Hifi Rose - RA280 Integrated Amplifier

250 watts per channel into both 8 and 4 ohms from two GaN FET mono modules, with a moving-magnet phono stage and illuminated analog meters.

The RA280 arrived in 2024 as the more affordable sibling to the flagship RA180, at roughly half the price. It distils the same ideas into a conventional two-channel package: two gallium nitride Class-D mono modules, one per channel, fed by a 500W switch-mode supply using silicon carbide FETs and active power factor correction.

The rating that raises eyebrows is 250 watts per channel into 8 ohms and 250 watts per channel into 4 ohms — identical into both loads. That is genuine and deliberate rather than a misprint, and it tells you something real about the design. A large linear-supply Class AB amplifier doubles its power as impedance halves because it is voltage-limited. A regulated-supply Class D design like this one runs into its current limit instead, so the figure holds flat rather than climbing. In practice that means predictable behaviour into awkward speakers, not a shortfall.

The output filter is specified rather than hidden, which is unusual and worth noticing. HiFi Rose publishes −1dB at 66kHz and −3dB at 85kHz, and gives the same figures at 1 watt and at full power — a Class D amplifier whose response does not change with level is doing something right, since the interaction between the output filter and the speaker load is where switching amplifiers usually come unstuck.

Connectivity is deliberately simple: one balanced XLR, three RCA line inputs, and a fixed-RIAA moving-magnet phono stage with a ground post. A mono subwoofer output and a 12V trigger output round it out. Buyers who need moving coil, adjustable EQ curves, bi-amping or a second speaker pair want the RA180 instead. Illuminated analog meters with a three-level dimmer, a vintage-styled rotary selector and an illuminated volume knob carry the family look, in solid aluminium and rust-proof steel, in silver or black.

Features

• Two independent GaN FET Class-D mono amplifier modules, one per channel
• 250W per channel into 8Ω and into 4Ω — the same figure into both loads
• Two-stage analog output filter: −1dB at 66kHz, −3dB at 85kHz, identical at 1W and at full power
• Moving-magnet phono stage with ground terminal, fixed RIAA equalisation
• One balanced XLR input plus three RCA line inputs
• Mono subwoofer output and 12V trigger output
• Bass and treble at ±15dB with bypass switch
• 500W switch-mode supply using silicon carbide FETs with active power factor correction
• Illuminated analog level meters with three-level dimmer
• Solid aluminium and rust-proof steel chassis, in silver or black

Specifications

• Type: Integrated amplifier, GaN FET Class-D
• Amplifier Modules: Two independent mono modules, one per channel
• Power Output: 250W x 2 channels into 8Ω and into 4Ω
• FTC Power Rating: 250W x 2 channels (8Ω, 20Hz–20kHz, THD 0.07%)
• Frequency Response: 10Hz–85kHz (1W, 8Ω)
• Bandwidth: 20Hz–20kHz +0/−0dB; 10Hz–66kHz +0/−1dB; 10Hz–85kHz +0/−3dB. Identical at 1W and at 250W
• Load Impedance: 8Ω nominal; 4Ω fully supported
• Damping Factor: Greater than 250 at the speaker output
• Output Impedance: 30 mΩ at the speaker output
• Signal to Noise Ratio: Balanced 109dB; unbalanced 109dB; phono MM 85dB
• Input Sensitivity: Balanced 600mV; phono MM 5mV. HiFi Rose publishes the unbalanced figure as 600mV on its website and 300mV in the owner’s manual
• Input Impedance: 47kΩ unbalanced and phono MM. Balanced input impedance is not published
• Audio Inputs: Balanced XLR x1, unbalanced RCA line x3 (Line 1/2/3), MM phono x1 with ground terminal
• Audio Outputs: One stereo pair of speaker binding posts; mono subwoofer out RCA x1
• Subwoofer Output: Mono, 1 Vrms (2.218 dBu)
• Headphone Output: Not fitted
• Phono Stage: Moving magnet only. Fixed equalisation, approximately RIAA
• Phono Turnover: 500Hz (+13dB at 100Hz)
• Phono Roll-Off: 2.1kHz (−13.74dB at 10kHz)
• Tone Control: Bass (100Hz) and treble (10kHz), ±15dB, with bypass
• Meters: Illuminated analog level meters with three-level dimmer
• Power Supply: 500W switch-mode (600W maximum), silicon carbide FETs with active power factor correction
• Mains Input: AC 100–240V, 50/60Hz. Standby consumption less than 0.5W
• Trigger: Input 3.3V–12V; output 12V
• Remote Control: 38kHz infrared, within 10 m. Slim card-style handset supplied
• Finishes: Silver, Black
• Body: Solid aluminium and rust-proof steel
• Dimensions (W x D x H): 16.9″ x 13.98″ x 4.06″ (430 x 355 x 103 mm)
• Weight: 20.94 lbs (9.5 kg)
• In the Box: Amplifier, remote control with battery, detachable IEC power cable, user manual
• Warranty: Two years. US warranty and service are administered by HiFi Rose USA
• Note: HiFi Rose publishes no channel separation figure and no idle power consumption. It publishes three different THD figures for this model — we quote the FTC-rated 0.07%, which is the one with stated test conditions