I have conducted a bit of an expensive and hard work experiments. I concluded that the Zx2 is an excellent transport if you use it with the correct accessory (Only). It also explains why the Zx2 spend it battery like crazy when being a transport. It is because Zx2 spends a lot of it prowess to cater toward the DC signals to not only preserve the best of the Digital signals, but also give it the best quality it needs. The worse thing is that the Zx2 needs both parts to have you witness the best of it quality. It accessory.
1/ Sony WMC-NWH10 USB Conversion Cable for Hi Res Audio Output. It has quality capacitors, resistors, and a huge processor chip on the inside. Quality shielding....etc....etc. When using this cables, there is a huge step up away from the cheap OTG cables from PHA-3 packaging or 3rd party cables of similar kind
The real deal
The trash PHA-3 cables for Walkman, and it similar low quality OTG for Walkman to digital.
Now, you ask how should you know ? First, buy authentic Sony cables as I said above. Second, the different is most seen in the size of the cables. The low quality has no inner stuffing, where as the Sony high-res has a sophisticated inner boarding. Picture from another member compare to the smaller one
To have the best quality of transporting from Zx2, you will have to modify the stock cables, and there was one member who posted it here before as well. At first look, you may think it is BS. But it is not.
http://www.head-fi.org/t/742609/sony-nw-zx2-hi-end-dap/10890#post_12400249
I did an extensive testing and criticle listening between the PHA-3 cables and this cables. There were a huge different in "inner fidelity" and "soundstage" just to name the most 2 obvious improvements. There are more weighty, impact within a tonal body of beats and plays. The vividly representing rhymes of the instruments and it energies. The bad thing is that it only has Female USB end. It also has cheap copper wires inside. Therefore, I modified my cables. Let's talk about it later.
2/ The next accessory that you would want for Zx2 as a transport will have to be the dock. BCR-NWH10
It allow you to transport quality high resolution digital signals into your DAC/amp. It also allow charging while docking and feeding external devices, so your Zx2 is always charged. You wonder why ? Here is a shot of the inside. Yes, by using these 2 accessory. You can get the best digital feeding on the go, or the best desktop digital feeding. There are no argues about this. It is just pure facts that me and a reputable member had witnessed it.
****Now, the glorified/modified**** cables. This is only a prototype. I used large AWG Solid pure quality silver for wires. Quality shielding to resist interferences, and output toward Micro-USB port. I am very happy with the result, and will be making another improved version soon.
Why do modifications ? Because we need the micro USB end, then we want to upgrade the cables for even better quality. Why not ? Beside, to make sure the inner stuffing is authentic, there is only one way....to buy authentic cables and modify it.
So far, all I can say is that Digital signals do need special cares given to have quality music as a part of the chain, and whoever think digital do not get negative affects is wrong. Example of flours and sugar to make cookies. You have bad cookies if flours and sugars are bad, you have best cookies if flours and sugars are the best. Now, imagines your Digital signals being Flours and sugar....then the chief who make cookies is your DAC....and your cookies is the final Analouges quality to output the music to your ears.
Therefore I am very happy with my improved and modified cables. I thought I would want to share with anyone who want to know more. You can disregard it if you don't want to believe it.
Now, if you want to ask more questions ? It would be why did I say Zx2 is one of the best transport ? Again, only Zx2 would bring special catering toward digital signals out at this level....a stand alone DAP that lasts for 18 hours or more....but digitally transport and it got reduced to 10 hours or so. It was also specially designed for Sony own accessory, and the best quality can only come off this combination. Would a smartphone be good for transporting ? Of course, and why not ? But portably speaking, for the best quality ? It gotta be the Sony newest gadgets and technologies.