The Cayin RU9 is a portable tube amplifier that punches far above its weight. This compact device, housed in a sleek CNC-machined aluminum body, delivers a surprisingly rich and detailed audio experience, exceeding expectations for its size and portability. Its lightweight design makes it ideal for on-the-go listening, easily slipping into a pocket or bag without adding bulk. The inclusion of a visible vacuum tube is not just an aesthetic choice; it contributes significantly to the warm, analog sound signature that sets the RU9 apart.Beyond its attractive exterior, the RU9 boasts impressive features including multiple selectable sound modes (Tube, Tube Mer, and Solid State), Bluetooth 5.1 with support for high-quality codecs, and a comprehensive selection of input options. High-resolution audio playback is ensured by its dual AKM AK493 DAC chips. This review will delve into the performance, features, and overall user experience of the Cayin RU9, exploring whether it lives up to the hype as a premium portable amplifier.
Pros And Cons
- Lightweight (153 grams)
- Includes a magnetic leather case
- Supports three sound modes (TLIC, Mod, Solid State)
- Features a 0.96-inch display screen
- Uses a 5th generation 6P1 vacuum tube
- Supports high-resolution audio codecs (PM 768 KHz 32-bit and DSD 512)
- Includes Bluetooth 5.1 with support for various codecs (AAC, SBC, aptX, aptX HD, LDAC)
- Supports USB connection for game consoles (PS4, PS5, etc.)
- Has multiple connection ports (headphone jack, line out, USB in, USB power in, COI slot)
- Offers a long battery life (up to 4.7 hours)
- Has a premium design
- Actual battery life may vary depending on usage
Read more: Fiio K11 R2R DAC/Amp Review: A Worthy Upgrade or Redundant Luxury?
Unboxing and First Impressions
The Cayin RU9 arrived in a neatly packaged box. Opening it revealed the device itself, immediately striking with its lightweight yet premium feel. The aluminum body is surprisingly light, making it ideal for portability. The compact design, accented by the visible vacuum tube, is both elegant and functional.
Initial impressions confirm its lightweight nature; it feels comfortable to hold and easily slips into a pocket or bag. The simple and clean design is a hallmark of Cayin's aesthetic. The placement of the display and buttons is intuitive and easy to navigate.
Design and Features
The Cayin RU9 boasts a sleek, CNC-machined aluminum body. Its 0.96-inch display provides clear visibility of playback information. The device includes dedicated buttons for volume control, power, and menu navigation. Conveniently located on the side are additional buttons for music playback.
Connectivity is comprehensive, including a 3.5mm headphone jack (also functioning as a line-out), a USB-C input for digital audio, and Bluetooth 5.1 with support for various codecs (AAC, SBC, aptX, aptX HD, LDAC). A USB-C power input ensures easy charging.
Sound Quality and Performance
The Cayin RU9 offers three selectable sound modes: Tube, Tube Mer, and Solid State. Each mode provides a distinct sonic signature. The Tube mode offers a warm, analog-like sound with a full-bodied bass. Tube Mer delivers a punchier, more energetic sound, ideal for rock or electronic music. Solid State provides a more neutral and precise sound.
Across all modes, the sound is detailed and clear, with a wide soundstage. The vacuum tube (6P1) adds a unique warmth and character, especially noticeable in the midrange and treble. The device's dual AKM AK493 DAC chips ensure high-resolution audio playback.
Battery Life and Accessories
The Cayin RU9 is powered by a 2000mAh battery, providing up to approximately 4.7 hours of continuous playback. Actual battery life will vary depending on usage patterns and volume level. It also supports DC power input for extended use.
Included accessories include a magnetic leather case, providing both protection and a convenient way to attach the device to a phone or bag. A short USB-C to USB-C cable and a USB-C to USB-A adapter are also provided.
Conclusion
The Cayin RU9 is a compelling portable amplifier. Its lightweight design, high-quality sound, multiple sound modes, and extensive connectivity make it a versatile choice for audiophiles on the go. The inclusion of the vacuum tube adds a distinct character and warmness to the audio experience.
While battery life could be slightly longer, the overall package is impressive. The combination of portability, sound quality, and thoughtful design makes the Cayin RU9 a top contender in the portable amp market. It's a definite recommendation for those seeking a high-quality, yet portable listening experience.
