The Cayin RU7 is the smoothest and most musical dongle I’ve used. It pairs beautifully with my IEMs (especially the Aria 2 + Line-T balanced cable), delivering a wide, natural stage with tight bass and airy detail. Warm, powerful, and surprisingly close to desktop quality—highly recommended.
Build & Usability
Compact, solid build, feels premium.
Runs warm after extended sessions, but not uncomfortably so.
USB-C connection is reliable across Mac, iPad, and Android.
Power draw is noticeable on mobile, but manageable.
Sound Signature & Dynamics
Signature is smooth, natural, and musical rather than clinical.
The 1-bit DAC architecture gives it an almost analog liquidity—vocals and instruments flow effortlessly.
Excellent layering and separation, even in busy mixes.
Bass is tight, textured, and never bloated.
Treble is extended but not harsh, airy without sibilance.
Pairing & Synergy
Moondrop Aria 2 + Line-T OCC balanced cable: Stage widens, bass digs deeper, micro-detail steps forward—remarkably engaging combo.
AKG K712 Pro: Surprising drive capability; RU7 holds them with authority on balanced out.
IEMs in general: Low noise floor, no hiss with sensitive sets.
Best when run balanced (4.4mm), single-ended is still good but less holographic.
Quirks & Notes
On Android, you bump into AudioFlinger bottlenecks unless using a bit-perfect app (UAPP, HiBy, etc.).
iPad and Mac (Apple Music Hi-Res) shine—bitrates lock correctly, DSD128/256 playback is gorgeous.
Switching DSD modes (128/256/512) subtly alters staging and timbre—worth experimenting with depending on headphones.
The RU7 is more than just a dongle—it’s a gateway into proper hi-fi on the go. Smooth yet detailed, musical yet precise, it consistently outperforms my expectations for its size. Pair it with quality cables and resolving IEMs, and you’re in desktop DAC territory. For anyone curious about 1-bit DACs, this is the one to start with.
