TODAY The RA180 integrated amplifier has been carefully considered, crafted and constructed to challenge contemporary expectations and deliver a near-perfect, natural sound that defies entrenched beliefs. Unique input and output options alongside user-adjustable features to suit any premium audio system ensures the use of this elegant 800W Class AD amplifier is an experience to behold.
The overall design of the RA180 perfectly complements the award-winning RS150B music streamer in its overall impression. However, its semi-exposed, retro-industrial aesthetic is one that sits at home in any premium audio system. Constructed from high-purity aluminium, the chassis houses a wealth of complex engineering inside.
The RA180 is based around a new concept Class AD Amplifier technology. Class D amplification provides higher efficiency and higher output, as well as improved noise and distortion measurements, compared to more traditional Class AB designs. However, many Class D designs in the past have suffered in sound quality, due to limitations in the digital circuitry. HiFi Rose’s state-of-the-art Class AD amplifier resolves these problems with the use of innovative new materials. The RA180’s Class AD amplifier boasts Gallium Nitride FETs as opposed to more common Silicon FET technology. The result of this design is a high-speed, perfectly accurate amplification stage with almost no dead time, allowing it to perform far more naturally, like a pure analogue amplifier.
The RA180 boasts two 200W amplifier modules per-channel. One amp is optimised for stable mid-bass and balance, while the other is designed to deliver smooth, clean power to the high frequencies, spanning up into the super tweeter area well beyond 20kHz. The result is a sophisticated bi-amplification solution from a single box, where, when the two modules per-channel are connected to a speaker’s high and low-frequency inputs separately, the driving force to the speaker is clean, controlled and directed without interference. To help control the high frequencies, the RA180 is equipped with a user adjustable active crossover. The H/F CROSSOVER section allows users to set the base high-frequency output from 600Hz to 6,000kHz for a perfect matching of the connected speakers. The high-frequency amplifier module will then support playback up-to 100kHz (@ -3dB) to help shape a wide and deep sound stage that feels natural and without limitation. Finally, the two amplifier modules per-channel can also be set to Bridge Tied Loads (BTL) mode, allowing for a single pair of speaker cables to connect to each speaker while still benefiting from 400W of rich, balanced sound.
The RA180 boasts a host of other customisable features. The Bass and Treble tone controls allow users to adjust the flat frequency response at 100Hz and 10kHz, respectively, with ±15dB gain for a fully tailored sound. There’s also the finely adjustable balance control slider to precisely set the signal split between both channels. Alternatively, the BYPASS.POWER AMP mode links the source connected to the LINE 3 input directly to the power amplifier stage without going through the pre-amplifier. This is particularly useful for home theatre applications, allowing the RA180 to power the front speakers in a home cinema system without having to manage multiple volume dials. Elsewhere the built-in MM and MC compatible phono stage – which is equipped with low-band bass TURNOVER and high-band ROLL OFF selection dials to tailor the amplifier to perfectly suit the EQ filter that each vinyl record was originally produced with – provides greater flexibility than most stand-alone phono stages are able to offer.
The RA180 features one balanced and three unbalanced inputs alongside the built-in phono stage. There’s also support for a subwoofer output, a trigger connection and two grounding points alongside the 16 speaker output terminals, which support the connection of two different sets of stereo speakers. But the wide array of features, technologies and connectivity options are all able to perform optimally thanks to the new power supply design. The power supply was developed exclusively for the RA180 and employs Silicon Carbide FET technology, with its high voltage support and heat resistance, to provide a high output in an efficient manner with low heat generation. It also responds to power delivery fluctuations well with its 2.5kW class PFC circuit, oversized capacitors and damping factor above 200. The result is a power supply that responds to the needs of the system, while always allowing the amplifier to sound as clean and natural as possible.
The RA180 is unlike anything on the market. The level of flexibility on offer is reflective of the value HiFi Rose aim to deliver at all price points, yet the innovative technology and materials used throughout the design sets the amplifier up as something capable of astonishing soundscapes. It delivers the pure, natural sound passionate music lovers expect, but in an entirely new way.