Features
Controls
Connections

Features

Stereo Integrated Amplifier: The Harman/Kardon HK 990 is a powerful stereo integrated amplifier rated at 150 watts of power per channel. The Harman/Kardon HK 990 also boasts an impressive list of advanced performance features; such as fourth-generation Real-Time Linear Smoothing (RLS IV), EzSet/EQ for room optimization, dual subwoofer outputs, and a high-current, ultra-wide bandwidth design for clear sound & more precise imaging. The HK 990 stereo integrated amplifier offers six analog stereo audio inputs & four digital inputs to ensure optimal compatibility with various audio signals.

High-Current, Ultra-Wide Bandwidth Design: The 150-watt HK 990 stereo integrated amplifier outputs a cleaner, louder, & more powerful sound thanks to its high-current, ultra-wide bandwidth (10Hz-10khz) design. By utilizing something called high-current capability (HCC), which provides the instantaneous current necessary to precisely drive & control nearly any loudspeaker system, the HK 990 can accommodate more headroom during dynamic program peaks, influencing tighter bass & a superb transient response at any volume level. The Ultra-wide bandwidth amplifier design offers improved transient accuracy & phase linearity.

RLS IV: Real-Time Linear Smoothing (RLS IV) is a feature that minimizes interference in digital-to-analog signals with two high-grade stereo analog devices (AD) 1955 DACs. The result, is richly detailed sound & noise level that remains in a non-audible frequency range with very high jitter rejection. This way, you'll always experience sonic refinement & a natural open sound stage - two benefits that should appeal to the most demanding of audiophiles.

Low Negative Feedback Design: The Harman/Kardon HK 990 employs a low negative feedback amplifier design for further improved dynamic accuracy, immeasurable distortion level, & extreme stability.

Discrete Electronic Circuitry: Rather than employing inexpensive integrated circuits, which reduce bandwidth & increase noise, the HK 990 uses completely discrete (separate) electronic circuitry to provide the highest performance level with improved linearity & less distortion.

Dual-Path Technology: Dual-path technology for pure analog or pure digital audio processing within the same product.

Cascoded Pre-driver Stage: The Harman/Kardon HK 990's cascoded pre-driver stage design considerably reduces high-frequency distortion, allowing crystal-clear high frequencies, free from any harsh sound.

Dual Differential Input Stages: The Harman/Kardon HK 990 employs dual differential input stages with their own high-voltage supply, resulting in high gain & low noise.

Dual Toroidal Transformers: Dual toroidal transformers & up to 16,000μF of supply filtering per channel will allow high channel separation & tight bass control, even with a low-impedance load.

DC Servo: DC servo ensures that the DC level of the amplifier output will stay within a specified limit at any condition.

ThermalTrak: The Harman/Kardon HK 990 stereo integrated amplifier employs a thermal tracking mechanism with ThermalTrak output stage transistors that include internal temperature sensors to bias the current of the output stage in real time.

Electronic Protection Circuitry: Sophisticated electronic protection circuitry guards the amplifier from short-circuiting or from damaged speakers & wires, without impairing sound quality, by using current-limiting or output relays.

Protection Circuits: Multiple protection circuits will switch the amplifier off in case over-current, over-voltage, over-temperature, or DC protection is detected.

Controls

Remote Control: The Harman/Kardon HK 990 stereo integrated amplifier includes an IR remote control that can operate the amplifier wirelessly, as well as compatible H/K tuners, CD players, & CD recorders.

Input Setup: Each input of the HD 990 integrated amplifier can be configured & assigned to match your system's connection types.

EzSet/EQ II (Auto Setup): The Harman/Kardon HK 990 offers EzSet/EQ II's room-equalization & system-calibration technology for simple setup. EzSet/EQ II simplifies system setup with the included Mic, while ensuring the most optimal listening environment possible, in just minutes.  EzSet/EQ II automatically adjusting sound to suit your specific room conditions, including directing sound toward listeners in the ideal seated position. EzSet/EQ II even sets speaker volume, speaker balance, & timing as well for your system's 2.2-channel surround-sound speakers. During the automatic EZSet/EQ II process, several frequency sweeps were made. Here is a brief explanation of their use.

• Far Field: The Far Field sweep is used to calibrate your speaker system (adjust relative levels, delays, and determine crossover frequency). Also, the low-frequency response of the speakers are equalized by applying a correction curve (with a range of 20Hz to 1kHz).
• Near Field: The Near Field sweep corrects the on-axis response of your main speakers. By applying Near Field sweep to each speaker, a correction curve above 1kHz is generated for each speaker.
• BassQ: If at least one subwoofer is connected, the BassQ adjusts the low-frequency response of your system, taking into consideration the acoustics of the room. The system can correct up to two subwoofers. Using two subwoofers offers the advantage of a more linear low-frequency characteristic, limiting the node effects usually found in this frequency range.

Audio Mode: The Harman/Kardon HK 990 can handle both analog & digital audio signals. It can process any input in the digital domain to equalize the signal & tailor the sound to the loudspeakers & room acoustics. You can choose from five Audio modes.

