At the Heart of the Award-Winning HiFi Rose RA280

The HiFi Rose RA280 is an outstanding addition to the world of Hi-Fi amplifiers, blending advanced technology with exceptional build quality to deliver an impressive audio experience that lets you truly feel the essence of the music. The amplifier focuses on the music, featuring the same remarkable GaN FET amplifier technology as its larger and more equipped sibling, the RA180.

Company History

HiFi Rose is a division of Citech, a South Korean company specializing in human touch interfaces (HTT). These interfaces are used for all business and pleasure activities and must be intuitive and robust. One of the executives at Citech is a music lover and wanted to start an audio company. He named the company HiFi Rose and set out to make products that looked interesting and cool while having the robust and easy-to-use interfaces Citech is known for. Since the beginning, HiFi Rose has proven time and time again that great sound, great looks, and ease of use can exist in one product.

* Definition Human Touch Technology, commonly abbreviated as HTT, is a term used to describe technology that is designed to mimic, replicate, or enhance human interaction. The main aim of this technology is to create a more intuitive, natural, and engaging user experience. It ranges from simple touch screen interfaces to complex AI-driven systems that can understand and respond to human emotions.

Design & Quality Build

When HiFi Rose first unveiled their RA180, the world noticed. Its steampunk-inspired front panel (Steampunk is a subgenre of science fiction that incorporates retrofuturistic technology and aesthetics inspired by, but not limited to, 19th-century industrial steam-powered machinery) and abundance of features in its new high-tech amplifier section bridged the gap between new and old. You could have an amplifier with many of the features sought after from the glory days of hi-fi but with a new high-tech, low distortion, and very efficient amplifier section.

While the RA180 was a hit, some wished they could have an option that offered the same level of performance with a more basic feature set and lower price point. If you are a digital music enthusiast or use a turntable with an MM cartridge, if your speakers are efficient and have high-quality crossover components, and if you don’t need the additional features of a product, then why pay for them? HiFi Rose listened to your needs and created a new amplifier, a simplified and more affordable version of their flagship model. 

The HiFi Rose RA280 sports a beautiful yet simple front panel and the attractive casework for which HiFi Rose is known. It looks both high-tech and purposeful with its cooling vents and logo embossed on its top panel. The color options are black or a natural metal finish that both look attractive and give users options in choosing what fits their room and system. The remote is an elegant, well-built metal unit with simple volume up and down, mute, and power buttons.

While the RA180 had an attractive but busy front panel with more options than most integrated amplifiers out today, the RA280 keeps things simple with a front panel. There is a power button, a large volume knob, bass and treble controls with a bypass switch, VU meters with a dimmer switch, and an input selector. This look keeps HIFI Rose’s industrial theme while allowing good spacing between controls.

The back panel of the RA280 is just as simple, with a well-labeled and straightforward choice of inputs and connections. There are 3 RCA auxiliary inputs for things like CD players, DACs, or legacy sources like reel-to-reel decks. There is also a moving magnet phono input and 1 set of balanced inputs for flexibility. There are trigger-in and trigger-out jacks, a phono ground, and a chassis ground. In addition, there is one set of high-quality speaker terminals per channel for outputs and one mono full-range RCA subwoofer output. Finishing out the back panel connections is an IEC power connector for your choice of power cable and a resettable breaker for system protection.

Features & Technology

When HiFi Rose decided to include bass and treble controls on their amplifiers, they wanted to design something higher-performing to allow much more control over the tone adjustment. The op-amp-based active tone control circuit in the RA280, like the RA180, has up to 15dB of adjustment at a 12dB per octave slope vs the standard gentle 6dB. This tone circuit allows more adjustment headroom in the bass and treble frequencies. In contrast, the sharper filters will enable you to adjust these frequencies without muddying the midrange or causing midrange brightness in the upper frequencies. For purists or people who love the sound of their speakers/room as is, a bypass function allows this circuit to be taken out of the loop.

