. Press the programming button ⚙️ once or wait ten seconds to exit the settings.
• Using the Factory SWC:
  1. Start with the level control knob ?️ turned all the way down [counter-clockwise].
  2. Set the amp gains ? to the desired level.
  3. Set the volume ? on the factory radio ? to 1.
  4. Press and hold the track up button on the factory SWC (Back left of steering wheel) for approximately ten seconds. Note: The radio will respond to SWC commands during this process, which is normal and does not affect AP4 operation.
  5. LED 1 ? will turn amber and the chimes ? will begin sounding every five seconds.
  6. Turn the level control knob ?️ clockwise until the desired minimum volume level is reached.
  7. Press the programming button ⚙️ once or wait ten seconds to exit the settings.

AmpPRO PC App

Use of the AmpPRO PC App ? allows you to:

• Configure User Interface Options such as:
  • Minimum Volume Level ?
  • Chime Volume Level ?
  • Enable / Disable AP4 Chimes ✔️ / ❌
  • Enable / Disable factory EQ ✔️ / ❌
  • Set Bass / Mid / Treble center frequencies ? and Q factor ?
• Update Product Firmware ?
• Read Firmware / Hardware Versions
• Download the AmpPRO app at: http://aampglobal.com/appdownloads

Note: These settings can be adjusted with the module installed in the vehicle, or on the bench. However, it is recommended to make adjustments with the module installed and the factory radio ? on, so that the changes can be heard.

Setting Explanations:

• Minimum Volume Level: Sets the minimum volume level of the factory radio (factory radio volume level 1).
• Chime Volume Level: Sets the volume of the AP4 chimes (e.g., park sensors).
• Front / Rear Chimes Enabled: Allows enabling/disabling AP4 chimes (e.g., park sensors). This is used when mixing factory and aftermarket speakers.
• 3 Band EQ Enabled: Allows enabling/disabling the 3-band factory EQ.
• Bass / Mid / Treble Freq / Q Factor: Sets the center frequency and Q Factor for the 3-band factory EQ. The Q Factor determines how many adjacent frequencies are affected. A lower Q Factor affects more frequencies.

Available Frequencies and Q Factors

Firmware Updates

The AmpPRO app ? also allows you to update the interface with new firmware ? as it becomes available. Please visit www.pac-audio.com or contact tech support for firmware updates.

Update Process:

1. Connect the interface to your PC ?.
2. Select "Firmware", then "Update Firmware".
3. Select "Select File".
4. Browse to the saved firmware file and select it.
5. This will begin the updating process. Once finished, disconnect the interface from the PC and resume normal operation.

Restoring Factory Settings

You can restore the interface to factory default settings by pressing and holding the programming button ⚙️ on the side of the module until the status LEDs ? start blinking red. Once the LEDs ? start blinking red, release the button. This reset restores the following settings to their factory defaults:

• Chime volume level ?
• Enable / Disable Factory Chimes ✔️ / ❌
• Minimum volume level ?
• Enable / Disable factory EQ ✔️ / ❌
• Factory EQ frequency ?
• Factory EQ Q factor ?

Troubleshooting

1. Hiss at high amp gain: Set feature DIP switch 2 ⚙️ to the ON (down) position to lower the output voltage of the AP4 to 4v. If hiss persists, lower your amp gains until it is gone.
2. Cannot hear uConnect or nav voice: Use the volume knob ?️ while either of these voice prompts are active to adjust voice volume.
3. Cannot hear chimes: Set chime volume using the process outlined in Setup and Configuration, or using the AmpPRO app ?. If chimes are still not heard, ensure you are using the remote output from the AP4 to turn on your aftermarket amplifier ?.
4. Low volume setting on radio is too loud: Set minimum volume using the process outlined in Setup and Configuration, or using the AmpPRO PC app ?.
5. Module unresponsive or not powering up: If the AmpPRO module becomes unresponsive, or will not power up with the key on, you can reset the interface by turning the key to the ignition position, then pressing and holding the Volume Down button on the factory SWC for 12 seconds until a tone is heard.

LED Legend