• Direct Path: Selection of the Direct Path is an analog input only option. It bypasses all digital processing (ADC, DSP, DAC) to reduce the signal path to an absolute minimum, consisting of volume control only.
• DSP Path: Selecting the DSP Path opens access to the tone-control circuits. In this mode, the analog signals are routed to the A/D Converter, Digital Sound Processor, and D/A Converter path prior to volume control.
• EQ1 LF (Low Frequency Correction): This mode can be selected once the EzSet/EQ Setup has been run. The EQ1 LF mode is the first available preset after the EzSet/EQ calibration has been carried out. This preset processes the subwoofer channels only, correcting the acoustics of the room in the low-frequency range while keeping the response curve of the main speakers unchanged.
• EQ2 LF+MF (Low + Mid Frequency Correction): This mode can be selected once the EzSet/EQ Setup has been run. The EQ2 LF+MF mode is the second available preset after the EzSet/EQ calibration has been carried out. This preset is active for the low & mid frequency response for both the main speakers and the subwoofers when it calibrates the system to the room. As a result, both the subwoofer and main speaker response curves are modified to accommodate the system response to the room. The response curve of the main speaker is corrected up to 1kHz and kept unaffected above this frequency leaving the rest of the audio spectrum unaffected.
• EQ3 LF+MF+HF (Low + Mid + High Frequency Correction: This mode can be selected once the EzSet/EQ Setup has been run. The EQ3 LF+MF+HF mode is the third available preset after the EzSet/EQ calibration has been carried out. This preset optimizes not only the main speaker and subwoofer responses to accommodate the room acoustics, but also corrects the high-frequency response of the speaker at the listening position by correction off-axis response.

Gain Adjustment: The level of different inputs source may vary. To avoid annoying level changes when switching between inputs. Gain Adjustment (from -6 to +6dB) is an option for each audio input. The processor input has a different range (-24 to +6dB) to accommodate the output levels of most processors.

Bass & Treble: Bass & Treble adjustment is accessible only when the Audio mode is not set to Direct Path. You can adjust the Bass (100Hz) & Treble (10kHz) from -10 to +10 dB.

Level Settings: The Level Settings menu permits adjusting the levels of the different speakers (+/-12dB) & subwoofer (+/-6dB) in your system.

Connections

Binding Post Speaker Terminals (A-B): The Harman/Kardon HK 990 integrated amplifier is fitted with eight heavy-duty, color-coded, gold-plated binding post speaker terminals that allow for up to 10AWG speaker wire, pin-connectors, or single banana plugs. They are not 5-way binding posts because a plastic collar prevents their use with spade lugs & they are positioned too far apart to be used with dual banana plugs. The HK 990 provides A & B speaker outputs.

HRS Link: The HK 990's high-resolution synchronization link (HRS link) lets Harman/Kardon CD players (such as the 532HD990, sold separately) lock themselves to the external clock of the amplifier to ensure a jitter-free connection. Similar to having the CD playback inside the amplifier, the HRS link carries both the system & data clocks of the amplifier, and the data stream from the CD player. As a cutting-edge feature that's fairly standard in high-end professional audio equipment, the HK 990's HRS link is designed to appease even the most discerning audiophiles.

Balanced XLR Inputs: When you're listening to audio, you want to have as little signal disruption as possible. With the HK 990's symmetric XLR inputs, you get balanced connections designed to reject both external noise (from power wiring, etc.) as well as internal crosstalk from adjacent signal cables. In addition to discriminating against noise & crosstalk, the balanced XLR inputs also allow 6 dB more signal level on the line; so ultimately you'll get a higher signal-to-noise performance.

Unbalanced RCA Inputs/Outputs: The Harman/Kardon HK 990 integrated amplifier features six gold-plated analog stereo audio inputs & two analog recording outputs.

Digital Audio Inputs: The Harman/Kardon HK 990 offers four digital inputs (2 optical/2 coaxial) & one coaxial digital output for recording. The digital outputs are assignable.

Phono Input: The HK 990 is fitted with two high-quality phono inputs for connection of turntables with an MM or MC cartridge.

2.2Ch Preamp Outputs: The Harman/Kardon integrated amplifier features 2.2-channel preamp outputs that allow the use of external power amplifiers.

Dual Subwoofer Inputs/Outputs: The HK 990 integrated amplifier provides dual subwoofer outputs to connect up to two powered subwoofers. It also features two RCA input jacks to connected the subwoofer outputs of an external surround processor.

Remote In/Outs: The stereo integrated amplifier has a 3.5mm minijack input & output for use with an external IR receiver (input) & other compatible components (output).

12V Triggers (for Sub): The HK 990 has two 3.5mm minijack outputs to send a 12-Volt DC turn-on signal to two powered subwoofers that accept 12V trigger.

RS232 Port: For future use only.

Headphone Output: When headphones are plugged into the full-size 1/4" jack on the front panel, all the speakers are automatically muted.