[5minastronomer]

I've been a long time user of the ER-4P and recently replaced my old set with  ER-4PTs after the former pair was lost on a business trip.  In use, I typically pair the ER-4PTs with an iPad2 (primary source), iPhone 4S and MacBook Pro using the audio-out jack in all cases.  Almost exclusively I listen to Jazz and classical music, and do not typically over-drive or amplify the music.  That being said, I do appreciate hearing 'detail' and will change the volume to get the detail.  As a result, I'm often turning down volume (too much Rock and Roll and artillery in my misspent youth) due to over-sensitive hearing.
 
So my question; will a DAC improve my listening experience, and if so, where to start and in what configuration, and will it be equally applicable to each source?   
 
And a follow-on; Assume also that my files are a mix of AIFF and Apple Lossless played using iTunes.  I'm open to other playback possibilities, but don't know where to start or the questions to ask.
 
Thanks for your recommendations and comments.
 
Art

 

[xnor]

Hmm, you appreciate hearing details but often find yourself turning down the volume. Could you please explain this a bit more?
 
Apple Lossless if fine, so you could convert your AIFF files to that as well without losing anything.

 

[5minastronomer]

Thanks for the Comments.
 
Despite having tinitis in my right ear, my hearing is otherwise acute.  Operationally, I can often find detail, such as fingers moving on a guitar's fretwork at very low volumes, but need additional volume to pull it out of the background.  However, when too loud I've got to bring the volume back down.  Track by track and often measure by measure I adjust volume when it gets too loud.
 
My hope is that better sourcing may allow me to get the detail that interests me without resorting to too much volume.
 
Thanks also for the word on Apple Lossless.
 
Art