The power supply inside the RA280 is specifically designed to stay efficient and high speed even under complex loads. HiFi Rose used silicon carbide FETs instead of the standard Silicon FETs in other power supplies. These high-tech devices have high voltage and heat resistance, allowing the power supply to supply maximum power while remaining efficient and cool. This well-designed power supply also applies a 2.5kW power factor correction circuit with a high-capacity condenser to maintain top performance at all loads while keeping stable and reliable.

The RA280 uses a next-gen advanced Class D design developed in-house to take the acoustic performance of traditional Class D amps to a higher level. HiFi Rose calls this tech Class AD. Class D amps are considered much more efficient than traditional Class AB amps, but most have a pretty harsh and edgy sound. HiFi Rose’s Advanced Class AD design resolves these problems with new, innovative materials. The switching output devices are the enemy of sound quality in these high-efficiency designs. Dead time and a slower switching speed can cause noise and distortions to the audio and were responsible for the noise and gritty-sounding nature of early class D designs. Using GaN over traditional silicon transistors allows the switching speed to be much faster, allowing a dead time of 1/10 of silicon transistors. This gives these new class D amplifiers a linear response, allowing them to have a natural, smooth sound quality that aligns more with class A amplifier designs.

Those who wrote off class D designs years ago due to their bright, hard treble, and unforgiving nature must listen to these new Class AD GaN FET designs. Galium Nitride transistors have changed the game regarding the sound quality attainable in class D today.

The class AD GaN FET amplifier section of the RA280 is comprised of two modules that work more like mono-block amplifiers in one chassis. These modules were specifically designed to give the RA280 a pure, analog type of sound more known with pure class-A amplifiers with efficiencies of class D. HiFi Rose applies a two-stage filtering network with -1dB in the frequency band up to 65kHz and -3dB at 85kHz. These two filters reduce carrier noise inherent in class D amplifiers, allowing the RA280 to produce clean and clear audio at all audio bands. Output is 250 watts into 4 or 8 ohms, more than enough power for almost any speaker with headroom to spare.

Performance

When we received the RA280, we were eager to see if HiFi Rose managed to incorporate the same excellent performance in a smaller, more basic design. We unpacked the unit (everything was very well done) and started connecting our speakers and sources, impressed by the simplicity and ease of use of the RA280. All the connections were well-marked, and the connectors themselves were of high quality, which gave us confidence. Knowing that we wanted to test its analog connections and the RA280's phono input, we connected the top-tier HiFi Rose RS130 streamer to the XLR input for digital streaming. We also wanted to test the RA280's built-in phono stage, so we used our SME turntable for vinyl playback. Our only real complaint is that the remote control offers only volume adjustment, mute, and power, with no input selector. We felt this was a missed opportunity, as this feature is almost standard today.

The RA280 delivers clear and dynamic sound with exceptional precision. Its capability to support high-resolution audio files, combined with its versatile connectivity options—including various analog and digital inputs—ensures a rich and enjoyable listening experience for even the most discerning audiophiles. The advanced cooling system and robust construction of the amplifier contribute to accurate performance, ensuring long-term reliability and outstanding sound quality.

For anyone looking for a clean, detailed amplifier with a quiet, noise-free background, the RA280 meets all these requirements.

Overall 

We enjoyed our time with the HIFI Rose RA280 and think it is a great amplifier. It offers all the basic functionality, giving people a more affordable option over the more feature-laden and expensive RA180. We liked the built-in phono stage and the defeatable tone control circuit. The built-in phono stage was great, only beaten by expensive separate stages. Our only real complaint was that we wished the remote had a couple more features like input selection.

We are glad that class D amplification has reached a point of equal ground with class A and A/B. With GaN technology, we think we will see many more products utilizing class D. It is excellent that HiFi Rose has embraced this technology, allowing their products to run cool and more efficiently.

If you are in the market for an integrated amplifier that embraces simplicity and sound quality, then we suggest looking closely at the HiFI Rose RA280. With its good built-in phono stage and cool running high-power class D amplifier section, we believe it will fit nicely in many people's systems.

AthensProAudio Team ©