Alpine R-A90S R Series 6-channel car amplifier — 75 watts RMS x 4 at 4 ohms + 250 watts RMS x 2 at 2 ohms

Features

Overview: The Alpine R-A90S 6-channel amplifier is effectively two full range amps built into one chassis, a 4-channel 4 x 75 watt (labeled Channel 1/2 and Channel 3/4), and a 2-channel 2 x 150 watt (labeled Channel 5/6). Each section of the amp is bridgeable, so it can be wired as 6-channel, 5-channel, 4-channel, or 3-channel.

CTA-2006 Compliant: CTA-2006 is a system of testing and measurement for mobile audio amplifiers. This voluntary standard advocates a uniform method for measuring an amplifier's RMS power output and signal-to-noise ratio. The criteria for measuring amplifier power uses a DC input voltage of 14.4 volts and the RMS power output is measured over a frequency range of 20 Hz to 20 kHz (for full range amplifiers), with 1% or less Total Harmonic Distortion plus noise (THD+N). Signal-to-Noise ratio is measured in weighted absolute decibels (dBA) at a reference of 1 watt into 4 ohms. CTA-2006 standards allow consumers to compare car amplifiers and receivers under the same conditions (apples to apples).

CTA-2006 Specifications:

• Power Output: 75 watts RMS x 4 (channels 1-4) and 150 watts RMS x 2 (channels 5-6) into 4Ω
• Signal to Noise Ratio: 85 dBA (measured at 1 watt into 4Ω)

Other Specifications:

• Power Output:
  • 2Ω: 100 watts RMS x 4 (channels 1-4) and 250 watts RMS x 2 (channels 5-6); 14.4 volts, ≤1.0% THD+N)
  • Bridged: 200 watts RMS x 2 (channels 1-4) and 500 watts RMS x 1 (channels 5-6); 14.4 volts into 4Ω
• Signal to Noise Ratio: 103 dB (channels 1-4) and 106 dB (channels 5-6); at rated power output, 4Ω

Hi-Res Frequency Response: The Alpine R-A90S offers a wide frequency range for compatibility with Hi-Resolution Audio.

• +0/-3 dB (1W into 4Ω): 10 Hz - 45 kHz
• +0/-1 dB (1W into 4Ω): 20 Hz - 20 kHz

Controls

Gain Control: There are independent rotary gain controls for channels 1/2, channels 3/4, and channels 5/6. The amp will accept line level signals from 0.2 volts to 4.0 volts or speaker level signals from 0.5 volts to 10 volts.

Input Level: Set the input level switch to match the type of input signal used (Hi for speaker level and Lo for line level).

Input Channel: There are two Input Channel switches to select which input feeds channels 3/4 and 5/6. Channels 1/2 are always fed by inputs 1/2.

• Channel 3/4: 2-position switch; choose which inputs feed channels 3/4; 1/2 or 3/4
• Channel 5/6: 2-position switch; choose which inputs feed channels 5/6; 1/2 or 5/6

Crossovers: Channels 1/2, 3/4, and 5/6 have independent crossovers. Each crossover has a switch to direct how it operates and all crossovers have a slope of 12dB/octave.

• Channel 1/2:
  • Off: output is full range
  • HP: High Pass; crossover point is adjustable from 50 Hz to 400 Hz
  • HP-H: used when powering a pair of tweeters; crossover point is adjustable from 400 Hz to 6 kHz
• Channel 3/4:
  • Off: output is full range
  • HP: High Pass; crossover point is adjustable from 50 Hz to 400 Hz
  • BP: Band Pass; two crossover points are set, high pass is adjustable from 50 Hz to 400 Hz and the low pass is adjustable from 400 Hz to 6 kHz
• Channel 5/6:
  • Off: output is full range
  • LP: Low Pass; crossover point is adjustable from 50 Hz to 400 Hz

Optional Remote Control: The amplifier has an RJ-25 jack for adding the optional RUX-KNOB.2 wired remote level control for adjusting the channel 5/6 output remotely. The remote has a 18 dB adjustment range (-18 dB to 0 dB relative to the gain setting).

Connections

Power/Ground: Two set-screw terminals connect the power and ground cables. The terminals accept up to 4-gauge wire (a 4-gauge wiring kit is recommended). The set screws are tightened/loosened with the included 3mm Allen wrench.

Remote Turn-on: The remote turn-on set screw terminal will accept up to 10-gauge wire. The set screw is tightened/loosened with the included 2mm Allen wrench.

Speaker Outputs: The six pair of speaker outputs' set-screw terminals will accept up to 10-gauge wire. The set screws are tightened/loosened with the included 2mm Allen wrench.

Signal Input: Three pair of RCA jacks, labeled Channel 1/2, Channel 3/4, and Channel 5/6 connect to line level or speaker level input signals. If connecting the source unit's speaker wire to the input jacks, use a Speaker-to-RCA adapter or splice speaker wire to an RCA plug. When using a speaker level input signal, it may not be necessary to connect a remote turn-on lead because of the amplifier's remote sensing function.

Fuses: Three 30-amp ATO fuses protect the amplifier. Another fuse (90-amp minimum) should be placed on the +12V power wire within 18" of the battery.