Cayin RU3

Preamble: The good man John has kindly sent out the Cayin RU3 for review with no expectations of a positive review – and that’s exactly what he’s getting. It’s a tiny Dac/amp that can output up to 560mW into a 32 ohm load via the 4.4mm balanced output….WOW! It utilises an ESS ES9069Q Dac chip and comes in at just $99 USD. Any good you ask?? Let’s find out! I like to add on all my reviews – I’m listening with my ears, not yours. I’m listening with my gear, not yours. I’m listening with my love of audio, and not yours. YMMV….. Now let’s get our aural hands dirty! Gear: For the review, I will be throwing iems and headphones at this little guy – can he keep up?? I’ll be featuring the new Sivga Peng closed backs (review soon), my beloved Hifiman HE1000 Stealths and a last minute added surprise…… Unboxing and first impressions: It’s a lovely little black box with copper writing. Opening up, it’s a simple experience, not surprising. I received the mauve (purple) unit and it looks fantastic!!!!! The rear of the unit has a lovely spirally pattern covering it. There’s a USB-C-C cable, a manual, and a little bonus bag of Silica lollies (yes, they still taste bloody AWFUL!!!!!!!!!!!). The unit has 3 buttons on the side (top, technically I guess, coz we’re in landscape, NOT portrait…….), volume up, down and a menu button/pause. The only issue I had with the volume button was if I held up or down for more than a second (to go from 10-60 say), the unit shut down. It turned back on but you need to release the volume button before a second is up. This is just a nitpick though. And features? Holy Mackerel Batman, this little guy has more features than Uncle Barry has whisky flasks hidden around Aunt Betty’s house…… First up, there’s a Cayin Control app for your tablet or smartphone and it is easy and intuitive to use. It can do everything (and more with the User Guide) the physical unit can. It’s easy to navigate on the RU3 itself, but if you have really chubby, hairy fingers, the app is perfect. Select volume, EQ (8 presets and 1 Custom which I don’t believe is available yet as it didn’t work for me). The Audio tab covers Standard vs Hyper mode. Hyper gets you the full 560mW but doesn’t change the sound quality in any way. It also chews up more battery this way. And this doesn’t have its own battery so it feeds off your phone or tablet – keep this in mind. There is LO vs PO, Low vs High Gain, Channel Balance and multiple PCM filters to choose from. On the Device tab, choose brightness, screen timeout, theme (I love having 2 different themes – I prefer Theme 2), and a Firmware Update option which was easy to do. The final Tab is a complete User Guide which is just fantastic. As I said, this can all be done (except the guide) on the unit itself and it is very easy to use The Important Stuff: I will be going through a number of important test tracks (no set playlist this time) and talking about them with different head-fi gear. Obviously, the sound quality is a huge part of this review but the form, functionality, ease of use (UI) and build quality are just as important on dongles, Dacs, amps etc. They certainly influence the sound but if they are difficult to use, cheaply built, use poorly intuitive UIs, then the sound quality won’t matter nearly as much due to their difficulty of use. One, by Metallica is first up. I know this song backwards, sideways, and up the Khyber Pass (VERY old British humour…..sorry!). Straight up, the RU3, it’s clean, punchy dynamic and the helicopter………….it travels form way out left, around the back of my head, and then way out right. I am so familiar with these few seconds that I can reference any piece of audio gear and judge them accordingly. The Pengs are sounding bloody amazing which means this little guy is driving them with authority and ease. Guitars are clean and very resolving, the gunfire is realistic, lifelike, detailed and punchy. James sounds like he’s in front of me and Lars comes in crisp, resolving and dynamic with the drums. This is a great start for the RU-3, especially for its size!! When we hit the distorted, frenetic cacophony, the RU3/Peng combo handle it with aplomb!! There is no distortion or muddiness. It remains intact aurally and sounds great. I’m loathe to take the Pengs off but I bravely defy my own resistance and switch to my beloved Hifiman HE1000 Stealths. Up next is Passacaglia by the Gothenburg Symphony Orchestra and Lars Danielsson. This is a great orchestral-turned-jazz fusion piece. It’s dynamic, bombastic, clean, resolving and broad. Staging on the Stealths/RU3 combo is excellent. It’s all around my head again. The bass is firm, well controlled and mids are perfect for me on the Stealths. If I had to guess, the treble might be just a bee’s elbow tamed, but there is no loss of detail. It seems a tiny bit relaxed, which is not a criticism, just a (potential) observation. I recall hearing more treble brightness on this track. I love Valhalla Calling by Miracle Of Sound as a test track. It’s deep, deep, deep, grandiose, dynamic and exciting. And guess what?? It is exactly this on the Stealths/RU3. It sounds like a desktop amp (without comparing). I listen loud and I’m on 69 (out of 100) on the RU3 and it is sounding great!! It’s driving the Stealths with authority and power aplenty. I just made this decision on the fly now. I have not yet heard these iems and my review is coming very soon. Get excited!! The new Palavox Dark Knights…….. https://palavox.net/dark-knight/ $2499 USD iems being powered by a $99 dongle. Are these the best iems I have ever heard?????????? Read my review……….. Anyway, on Make Us Stronger by Ghost Rider, bass is INSANE!!! It is deeper than a prog‑metal concept album about Atlantis, narrated by Odin himself……. The punch, the hit, the smash. It’s nuts!! Resolution is also OMG level and the mids sit beautifully in the middle. Staging is also excellent, as in placement of sounds – all around. This means 2 things. The Dark Knights are MAGNIFICENT iems and also, the RU3 can drive them with power, authority, and a huge bloody smack in the face. I mentioned I haven’t listened to the Dark Knights before this review. I seriously couldn’t imagine them sounding any better, honestly. Every detail, nuance e and subtly can be heard with ease. Old Man by Beck (Neil Young cover) is a very analogue acoustic guitar driven song. Vocals on the Dark Knighgt/RU3 combo sound just lovely. Natural, realistic, clean and resolving. Guitar sounds like a real acoustic guitar with no hint of digital glare. Staging and separation are again wide, forward, back and easily pin-pointable. A wonderful listen.