Onkyo A-9070

Brand: Onkyo

Model: A-9070

Technical data

• Output power: 140 W per channel into 4 ohms (2 channels)
• Frequency response: 20 Hz-20 kHz
• IECAWRAT (Advanced Wide Range Amplifier Technology)
• DIDRC (Dynamic Intermodulation Distortion Reduction Circuitry)
• Parallel Push-Pull Amplification with Three-Stage Inverted Darlington Circuitry
• Playback of 192 kHz/24-Bit HD Audio via Coaxial Inputs
• New circuit board layout with bracing to reduce vibration
• Symmetrical Right and Left Channel Arrangement
• Separate Wolfson® 192 kHz/24-bit DA converters (2 × WM8742) for left and right channels
• Four large 15,000 µF1.2-mm copper busbar capacitors for perfect grounding
• Modes of operation:
  • Power amplifier

power amplifier preamplifier

• • Preamplifier/Power Amplifier split.
• Connections:
  • 3 digital audio inputs (1 optical, 2 coaxial).
  • 3 analog audio inputs
  • 1 output "main-in" input
• Discrete amplifier for headphones
• Discrete Phono Equalizer (MM/MC)
• Speaker level control A/B
• Preamplifier outputs for audio (left/right)
• Matched, gold-plated speaker terminals suitable for banana plugs
• Gold-plated, solid-state RCA and phono inputs
• Automatic standby function
• AWRAT (Advanced Wide Range Amplifier Technology)

Comments

From the datasheet of the A-9070:

"Onkyo has declared war on distortion. You'll suddenly realize how successful this battle is when you turn on the A-9070 stereo integrated amplifier. The new DIDRC (Dynamic Intermodulation Distortion Reduction Circuitry) attenuates distortion in the high-frequency range. Closed ground loops, HICC (High Instantaneous-Current Capability) and the vibration-damping design combine to create a sound of stunning clarity and dynamics. The four 15,000-µF capacitors hold ample power reserves. Combined with a three-stage inverted Darlington circuit, the efficient parallel push-pull output stage reduces distortion to near zero. Separate Wolfson® 192 kHz/24-bit DA converters for the left and right channels enhance performance. The unit also enables playback of modern formats by supporting 192kHz/24-bit HD audio. Four modes of operation - integrated amplifier, power amplifier, preamplifier, preamplifier/power amplifier split - provide maximum flexibility for integration into existing hi-fi systems. Details such as an independent headphone amplifier, a phono equalizer, three digital audio inputs, four analogue inputs, and gold-plated audio and speaker connections testify to the highest quality. The superb craftsmanship, technical finesse, and attention to detail that Onkyo displays with the A-9070 make it a serious contender for music lovers looking for a top-of-the-line hi-fi amplifier."

"The A-9070 employs a variety of technologies developed by Onkyo to ensure optimum audio performance.

1. DIDRC (Dynamic Intermodulation Distortion Reduction Circuitry) Frequencies above 100 kHz, while inaudible to the human ear, are susceptible to clock signals and other types of distortion emanating from digital equipment. Distortion in this extremely high frequency range can create "beat interference" that affects the character or ambience of the actual sound. By improving linearity and reducing distortion in this frequency range, Onkyo's new DIDRC technology provides a noticeable reduction in noise.

2. low negative feedback circuitry. High negative feedback makes systems susceptible to the counter-electromotive force of speakers, resulting in weakened sound quality. To optimize audio quality, Onkyo focuses on improving frequency response and reducing distortion without relying solely on low negative feedback circuitry.

3. Closed Ground Loops. The A-9070 employs a sophisticated closed-loop circuit design in which each circuit is individually connected to the power supply. This reduces noise from the individual circuits and keeps the ground potential free of distortion.

4. HICC (High Instantaneous Current Capability). Rated up to 100 amps, HICC allows the amplifier to instantly neutralize the back induction energy from the speakers and send out the next signal. To achieve this goal, the current required is as high as that needed to control the impedance fluctuations of the speakers.

5. Balanced Twin-Mono Construction. The A-9070 features a balanced arrangement of amplifier assemblies for the left and right channels. Each channel has the same electrical and structural design so that the signal paths are each the same length. In this way, errors in stereo reproduction can be minimized.

Parallel push-pull amplification with three-stage inverted Darlington circuitry. In a push-pull power amplifier, the transistors of the amplifier operate in push-pull. One of the paired transistors amplifies the positive half-wave of the signal, while the other amplifies the negative half-wave. Push-pull power amplifiers are highly efficient, but can occasionally suffer from distortion. This is where the three-stage inverted Darlington circuit comes in: it reduces distortion by providing voltage stability and improving dynamic response through a low negative feedback design. Because the circuit is sensitive to oscillations, it requires sophisticated control technology. In conjunction with the push-pull output stage, the three-stage inverted Darlington circuit delivers a clear, smooth signal to the outputs.

Four modes of operation for maximum flexibility. The innovative combination of preamplifier and power amplifier functions make the A-9070 a special device. Four different operating modes can be selected at the turn of a knob. The A-9070 can be operated as an integrated amplifier, a power amplifier or a preamplifier, depending on how you want to integrate it into your hi-fi system. It is also possible to split the preamplifier and power amplifier. In this case, the preamplifier and power amplifier operate independently of each other, so that another device such as an equalizer can be connected in between.

Separate Wolfson® 192 kHz/24-bit DA converters for the left and right channels. Wolfson's high-quality DA converters help optimize the analog sound quality of the A-9070. The amplifier features two WM8742 24-bit DA converters that support sample rates up to 192 kHz. Although these DA converters can process two-channel audio via a single chip, Onkyo uses a separate chip for each stereo channel to ensure precise digital-to-analog conversion.

New Circuit Board Layout. The circuit boards in the A-9070 are not connected directly to the chassis, but are cushioned with internal braces and are attached to the front, sides, and rear. This prevents vibrations from the chassis from affecting the operation of the circuit boards.

High-quality audiophile components. Onkyo engineers have incorporated a full range of professional-grade components into the A-9070 to ensure optimal sound. Four 15,000-µF capacitors and 1.2-mm copper bus bars with very low impedance provide a consistent and reliable power supply."

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