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Integra® 2 Channel Amplifier
Integra® 2 Channel Amplifier 0
Integra® 2 Channel Amplifier 1

Integra® 2 Channel Amplifier

Model #: ADM-20.4
At a Glance
Expand your A/V receiver's audio distribution capabilities in the home theater and beyond with this powerful two-channel WRAT component, featuring auto power on and Three-Stage Inverted Darlington Circuitry.
Available in Store Only

Get to know this product.

Three-Stage Inverted Darlington Circuitry

An important upgrade to the core WRAT concept is Integra’s Three-Stage Inverted Darlington Circuitry, a low negative feedback topology featuring a discrete triple transistor array to cut distortion and boost current flow to the speakers. As well as improving efficiency, transient response, and audio clarity, discrete transistors run cooler, extending the life of your output stage for more years of trouble-free service.

All-Analog Circuitry Unaffected by Digital Noise

A standard integrated amplifier has the dual task of both processing and amplifying audio signals, and is therefore susceptible to interference from digital circuitry. As a dedicated power amp with all-analog circuitry, the ADM-20.4 is protected against digital interference. When partnered with a quality pre-processor, this unit offers all the benefits of pure analog amplification: a warm, musical, and full-bodied sound.

High Output Power Supply

From input to output, signal purity is maintained at every stage. Housed in a rigid anti- resonant steel-plate chassis and finished with a tough one-piece aluminum front panel, the ADM-20.4 is highly resistant to vibration. A massive EI transformer delivers a steady supply of power to the speakers, while two large 10,000 μF capacitors, heavy- duty transistors, and low-impedance copper bus bars work in concert to enhance the power and fidelity of your audio sources. A heavy-duty aluminum heat sink keeps the unit running cool for superior reliability and longer life.

User-Friendly Features and Better Performance

The ADM-20.4 sports banana plug-compatible speaker posts to ensure a positive connection to the loudspeakers of your choice. The unit is also equipped with selectable audio or 12 V triggers providing automatic power on/off with your home theater system plus a rearside level adjustment. A pair of line-in and line-out ports provide the multi-room capabilities to which this amplifier is perfectly suited.

  • 75 Watts Per Channel at 8 Ohms, 1 kHz, 0.08% THD, 2 Channels Driven, FTC
  • WRAT (Wide Range Amplifier Technology)
  • Three-Stage Inverted darlington circuitry to reduce distortion
  • All discrete output stage circuitry
  • Heavy Duty El Transformer
  • Two Large 10,000uF Capacitors for effective power supply
  • Low-Impedance Copper Bus Bars for Perfect Ground Potential
  • High-current, Low-Impedance Drive
  • Flat, High-Ridgity, 1/16" (1.6mm) Anti-Resonant Chassis
  • Multi-Zone Audio Capability with Line-In and Line-Out

Other Features

  • 12V Triggers Input and Output with Audio Switch
  • Banana Plug-Compatible, Color-Coded Speaker Posts
  • Input Level Adjustment on Rear Panel
  • Auto Standby On/Off Switch
  • Aluminum Front Panel With Power Light
  • Impedance Selector Switch (4-8 Ohms and 8-16 Ohms)
  • Optional Rack Mount Kit Available IRK-120-3A


Power Output (1 kHz, 0.08%, 2 Channels Driven, FTC)75 W / Channel 8 Ω; 65 W / Channel 4 Ω
THD0.08% (Rated Power)
Damping Factor60 (Front, 1 kHz, 8 Ω)
Input Sensitivity and Impedance870 mV/20 k-Ω (Unbalanced)
Rated RCA Output Level and Impedance0.87 V/270 Ω (Line Out)
Frequency Response10 Hz–100 kHz/+0 dB, -3 dB
Signal-to-Noise Ratio110 dB (Line, IHF-A)
Speaker Impedance4 Ω–16 Ω
Power Supply AC120 V~, 60 Hz
Power Consumption160 W
No-Sound Power Consumption45 W
Standby Power Consumption0.5 W
Dimensions (W x H x D)17-1/8" x 5-1/2" x 12-1/4" (435 x 139 x 317.3 mm)
Weight17.6 lbs. (8.0 kg)

Misc. Specs

Depth (in.)12.25
Height (in.)5.5
Impedance4; 8 Ohms
Width (in.)17.13
Analog Audio(RCA) Input1
Manufacturer Warranty3 Year Parts & Labor
Product Weight (lbs.)17.6
WarningProposition 65 Warning for California Residents