Cayin RU6 USB DAC Headphone Amplifier

Product Information

Thanks to the Cayin RU6, it is the first time that the user can experience the analogue like sound characteristics of the well designed R-2R technology from a USB powered DAC dongle. Both technologies are not new to the market, but indeed, quite well established with a loyal following, even among modern audiophiles. By the time Cayin completed the R01 Audio Motherboard for the N6ii DAP, they noticed that the R-2R resistor ladder network could be implemented as a low power consumption DAC circuit that offers outstanding audio performance. On the RU6, this led to a degradation of sound quality since the R-2R DAC is very demanding on the incoming data integrity – with digital mobile phone volume control resulting in lower sound quality.

When off-the-shelf volume options cannot meet the high precision, low noise, low power consumption requirements of RU6, Cayin developed their own discrete resistor array volume control. As a result, OS mode offers better measurable performance, however, it can be argued that the purer signal provided by NOS mode introduces fewer artefacts, phase distortion and jitter.By long pressing Mode button you get into Settings menu where you short press Mode button again to step through settings and use Volume +/- buttons to change Gain (high/low), Oversampling (NOS or OS) mode, and Screen Backlight timeout from 10s to 60s or always on until you press Mode button again to turn on/off the display.

The three physical buttons that are located to the one side of the chassis are of good quality and offer tactile feedback. When you want to hear organic, coherent, and unmasked sounds, switching off the oversampling feature, for me, yields the best result. On the other side of the spectrum, RU6 is as amazingly competent driving super sensitive stuffs like multi drivers hybrid IEMs. With Delta Sigma audio processors, what I am hearing today is sound presentation that is very clean, detailed, resolving and analytical - and I can understand that many love it that way. The same can be said for the rest of my gears and even the normally "narrow-ish" Fostex T40RP MK3 sounded sensibly spacious.In contrast the KA3 is more extended, faster, with increased clarity and more detailed presentation but it sounds somewhat leaner while it can't touch the naturalness and physicality of the RU6. The hardware volume control buttons are backed by a sophisticated resistor ladder volume circuit, and users can select between Non-Oversampling or Oversampling mode through a simple menu setting. One of the achievements that surprised me most is that RU-6 drives successfully not only demanding iems but also demanding headphones - it drivers perfectly the Z1R iem but also the Z7M2 headphones, it also drives very well the P1 but also even the T60rp (for the headphones I used the 4. I have never imagined either stepped volume control as well as R-2R to be made possible on a USB-powered dongle design, not even a DAP.