Alpine PDR-M65 - User Manual

The Alpine PDR-M65 Mono Power Amplifier and PDR-F50 4 Channel Power Amplifier are designed for mobile 12V applications, providing high-quality audio output for car audio systems. These amplifiers are engineered to deliver robust sound performance while incorporating features for safe and effective operation.

Function Description

The PDR-M65 is a mono power amplifier, ideal for driving subwoofers, while the PDR-F50 is a 4-channel power amplifier suitable for full-range speakers, tweeters, or mid-range systems, and can also be bridged for subwoofer applications. Both units are designed to amplify audio signals from a head unit, delivering increased power to speakers.

Key controls and features include:

Speaker Output Terminals: These terminals are designed for connecting speakers. For the PDR-M65, the output is monaural, and reversing subwoofer polarity may be beneficial for optimal bass. For the PDR-F50, bridged connections are possible, where the left positive connects to the speaker's positive terminal and the right negative to the speaker's negative terminal. It is crucial to observe correct polarity and avoid connecting speaker (-) terminals to the vehicle's chassis.
RCA Input Jacks: These jacks allow connection to the line-out leads of a head unit using RCA extension cables. Proper channel connections (Left to Left, Right to Right) must be observed.
Pre-Out Jacks (PDR-M65 only): The PDR-M65 includes line-level pre-out jacks, providing a full-range output unaffected by the crossover, making it suitable for driving a second subwoofer amplifier.
Power Supply Terminal: This terminal is for connecting the battery lead, ground lead, and remote turn-on lead.
Remote Bass Control (PDR-M65 only): An optional Remote Bass Control Unit can be connected to adjust the output level remotely, complementing the gain level setting between the amplifier and head unit.
Subsonic Filter (PDR-M65 only): This filter cuts ultra-low frequencies from the input signal before amplification. It is useful for protecting smaller speakers, minimizing wasted power from inaudible sound, and preventing over-excursion of subwoofers in vented enclosures below their tuning frequency.
Crossover Frequency Adjustment Knob (PDR-M65: LP FILTER): This knob allows adjustment of the crossover frequency between 50 to 400 Hz for the PDR-M65.
Bass EQ Adjustment Knob (PDR-M65 only): This knob provides a 50 Hz bass boost up to +12 dB to fine-tune bass response.
Input Gain Adjustment Control: This control sets the amplifier's input gain. It should be adjusted by first increasing the head unit volume until distortion, then reducing it slightly, and finally increasing the amplifier gain until distortion, then reducing it slightly to achieve the optimum setting.
Crossover Mode Selector Switch (PDR-F50 only): This switch offers three modes:
- OFF: For full-range speakers or when using an external electronic crossover, providing full frequency bandwidth.
- HP (High Pass): For tweeter/midrange systems, attenuating frequencies below the crossover point at 12 dB/octave.
- LP (Low Pass): For subwoofers, attenuating frequencies above the crossover point at 12 dB/octave.
Bass EQ Selector Switch (CH-3/4) (PDR-F50 only): This switch sets a 50 Hz bass boost to "+6 dB" or "+12 dB" for subwoofer applications.
Input Channel Selector Switch (PDR-F50 only): This switch selects between 2-channel or 4-channel input modes. In "1/2" mode, the signal from CH-1/2 is copied to CH-3/4, eliminating the need for Y-adapters. In "3/4" mode, both CH-1/2 and CH-3/4 inputs are independent, requiring a 4-channel source.
Power Indicator: A blue light indicates normal amplifier circuit operation. A blinking red light signifies high operating temperature, while a solid red light indicates an abnormal amplifier circuit, electrical short, or high supply current.

Usage Features

Installation: The amplifiers generate considerable heat, so they should be mounted in a location with free air circulation, such as inside the trunk. Installation involves removing the top cover, marking screw locations using the amplifier as a template, drilling holes, and securing the unit with self-tapping screws.
Wiring: Proper wiring is critical for safety and performance.
- Battery Lead: An in-line fuse with the correct ampere rating (70 amp for PDR-M65, 60 amp for PDR-F50) must be added as close as possible to the battery's positive (+) terminal. The minimum required wire gauge is 4 AWG/21 mm².
- Ground Lead: Connect securely to a clean, bare metal spot on the vehicle's chassis. All audio components should be grounded to the same point to prevent ground loops. The minimum required wire gauge is 4 AWG/21 mm².
- Remote Turn-On Lead: Connect to the remote turn-on (positive trigger, (+) 12V only) lead of the head unit. If a remote turn-on lead is unavailable, or if the head unit's power antenna lead has limitations, the amplifier's turn-on lead must be connected to a switched power source (ignition) with a 3A fuse. An optional SPST switch can be installed for manual control.
- Speaker Output Leads: The recommended wire gauge is 8 AWG (8 mm²) for PDR-M65 and 12 AWG (3 mm²) for PDR-F50.
- Wire Lead Connections: Insulation should be removed from wire ends by 7-10 mm. Set screws should be tightened with the provided hexagon wrench. Insulated shrink tubing should be used to cover any exposed wire.
Noise Prevention: To prevent external noise, route leads at least 10 cm (4") away from the vehicle's harness and keep battery power leads separate from other leads.
Bridged Connections (PDR-F50): When bridging, ensure proper connections to avoid low output. A Y-adapter is not required if a stereo/mono pair line output is used to drive both inputs of the bridged amp.

Maintenance Features

Fuse Replacement: Use the correct ampere rating (35A x 2 for PDR-M65, 30A x 2 for PDR-F50) when replacing fuses to prevent fire or electric shock.
Troubleshooting Power Indicator:
- Blinking Red (High Operating Temperature): Decrease the vehicle's interior temperature. The indicator should change to blue.
- Solid Red (Abnormal Circuit/Short/High Current): Turn off the power supply, eliminate the cause, then restart. If it remains red, consult a dealer.
- Solid Red (High Power Supply Voltage): Use the correct power supply voltage. The indicator should change to blue.
Switch Settings: Before adjusting any selector switch, turn off the power and use a small screwdriver to change the setting.
General Care: Avoid installing the unit in locations with high moisture or dust, as this can lead to product failure. Do not block vents or radiator panels to prevent heat buildup. Do not disassemble or alter the unit, as this may cause accidents, fire, or electric shock. If a problem occurs, halt use immediately and return the unit to an authorized Alpine dealer for repair.
Warranty Service: For warranty service, provide a detailed problem description, proof of purchase, and securely package the product for shipment to an authorized Alpine Service Center or Alpine.

Alpine PDR-M65 Specifications

General

Power Output (RMS)	65W x 4 (4Ω)
Power Output (Peak)	130 watts x 4
RMS Power Output	65 watts x 4
Bridged Power Output	130W x 2 (4Ω)
CEA-2006 Power Output	65W x 4 @ 4 Ohms
Frequency Response	10 Hz - 30 kHz
Input Sensitivity	0.2V - 4V