Hi-Fi Rose RA280 Integrated Amplifier

SOUND DESIGN

The overall design of the RA280 matches that of HiFi Rose’s full width streaming products. However, its elegant industrial aesthetic can complement any modern listening space. The sturdy aluminium chassis gives a reassuring weight and solidity to the build, while also doing a good job of isolating surrounding interferences from the sensitive electronic circuitry inside. The top-mounted vents bring further character to the design, while also allowing for heat dissipation from within.  

A NEW STANDARD IN AMPLIFIER DESIGN

The RA280 is based around HiFi Rose’s 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 their circuitry. HiFi Rose’s state-of-the-art Class AD (“Advanced D”) amplifier resolves these problems with the use of innovative new materials. 

ACUTELY ACCURATE

The RA280’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.  

ALL THAT POWER

The RA280 boasts separate 250W (4Ω and 8Ω) amplifier modules per-channel, delivering 500W of total system power. The power stage also makes use of a HiFi Rose-designed two-stage analogue filter to achieve the best sound quality. The LC filter helps support the amplifier’s excellent frequency response by offering -1dB attenuation in the frequency band up to 65kHz and -3dB attenuation in the 85kHz range. This technology dramatically reduces carrier noise caused by the inherent switching of Class D amplifiers, providing clearer and cleaner sound quality throughout the frequency range. This further supports the RA280’s analogue sound signature. 

CUSTOMISABLE EXPERIENCE

The RA280’s front panel offers access to Bass and Treble tone controls, allowing users to adjust the flat frequency response at 100Hz and 10kHz, respectively, with ±15dB gain for a fully tailored sound. Elsewhere the built-in MM phono stage has been purpose-designed to deliver distortion-free pre-amplification for a connected turntable.  

QUALITY THROUGHOUT

The RA280 features one balanced and three unbalanced inputs alongside the built-in phono stage. There is also support for a subwoofer output, trigger connections and a grounding post alongside the speaker output terminals. 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 first developed for the flagship RA180 amplifier. It 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 and high-capacity condenser. 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.

Specs

• AMPLIFIER TYPE
  Integrated Amplifier
• POWER OUTPUT (4Ω)
  (Per-Channel each module) 250 W
• POWER OUTPUT (8Ω)
  (Per-Channel each module) 250 W
• FREQUENCY RESPONSE
  +/- 1dB (10Hz-66kHz)
• INPUT SENSITIVITY (UNBALANCED)
  300 mV
• INPUT SENSITIVITY (BALANCED)
  600 mV
• PHONO INPUT SENSITIVITY (MM)
  5 mV
• DAMPING FACTOR
  > 250
• TONE CONTROL
  Bass and Treble
• SIGNAL TO NOISE RATIO
  (Speaker Output @ 250W x 2 Channels, Balanced/Unbalanced) 109 dB
• SIGNAL TO NOISE RATIO (MM INPUT)
  (Speaker Output @ 250W x 2 Channels) 85 dB
• THD +N
  (Speaker Output @ 250W x 2 Channels, Unbalanced) 0.007 %
• OUTPUT IMPEDANCE
  (Speaker Output @ 250W x 2 Channels, Unbalanced) 0.03 Ω
• PHONO INPUT
  MM Input
• PHONO STAGE IMPEDANCE (MM)
  47 kΩ
• RCA LINE INPUT(S)
  3
• INPUT IMPEDANCE (UNBALANCED INPUT)
  47k Ω
• BALANCED XLR INPUT(S)
  1
• INPUT IMPEDANCE (BALANCED INPUT)
  47k Ω
• SUBWOOFER OUTPUT(S)
  1
• DIMENSIONS (W X H X D)
  430 x 103 x 355 mm
• WEIGHT
  9.5 kg