Got the PHA-2A yesterday. Been listening to it. Initial impressions with the MDR-Z1R...
Like I said earlier, I've found this headphone is a strange bird to power. Sounds great through something as simple as a smartphone, and a lot of casual listeners (although that demographic is small with this can) might leave things well enough alone with that setup... But it scales incredibly well with good power. Listening through my iFi Micro iDSD, there is fair amount of detail and seperation gained on the lower end.
Through the Sony, using the balanced connection, that low-end detail and seperation take another step forward. Like I mentioned before, the idea of a balanced vs. single connection, just scientifically, doesn't hold much water with me... With all things being equal. However I hypothesize that with the Z1R, all things are not equal. I do believe that the power source a headphone is tuned with affects things. Since a balanced source delivers more power, if the Z1R was tuned with a balanced source (and it makes sense that it would be, with the new 4.4mm standard and all), it stands to reason that the Z1R is at it's best when getting the power it was originally tuned with.
Who knows, maybe my science is off-base. What I think is what a lot of people are coming to think... that the Z1R really likes a quality balanced connection.
So the PHA-2A is staying, the Kimber 3.5mm cable is going back. I'd be very interested in a Kimber 4.4mm balanced cable, in a 1.2m length... Anybody know if Sony makes one?