Cayin RU7 1‑Bit DSD USB DAC/Headphone Amplifier

Turn your phone or laptop into a reference-grade source. Cayin’s RU7 delivers the fluid, organic ease audiophiles love from DSD—with the drive and dynamics you need for modern headphones—in a pocketable dongle that respects your battery and your music.

Why it matters

If you’ve tried dongles that sound sterile, hiss with sensitive IEMs, or run out of steam with full‑size cans, the RU7 is your answer. Its discrete 1‑bit DSD DAC architecture converts everything “All‑to‑DSD” before it ever reaches the amplifier, preserving tone and microdetail while keeping background noise vanishingly low. The result is an effortlessly musical presentation—smooth where it should be, incisive where it counts.

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Why Audiophiles Choose This Product

• Sound, first: The RU7’s fully balanced, discrete 1‑bit resistor‑network DAC renders timbre with a natural, analogue‑like ease while maintaining excellent transparency and stage depth. Reviewers consistently praise its organic presentation.
• Real engineering: Cayin builds the RU7 around 128 high‑precision thin‑film resistors in a differential 4‑channel DAC topology, followed by a three‑stage active low‑pass filter. All digital audio is converted to user‑selectable DSD64/128/256 before the discrete DAC, mirroring technology from Cayin’s N7 DAP.
• Practical power: Dual amplifiers operating in parallel deliver up to 400 mW into 32 Ω from the 4.4 mm balanced out (160 mW from 3.5 mm SE), with low output impedance for IEM synergy and headroom for many full‑size headphones.
• Everyday compatibility: Low 100–110 mA draw, plus native support for Android, iOS/iPadOS, macOS, and Windows (driver available), make the RU7 easy to live with across devices.
• Uniquely versatile: Both 3.5 mm and 4.4 mm sockets can be configured as fixed‑level line outputs (1.2 Vrms SE, 2.4 Vrms BAL) to feed portable/desktop amps or home systems—no extra dongles required.

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What’s Included

• Cayin RU7 portable USB DAC/Headphone Amp: Discrete 1‑bit DSD architecture, dual parallel amplifiers, 3.5 mm SE and 4.4 mm balanced I/O.
• Primary cable: USB‑C to USB‑C OTG cable.
• Adapters & accessories: USB‑A to USB‑C adapter, handmade magnetic leather case, and two adhesive metal plates for secure mounting.
• Documentation: Quick start/user information (Windows USB audio driver available from Cayin’s support page).

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Technical Specifications

Specification	Value	Notes
Product Type	Wired USB DAC/Headphone Amplifier (“dongle”)	USB‑C to host; 3.5 mm SE and 4.4 mm balanced phone/line out.
DAC Architecture	Fully balanced, discrete 1‑bit resistor network (128 thin‑film resistors)	4‑channel differential; 3‑stage active LPF.
Digital Support	PCM up to 384 kHz; native DSD64/128/256	User‑selectable All‑to‑DSD conversion.
Power Output (3.5 mm)	160 mW @ 32 Ω	Low output impedance for IEMs.
Power Output (4.4 mm)	400 mW @ 32 Ω	Drives many full‑size headphones.
Line‑Out Voltages	1.2 Vrms (3.5 mm), 2.4 Vrms (4.4 mm)	Fixed level; bypasses volume control.
Output Impedance	0.5 Ω (3.5 mm), 1.0 Ω (4.4 mm)	Helps preserve IEM frequency response.
Display	0.96" OLED, 128×64	On‑device status and menu access.
Gain & Volume	Low/High gain; 100‑step discrete resistor volume control (3 segments)	Fine control for sensitive IEMs.
Architecture/Build	Dual 6‑layer PCBs separating digital/analog	Reduces interference and preserves signal integrity.
Power Draw	Approx. 100–110 mA	Designed to minimize host battery drain.
Dimensions/Weight	66 × 24 × 12 mm; 25 g	Pocket‑friendly.
OS Compatibility	Android, iOS/iPadOS, macOS, Windows 7–11	Windows driver available from Cayin.

Notes: Frequency response, SNR, and channel‑separation figures vary slightly by output; consult your dealer’s detailed listing if needed for system matching.

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Professional Recognition

• “Organic and analogue‑like with great transparency and technicalities.” — Headfonia on RU7.
• Head‑Fi owners highlight standout timbre, stage, and power; some report mild relay clicks between tracks (a normal byproduct of the DSD/relay design) and increased host battery use—trade‑offs many accept for the sound.
• Heritage: Cayin is the personal‑audio brand of Zhuhai Spark Electronic Equipment Co., Ltd., designing audiophile components since 1993.
• Innovation: RU7 brings Cayin’s discrete 1‑bit DSD architecture—debuted in its N7 DAP—into a low‑power, dual‑PCB dongle with shared line‑out functionality, a rare combination at this size.

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The Bottom Line

The Cayin RU7 is for listeners who want portable audio without giving up musicality, headroom, or system flexibility. Its discrete 1‑bit DSD core, smart dual‑amp topology, and shared line‑out blur the line between pocket gear and serious hi‑fi, all while playing happily with your phone or computer. If you’ve been waiting for a dongle that sounds like real hi‑fi, this is the one to beat.

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