Audiofrog A150.4D

Features
Controls
Connections

Features

Overview: The Audiofrog A150.4D is a full-range Class D 4-channel amplifier, effectively two full range 2-channel amps built into one chassis. Each section of the amp is bridgeable, so it can be wired as 4-channel, 3-channel, or 2-channel. The built-in crossovers are flexible enough to bi-amp a pair of component speakers.

Differential Inputs: The amp uses differential signal inputs to reduce the possibility of creating a ground loop or picking up any radiated noise. It's best to use twisted pair RCA cable rather than shielded coaxial cable. Twisted pair cable is designed to expose both conductors equally to radiated noise so it can be cancelled in the preamp. Differential inputs are suitable for connection to both the single ended line level output of head units and signal processors (RCA) and for connection to the balanced, speaker level output of head units and factory installed amplifiers.

Protection Circuits: The amplifier is equipped with protection circuits and will mute if the power supply input voltage is too high or too low, the output is shorted, or the heat sink is too hot.

Controls

Removable Cover: A removable cover hides the amplifier's top mounted controls, ensuring the settings are not accidentally changed. (A small Phillips Head screw driver, not included, is needed to remove the control cover.)

Turn-on Mode: 3-position switch, the amp turns on when it senses:

• Signal: an audio signal on the speaker level inputs (800mV) or RCA line inputs (45mV)
• Offset: the 6 volt DC Offset on the speaker level inputs
• Remote: +12 volts on the remote turn-on terminal

Level (Gain): Channels 1/2 and 3/4 have independent rotary level controls. The input level (sensitivity) range is 0.5-10 volts on the line level inputs and 0.8-30 volts on the speaker level inputs.

Input Configuration: 3-position switch

• 3-Channel: use when connecting two input channels (1/2) and bridging channels 3/4 to power a subwoofer
• 2-Channel: use when connecting two input channels (1/2) and not bridging any channels
• 4-Channel: use when connecting all four input channels

Crossovers: Channels 1/2 and 3/4 have independent, identical crossovers with several options:

• Filter Type: 3-position switch
  • HP: high pass
  • None: full range; no crossover is engaged
  • BP: band pass; both high pass and low pass crossovers are engaged simultaneously; the high pass crossover point should be set at least one octave lower than the low pass crossover point
• High Pass Controls:
  • Range Multiplier: 2-position switch, X1 and X10, to set the crossover point range
  • Frequency: rotary dial to set crossover point; 20-400 Hz with range switch in the X1 position, 200-4,000 Hz with range switch in the X10 position
• Low Pass Controls:
  • Range Multiplier: 2-position switch, X1 and X10, to set the crossover point range
  • Frequency: rotary dial to set crossover point; 50-500 Hz with range switch in the X1 position, 500-5,000 Hz with range switch in the X10 position

Connections

Terminal Layout: For wiring convenience, all of the amplifier's inputs and outputs are on one side.

Power Input: Two set-screw terminals are provided for connecting the power and ground cables. The terminals can accept up to 4-gauge wire and are tightened/loosened with a 3mm Allen wrench (not included).

Remote Turn-on: The remote turn-on set screw terminal will accept up to 10-gauge wire and is tightened/loosened with a 2mm Allen wrench (not included).

Speaker Outputs: The four pair of screw clamp speaker output terminals accept up to 12-gauge wire and are tightened/loosened with a Phillips Head screw driver (not included).

Signal Input: use one or the other, not both:

• Line Level Inputs: two pair of RCA jacks, labeled channels 1/2 and 3/4
• Speaker Level Inputs: if needed, use the included 8-pin speaker input harness

Fuses: The amp has no fuse mounted to the chassis; a 60-amp fuse must be wired in-line no more than 18 inches from the battery.