I have sony d-ej925 I use as a transport in my portable rig,
before the dac I drove my stax 001s with it,s line out.
The player uses a battery saving mode that grabs data ,shuts down,reboots and so on , this mode is disabled when transformers are used.
I no longer use onboard batterys or the external pack,but a 5v
battery regulated to 4v[same voltage as 001]
This does improve the players sound,cleaner slightly more open.
Even without the power save mode the player consumes nothing
and I do not need 80hr playback anyway,the stax only runs for 10
on its pack.
On the subject of quality on the move,mp3 and solid state memory is a great product apart from ultimate sound quality,
I use a digital camera and they are memory hungery also but
things are moving on in leaps and bounds so pherhaps
soon cheap big memory will enable uncompresed storage
of our treasures at least that could take care of one bad link
in the chain by removing dependence on limited storage devices
and thus making it easier for smaller companys to concentrate on
the decoding and analog stages.
Obviously this is an oversimplification and there are a great
many potentialy expensive technical aspects on the R&D front.
pherhaps some one out there knows about this subject in greater
detail.
In my naiviety I would love to have ago at making something.
Oh no yet another project on the horizon,