Pros: low noise floor; incredible midrange stereo detail, imaging; great drive power/resolution
Cons: volume pot travel is less accurate than could be; front/back ergonomic concerns
This is a rewording and shortening of the Ω image DUET review. More pictures there, easier access and way bigger community here!
Yes, I've been following Cypher Labs' stuff from the beginning. Why? I'm into the same thing Jude is: game changing. The original Solo is still a fav. DAC of mine. But DUET may be the item that redefines Cypher Labs. No longer are they a DAC manufacturer. As much as I love the Theorem 720, I am not completely convinced. Why? Too much noise from the headphone output. Even my DJ1Pro could detect it. That is too much. But apart from that, 720 had all the goods: control, precision, resolution.
I have no problems with DUET's overall build. It is Rx-MKIII-B+ strong but painted to last. Fastening hardware is fast, switches are shallow, and pot is balanced. It charges via micro USB. Hell yeah. What bothers me slightly is volume pot travel. Still the pot's full travel isn't being used. Instead, only about 50-60% of pot travel decides output voltage and thus, volume levels. IEM users shouldn't have a problem as low volume levels are well balanced and noise is low, but L/R headroom is never a bad thing. And I think the last 40-50% of the pot should be used. Control is paramount for the portable user. That said, L/R balance is pretty damn good even at minimal volume settings. And there is plenty of power from there on up. I sort of wish F/R sections of the amp would sport their own in/out sections so that the DUET could be used in a pocket without cables springing from every cranny on the other side.
DUET retains the goodies while goodifying the bads. There are few amps out there with a lower noise floor than DUET. Very few indeed. IEM users will be able to use DUET with all qualms buried. Noise is very low. Control and resolution, are not. DUET exudes detail, especially from upper bass to mid-mids. You will get used to the soft mouth sounds of your favourite singer- that or trash the record for being too explicit. Warmth worms its way in throughout, but not overly much. There is plenty of sparkle up top. If you can get used to what is one of the widest stereo images out there, you will find details literally popping out of your favourite wood instruments.
But you have to find it. Insanely wide stereo images are kind of hard for the ear to suss. Why? Because we don't hear in stereo, we hear in binaural. Bleed from left to right is key for us to understand width and so on. But in the stereo world, dear me, you may not be able to find a wider image than the DUET. Vorzüge PURE II is similarly equipped. Actually, both share very similar sounds, though PURE II is slightly more detailed up top, while DUET focuses most of its imaging detail in the mids.
Of course, PURE II doesn't do balanced, and DUET does it brilliantly. It uses the same Kubikon connector the majority of American amp makers use, and so is pretty compatible around the world. If your favourite dynamic or planar headphones are wired for balanced, you may enjoy an even crazier stereo image. May. Remember, your ears are trained to hear channel bleed rather than autonomous channels. But if you can train them, you will find balanced signals even more detailed and fuller of the best parts of your music.
For reference: balanced and single ended DT880 are easily pushed to safe listening levels at L gain. I am uncomfortable using H gain with them. Higher current low-Ω headphones such as HE6 are a bit more hungry, but can be comfortably run with the DUET. IEMs are well controlled in L gain mode, with very small L/R deviation at low volumes, but achieving 95% perfection at normal volumes. All in all, the gain stage impresses me plenty.
I'm not overly excited by DUET's form factor, but dear me is it a good amp. It is one of the best out there. It's a bit big for IEMs, but it works nearly flawlessly with them. And it still has power enough for headphones. Plenty in fact. It is Cypher Labs' BAMiest product and one, that like the original SOLO, will define the do-everything headphone amp market for years to come.
This is a rewording and shortening of the Ω image DUET review. More pictures there, easier access here!