CAYIN RU7 Portable USB DAC/Amp Dongle with 1-Bit Resistive Ladder DAC, DSD64/128/256 Support, OLED Screen, and Included Leather Case

This Cayin RU7 DAC has absolutely transformed the listening experience of my SE846 IEMs. These IEMs have always sounded good for the 4 years I've owned them, but I had no idea how much better they could have sounded all this time. This DAC drives like a beast and the sound quality is so rich and warm, with a really wide sound stage that I also hear a lot of front to back on good tracks. I always chuckled when I read people say they picked up details they'd never heard before - well, with the same IEMs I've had for years listening to some of the same music, I can now say I hear details I've never heard before. I personally like how the IEMs respond to the balanced vs. single ended output. While either output doesn't seem to change battery life, my only gripe is how thirsty the DAC is - it can pull on the battery on my iPhone 13 at a pretty good clip. I can feel the DAC get a bit warm as I listen to it, and it might just be me, but I actually think the DAC's sound quality improves as it warms up (maybe an ode to this DACs design vs. delta sigma DACs?). With that said, this is an outstanding DAC that's well worth the investment.

Estoy sin palabras, no esperaba que este pequeño dispositivo cumpliera y superara mis expectativas en cuanto a DACs se refiere (y amplificación). Tengo varios DACs, tanto de escritorio como portátiles y el RU7 les dice quítense que ahí les voy. No necesito nada más para poder disfrutar de todos mis audífonos, no tengo que batallar con frecuencias sibilantes y los bajos que genera son súper placenteros. No busquen más, esto es lo que necesitan tanto para sonido portátil como de escritorio. La salida balanceada es particularmente interesante con mis Sennheiser HD660s y la no balanceada hizo que me enamorara de mis 7Hz Timeless que ya estaban en un cajón porque mis otros dacs no los hacían sonar tan bien como el Cayin RU7. No lo duden, este es el Dongle DAC que los enamorará y los hará querer estar escuchando su música por horas.

This really surprised me with how much it changes the sound. Usually DACs and amps have little to no differences in sound and are just good for adding extra power if you need it. That’s how it should be. But this really drastically changes the sound. I tried this with 3 different headphones. Sennheiser IE900 IEMs, 64 Audio U4S IEMs, and Meze Elite headphones.For the IE900, it made the sound much darker and added a lot of low end. Which is a bad thing in this case, because the IE900 is already a very bass heavy IEM. This cut out the treble frequencies and made the bass boomy. It was not a good sound.The Meze Elite had a similar affect. But it’s not a bass heavy headphone, quite the opposite actually. Even so, it reduced the treble frequencies and made the headphones sound dead.The 64 Audio U4S however handled the RU7 very differently, and I’m not sure why. The U4S is another extremely bass heavy IEM, and in my opinion sound muffled in the mid highs. The Cayin RU7 actually opened up the treble here. It made the U4S sound much more balanced. Still bass heavy, but the treble was much better, it added crispness and detail. It’s quite a good combo actually.That leaves me unsure of how to review this. Having a DAC / amp that is only good with one of my headphones is not exactly what I was looking for. I’m also not sure how I feel about a DAC coloring the sound so much.

After a month of daily use with my MacBook Pro & iPhone, I am enjoying this dongle DAC a lot. I tried 2 other less expensive brands that had. very little impact on the music. The RU7 has a volume control and choice of Hz setting. My headphones sound better on the highest setting.The single most important aspect I was interested in, is how this DAC affects low res mp3 files. Surprisingly, it makes mp3s more airy & spacious. Bass is flat, I don't hear a boost, and the treble is very smooth. It took much of the sibilance out of my headphones.All In all, this DAC is worth the extra expense over it's less effective competition.

Went through two units, did a replacement after the first unit had noise issues. Second unit, noise issues still present. Listening to "The Night King" on high gain, there was unacceptable levels of hiss and also crackling and EMI noise galore. Quality Control check Cayin? Had such high hopes for this device as I bought it mainly to use as a line-out DAC. Forget about that. Still produced noise even just plugging my IEMs into the device using supplied USB C cable into my iPad Pro. Tried my iPhone and PC as well, other cables. Same story. NOISE! Unreal....