Daniel, I've found that with high end audio, like a Phantom let's say, it's the very minor details that can make them so special. You heard the the bones of what the Codex is. If you spent a ton of time with it, you'd start to understand what it is. The only problem if that Pono balanced connection as the with all Ayre gear it's all about the balanced connections. I actually want to know more about the amp you have. I've heard it's a crusher. Are they still in business? Thought someone said they went under for some reason.
Back on topic, YES the Phantom's are SICK good guys. When I hook them up to my Ayre QX5 DAC/AMP, they are crazy good. The give sooooo much more micro and macro detail. Teh soundstage becomes enormous. I'm mean VERY realistic. There is so much more meat to the bones. The fabric of the music takes on a more 3D quality. Teh bass is enormous. I now realize after last nights session that the bass is there in spades and it has a LOT of quantity along with quality. There was a passage of pipe organ that was recorded in a cathedral in Europe somewhere. My body was shaking with each key stroke. It never got fatiguing on top or on the bottom. So often if there is too much bass, your ears get fatigued and you can't heard the details that you love to hear adn gives the emotion of the music.
The Phantom takes everything to a new level that I'm not sure even Dean or Jack realize. I don't know the best DAC/Amp they have used with their IEM's. I have spoken to other manufacturers and they only use a good AK or Sony DAP or a basic desktop one. So many in 2Channel don't even realize how important you amp is within the whole scope of what you hear. It's a huge deal as is the DAC as is the wire. When you deal with a true reference quality IEM like a Phantom or even others that you love, you will realize what they do best, but even better the warts become bigger too
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So far on the Phantom's I hear the upper mid boost easily on my Ayre, but it's still not even close to being harsh. It just opens up the soundstage a bit I'm thinking. I"m not an engineer like some of you guys are, lol. Hope this answers teh question of using a great feed to a great IEM.