Features
Inputs, Outputs, and Controls
Wiring Recommendation

Features

PWM MOSFET Power Supply: The Infinity Reference 7541a is equipped with a high-output PWM MOSFET power supply, which ensures optimum power delivery into numerous impedances with low distortion.

CEA-2006 Compliance: The specifications given by Infinity for the Reference Series 7541a amplifier comply with the new CEA-2006 Amplifier Power Standard from the CEA (Consumer Electronics Association). All manufacturers who comply with the standard can display the CEA-2006 logo on their product.

Protection Circuitry: The amp features 4-way protection, and will shut itself down in the following cases:

• DC Output: DC voltage is detected on the amplifier output
• Temperature: Amplifier is overheated
• Over/Under Voltage: Voltage at the +12V (Battery) terminal is less than 8.5V or more than 16V
• Short Circuit: Short circuit in speaker or speaker wire

Status LEDs: Three LEDs on top of the amplifier provide the status of the amplifier. The "Clip" LED indicates the amplifier is being overdriven, and the speakers may be in danger. The "Power" LED indicates the amplifier is on. The "Protection" LED flashes or glows to indicate the amplifier has entered the protection mode because of a malfunction.

Channel Configuration: The 7541a can be configured as a 4-channel amp for driving two pairs of full-range speakers, a 3-channel amp (bridging one set of channels) for driving one pair of full-range speakers and one subwoofer, or as a 2-channels (bridging both sets of channels) for driving two subwoofers.

Bass Boost: The amp is equipped with a variable 0-12dB bass boost at 50Hz. The bass boost affects only the rear channels.

Selectable High/Low Pass Filter: The 7541a has variable 12dB per octave, 32-320Hz crossovers for the front and rear channels. You can independently select high-pass or low-pass operation, or flat (for full-range operation) for each crossover.

Mono/Stereo Switch: A 2-way switch allows you to select stereo operation for full-range speakers or mono operation for subwoofers. There are switches for the front and rear channels for independent selection.

Inputs, Outputs, and Controls

Left Side of Amp:

• Preamp Output: 1 pair of gold-plated RCA jacks (amp provides a non-filtered, summed stereo signal for daisy-chaining additional amplifiers)
• Front Channels:
  • Preamp Input (Front): 1 pair of gold-plated RCA jacks for the front channels
  • High-Level Input (Front): 4-pin Molex jack for connecting the supplied 2-channel speaker level input harness to the head unit's front speaker outputs
  • Input Level: Rotary control to match the level of the front channels' input signal
  • Mono/Stereo Switch: 2-way switch to select mono or stereo operation for the front channels
  • Mode: 3-way switch to select the front channels' crossover mode: Flat (no filter), LP (low-pass), or HP (high-pass)
  • Freq: Rotary control to set the cutoff frequency of the front channels built-in crossover
• Rear Channels:
  • Bass Boost: Rotary control to set the level of the 50Hz bass boost (rear channels only)
  • Mono/Stereo Switch: 2-way switch to select mono or stereo operation for the rear channels
  • Mode: 3-way switch to select the rear channels' crossover mode: Flat (no filter), LP (low-pass), or HP (high-pass)
  • Freq: Rotary control to set the cutoff frequency of the rear channels built-in crossover
  • High-Level Input (Rear): 4-pin Molex jack for connecting the supplied 2-channel speaker level input harness to the head unit's rear speaker outputs
  • Input Level: Rotary control to match the level of the rear channels' input signal
  • Preamp Input (Rear): 1 pair of gold-plated RCA jacks for the rear channels

Right Side of Amp:

• Speaker Output: 8 Set screw terminals for connecting speaker wires; handles up to 8 gauge (16 gauge minimum recommended)
• Fuse: Slot for two 30A fuses (installed)
• Power:
  • +12V: Set screw terminal for power wire from battery; handles up to 4 gauge wire (8 gauge minimum recommended)
  • Remote: Set screw terminal for remote turn-on lead; handles up to 8 gauge wire (18 gauge minimum recommended)
  • Ground: Set screw terminal for ground; handles up to 4 gauge wire (8 gauge minimum recommended)

Wiring Recommendation

Fuse Rating: The 7541a has two 30-amp fuses for a total fuse rating of 60 amps. If you use an 8-gauge amp wiring kit, you should choose a kit which includes a 60-amp fuse to accommodate the amp's fuse rating. If the kit includes a 40-amp fuse, you should upgrade the fuse to a 60-amp fuse (211AGU60 or 142P60F4i). All of the 4-gauge amp wiring kits carried by Crutchfield include a 60-amp or 80-amp fuse.