Cayin RU9 Tube/Solid-state DAC Amplifier

Cayin RU9 – Nutube 6P1 Tube & Solid‑State DAC/Amp

The Cayin RU9 pairs Nutube 6P1 vacuum tube charm with precision solid-state circuitry in a sleek, palm‑sized design—ideal for today’s discerning audiophile.

Triple Timbre Output (3.5 mm & 4.4 mm)

Dual headphone outputs, each with three selectable timbres:

• Classic Tube – Uses Nutube 6P1 without global feedback, delivering rich harmonic distortion (THD ≤3.1%) and warm, nostalgically “tubey” tones.

• Modern Tube – Adds global negative feedback, offering smoother, cleaner warmth with tightly controlled THD (~≤0.6%).

• Solid‑State – Driven by op‑amp ICs for fast transients, neutral reproduction, ultra‑low THD (≤0.008%), and pristine clarity.

Dual AKM AK4493SEQ Mono DACs

Two AK4493SEQ DAC chips decode left and right channels separately. This results in superb channel separation and low crosstalk, delivering high-resolution clarity in every note.

16‑Core XMOS XU316 USB Engine

Supports UAC1.0/2.0 compatibility—plug-and-play for Macs, PCs, Android, iOS, and consoles—with full PCM (up to 32-bit/768 kHz) and native DSD (up to DSD512) support.

Three Power Modes & Hyper Mode

• Battery (2000 mAh): Up to 4.7 hrs on single-ended solid-state; slightly less with tube modes.

• USB-Powered: Streamlined operation without charging.

• DC External Input: Unlocks Hyper Mode—boosted current/voltage for stronger headphone drive:

  • Balanced DC: 1 000 mW (32 Ω) / 1 170 mW (16 Ω)

  • Single‑ended DC: 420 → 610 mW depending on impedance

Battery-powered THD and power output specs highlight the shift between battery and DC modes.

Bluetooth & S/PDIF Connectivity

Built-in Qualcomm QCC5125 chipset delivers Bluetooth v5.1, supporting LDAC, aptX HD, LL, SBC, and AAC. S/PDIF I/O is also available for integrating with digital audio sources.

Robust & Practical Design

• Magnetic rear panel and hand-stitched Cayin leather case provide secure attachment and premium look.

• Slim (15 mm), CNC-machined metal chassis weighing just 150 g.

• Premium details: vibration-isolated Nutube, knurled volume knob, adjustable 0.96″ color LCD, and multi-color LED indicators.

• Ergonomic L-shaped USB cable included.

Ideal For Every Setup

• Portable USB DAC/Amp: Full UAC compatibility and ASIO for high fidelity playback.

• DAC/Preamp: Use via S/PDIF for hi-res system integration.

• Wireless Input: Bluetooth connectivity lets you enjoy HD streaming from any device.

Why the RU9 Stands Out

• Combines warmth of tube, clarity of modern tube, and precision of solid-state—all in one ultra-portable unit.

• Tuned for everyday and desktop use with fast charging (QC3.0/PD2.0) and versatile power modes.

• Exceptional specs: high dynamic range, low noise, and channel separation across modes, ensuring reference-grade audio wherever you go.

Cayin RU9 is the new-age audio dongle that caters to nostalgia seekers, detail lovers, and purists alike—delivering high-end performance in a compact, thoughtfully engineered package.