-Onkyo A9070 Amplifier

Onkyo has declared war on distortion. The success of its campaign against noise is evident the moment you switch on the Onkyo A-9070 Integrated Stereo Amplifier. New DIDRC (Dynamic Intermodulation Distortion Reduction Circuitry) dampens super high frequency distortion. Closed ground-loop circuits, HICC (High Instantaneous- Current Capability), and vibration-damping construction combine to produce a startlingly pure sound across a wide dynamic range. The unit's four 15,000 ?F capacitors keep plenty of power at the ready. Efficient parallel push-pull amplification paired with three-stage inverted Darlington circuitry works at reducing distortion to almost nil. Separate Wolfson® 192 kHz/24-bit DACs for both left and right channels improve performance. The unit is also equipped with 192 kHz/24-bit HD audio playback to handle modern formats. Four discrete amplifier modes-integrated amp, power amp, pre-amp, and split pre-amp/power amp-offer flexibility when integrating other hi-fi components. Details like an independent headphone amplifier, a phonograph equalizer, three digital audio inputs, four analogue inputs, and gold-plated audio terminals/speaker posts speak of the highest build quality. The superb craftsmanship, technological refinement, and attention to detail invested in the Onkyo A-9070 amplifier make it worthy of serious consideration for those in the market for top-shelf hi-fi gear.

With parallel "push-pull" amplification, the amplifier's transistors alternately "push" and "pull" the current. In pairs, one output device (a transistor) will amplify the positive half of the waveform, while another output device amplifies the negative. Push-pull amplification is highly efficient, but can be affected by occasional instances of distortion. This is where the three-stage inverted Darlington circuitry comes in. Three-stage inverted Darlington circuitry actively works to reduce distortion by employing a low negative-feedback design to maintain voltage stability and enhance transient response. It's extremely sensitive to oscillations and requires sophisticated control technology. Together with the push-pull amplifier design, the three-stage inverted Darlington Circuitry shapes a clean, consistent signal to send to the outputs.

Boasting the combined capabilities of a pre-amp and a power amp, the Onkyo A9070 is an amplifier with a difference. At the turn of a knob, it can be configured to run in any one of four distinct modes. Depending on how you want to integrate it into your hi-fi system, you can use it as an integrated amp, as a power amp, or as a pre-amp. On top of that, you can also set up the Onkyo A-9070 in split mode. This enables the pre-amp and power amp to work separately, so you can incorporate another device, such as an equalizer.

High-quality Wolfson DACs work to optimize analogue audio performance on the Onkyo A 9070 stereo amplifier. The receiver features dual 24-bit WM8742 DACs, which support sampling rates of up to 192 kHz. Although these DACs are specified to handle two-channel audio on a single chip, Onkyo employs separate chips for each stereo channel to ensure the most accurate digital-to-analogue conversion.

Rather than being directly connected to the chassis base, the circuit boards inside the A-9070 are cushioned by internal struts and affixed to the front, side, and rear panels. This method of construction prevents vibrations from the chassis from adversely affecting the circuit boards.

To ensure optimal performance from the A-9070, Onkyo's engineers incorporated a range of professional-grade parts. Four 15,000-microfarad capacitors and an extremely low impedance 1.2 mm thick copper bus plate both contribute to achieving a smooth and stable power supply. Machined and gold-plated RCA and phono terminals ensure an extremely clean connection.

140 W/Ch at 4 Ohms, 20 Hz-20 kHz, 0.05%, 2 Channels Driven, IEC

AWRAT (Advanced Wide Range Amplifier Technology)

DIDRC (Dynamic Intermodulation Distortion Reduction Circuitry)

Parallel Push-Pull Amplification Design with Three-Stage Inverted Darlington Circuitry

192 kHz/24-Bit HD Audio Playback via Coaxial Inputs

New Circuit Board Construction with Internal Struts to Reduce Vibration

Symmetrical Layout of L/R Channels

Separate Wolfson® 192 kHz/24-Bit DACs (WM8742 x 2) for L/R Channels

Four Large 15,000 uF Capacitors

1.2 mm-Thick Copper Bus Plate for Perfect Grounding

Four Amplifier Modes (Integrated Amp, Power Amp, Pre-Amp, Split Pre-Amp/Power Amp)

3 Digital Audio Inputs (1 Optical and 2 Coaxial)

3 Analogue Audio Inputs and 1 Output

Main-In Terminal

Independent Headphone Amplifier

Discrete Phono Equalizer (MM/MC)

Speaker A/B Drive