Rega – Osiris Reference Integrated Amplifier

Dual-Mono Rega Osiris Drives Speakers with Ease: U.K.-Built, 162Wpc Integrated Amplifier Features Single Stage of Power Amplification Between Input and Speakers

Osiris, Rega’s flagship integrated amplifier, may not rule as a god of the underworld but it certainly reigns when it comes to producing seductive audio performance and ultra-clean signal paths. Housed in a custom CNC-machined aluminum case, the dual-mono design boasts minimalist-minded high-gain power-amp and passive preamplifier circuit technology to deliver everything from massive crescendos to graceful, subtle nuances with purity, verve, and authority. Outputting 162 watts into eight ohms (250 watts into four ohms), Osiris drives even difficult speakers with a finesse, ease, and confidence that allow notes to properly decay, chords to bloom, and voices to soar. As such, Osiris boasts degrees of engineering, build quality, and technology befitting an advanced scientific laboratory component.

To begin, the 56.4-pound unit uses low-distortion high linearity and a bandwidth common-base voltage amplifier driver stage. Such symmetrical circuit topology provides the voltage swings that enable the Osiris to perform with minimal distortion. In addition, eight Sanken 200-watt output transistors are utilized in a triple high-current output stage. Osiris’ cascoded differential input amplifier uses two low-noise LED referenced current generators, while the open-and-closed loop feedback levels and gain bandwidth components offer a tight, controlled soundstage, especially at low-frequency levels. Nichicon capacitors, electrolytic capacitors bypassed with polyester capacitors, and low-inductance film SM power resistors in the output stage are also onboard.

For the power supply architecture, two low-noise 400VA toroidal transformers with high-grade, fully bonded core material arrive mounted to the chassis via an innovative technique that eliminates noise from being transferred from the transformers to the case when the latter operate under arduous mains conditions. Moreover, the transformers combine with 40,000 micro-farads of Rega K-Power smoothing capacitors per channel, generating enough current to drive even the hardest of loads. All the power supplies use fast recovery rectifier diodes throughout. Osiris’ input and low-level driver stages get fed from a regulated symmetrical tracking power supply with a low-noise voltage reference, providing fully stabilized low-noise voltage. The dedicated audio power supplies only feed the audio circuits as the input switching, display, and micro controller and protection circuits have their own dedicated supplies.

Electronic thermal DC protection, short circuit protection, a passive volume control, and a high-end aluminum remote control further define a power amplifier that functions as a paradigm for Rega’s four-decade-plus track record in audio – as well as a reference foundation for any system fortunate to have it in the chain. 100% Music Direct Satisfaction Guaranteed.

“[What] makes the Rega [Osiris and Isis] so special – so natural and magical at the same time – is that they continually supply streams of contextual information that helps make the music more intelligible, richer in meaning.”
– The Absolute Sound

“Used as a pair (surely the way most [Osiris and Isis] will be bought), this is a cracking combination that sounds massively entertaining without being particularly showy about the way it delivers music.”
– What Hi-Fi?