Cayin RU3 DONGLE DAC/AMP

The Cayin RU3 is a portable USB DAC and headphone amplifier dongle built around the ESS ES9069Q DAC and an SPV5068 RISC-V dual-core audio processor. Designed for mobile and desktop use, it supports PCM decoding up to 32-bit / 768kHz alongside native DSD512 playback while offering both 3.5mm single-ended and 4.4mm balanced outputs. Cayin combines a fully-balanced amplification stage, selectable power modes, app-based configuration, and an onboard color display into a compact CNC-machined aluminum chassis intended for IEMs, headphones, and transportable audio systems.

ESS decoding and balanced signal architecture

The RU3 uses a single ESS ES9069Q DAC with a dual-channel implementation based on ESS HyperStream IV Dual DAC architecture and SABRE HiFi technology. Support for PCM up to 32-bit / 768kHz and native DSD512 gives the RU3 broad compatibility with locally stored high-resolution libraries and streaming sources across phones, tablets, and computers.

Amplification uses two TI OPA1602 op-amps paired with two SGM8262 low-noise headphone amplifier chips in a fully-balanced quad-drive configuration. Left and right channels remain independently amplified, helping preserve channel separation and maintain output consistency through the amplification stage. In Hyper Mode, the 4.4mm balanced output delivers up to 560mW + 560mW at 32Ω, while the 3.5mm single-ended output provides up to 180mW + 180mW at 32Ω.

Power control and flexible output operation

The RU3 includes two operating modes designed around different power requirements. HYP Mode enables the RU3's higher output capability for headphones that benefit from additional current and voltage delivery, while STD Mode reduces power consumption and heat generation during everyday portable use.

Both the 3.5mm and 4.4mm outputs support either headphone output or line output operation. Phone output mode allows direct connection to IEMs and headphones, while line output mode sends a fixed-level signal to an external amplifier. This shared PO/LO implementation allows the RU3 to function as either a self-contained DAC/amp or a transportable DAC source within larger systems.

Display, app integration, and onboard control

Cayin provides hardware and software control through a combination of physical buttons, a 0.96-inch IPS color display, and the Cayin Control App. The onboard display shows playback format, gain setting, EQ status, power mode, UAC mode, and volume level directly on the device, reducing the need to navigate through source-device menus.

The Cayin Control App expands access to device functions including 100-step volume adjustment, gain selection, five digital filters, UAC mode switching, four UI themes, and 20-step channel balance control. The app also includes a 10-band high-precision lossless EQ system that allows users to save presets and make targeted frequency adjustments for individual headphones and IEMs without relying on broad bass or treble controls.

Broad compatibility across devices

The RU3 supports both UAC 1.0 and UAC 2.0 operation across Android, iOS, Windows, and macOS devices. UAC 1.0 compatibility also allows driver-free operation with supported gaming hardware including devices such as the PS5 and Nintendo Switch. Combined with selectable outputs and compact dimensions, the RU3 can function across portable listening, desktop audio, travel systems, and gaming use.

Availability

The Cayin RU3 is available in Black, Purple, and Light Cyan. Learn more on the Cayin RU3 product page.