Unlike many in this thread, I am a big fan of the PM-3. In fact, I think it's pretty close to a perfect portable. I prefer neutral response headphones and the PM-3s are neutral to a fault. They're easy to drive from an iPhone but sound great out of higher end amps. They're also easy to get balanced cables for, which was great because I have a Pono, a Geek Out V2, and an ALO Rx MkIII-B. I expected to use them as my go to portable cans for a long time.
However, my wife has become concerned with me using headphones that cut off too much sound from the environment in the case of emergencies, and because I wear headphones out while walking a lot. So to be respectful to her wishes, I began looking for alternatives to the PM-3. IEMs were obviously out, and I was worried I'd be stuck using earbuds and basically losing the majority of the sound quality I had become accustomed to. However, someone pointed to the Sines as an option, since they're on-ear instead of over ear and have somewhat less isolation than the PM-3. I happened to be near an Apple Store and decided to pick a pair up with the Cypher cable.
I've been putting the Sine through its paces and I can see why people prefer it over the PM-3. It has less of a neutral sound, with an ass-kicking bottom end that is palpable but not overwhelming, and with a ton of extension. The bottom end puts the PM-3 to shame. The vocals are a bit recessed compared to the PM-3, but not to an extreme degree. Even more than the sound signature, I noticed an increased clarity and superior instrument separation in the Sine. The PM-3 is great but does exhibit the wall of sound quality that some planars suffer from. The Sine is significantly better in that regard. I'm surprised at how easy it is to pick out each instrument individually but still enjoy the song as a whole. It's not analytical, even though it has qualities that might make it analytic. If there's any downside to this, it's that the wall of sound aspect of the PM-3 gave it a lushness that can be intoxicating, but I think in the end I'd take the increased detail over texture. The Sine also scales up to better gear more than the PM-3, and surprisingly sounds better single ended than the PM-3 does balanced with my Geek Out and ALO (the Pono sounds better with the PM-3 in balanced mode, but that's because the Pono only comes to life in balanced mode, IMO). I do hope that balanced cables for the Sine eventually come out though, because if it sounds this good single-ended, I know it will be even better balanced.
Anyway, the other big surprise for me was the Cypher cable. The iPhone actually sounds pretty decent with the PM-3, and although I've used external DACs with the iPhone before, I haven't really found it to be a massive improvement. I expected the Cypher cable to sound roughly the same as if I plugged the Sine into the headphone jack on the phone, slightly better but not completely different. Well, not only does the Cypher cable offer a significant improvement over the iPhone's headphone jack, it may actually sound better than any other amp I've plugged the Sine into! All the best qualities of the Sine are present, but the bottom end is even more present and extended, the imaging becomes almost 3D in its presentation. The Cypher rivals the ALO Rx Mk.III-B amp in presentation, which is no mean feat because the ALO is a really spectacular amp. There's something to be said for having a cable designed for your specific headphones and source. And no, bluetooth cannot match the sound quality on this pairing, especially since Apple hasn't even embraced high quality bluetooth audio yet. I'd say you could use the Cypher cable in place of any external DAC/amp setup for your iPhone and you wouldn't lose sound quality, or the amount of sound quality you'd lose wouldn't justify carrying around brick portable amps and/or portable DAC/amps of various shapes and sizes that have to be attached by the inconvenient camera connector.
I'm using Tyll's EQ settings from his Sine review on my iPhone (+1 dB to 500Hz and 1KHz, -5 dB to 16KHz), and I honestly cannot think of a more effective, convenient portable setup. I used to take my Pono with me, running balanced out to my PM-3, or I'd leave the Pono at home and use the ALO with my PM-3, or in a real pinch I'd just go single-ended out straight from my iPhone, at a hit in sound quality. Now I can run straight out from my iPhone and take no hit in SQ, and won't miss having to pocket an extra device or two either. Of course Android users won't get this benefit, so I hope Audeze makes a Cypher cable that terminates in USB so the Cypher cable can be used on other devices. I'll just say, if you have an iPhone, it is absolutely worth the extra $50 for the Cypher cable, especially if you're looking to simplify your portable setup.
The only complaint I have about the headphones is the lack of a hard case. I mean, for a $450 pair of headphones, you'd think they could at least include a hard case, especially since they had plenty of room in the needlessly massive box the headphones come in. I shouldn't have to spend an extra $40 on top of the $450-$500 I already spent to get a case that should have been included to begin with.
