Originally Posted by TheMarchingMule
The 5G/5.5G supposedly use different DACs.
Nope, all three use the WM8758 (or WM8978 which is basically the same chip).
They should sound the same, unless of course Apple changed the caps/inductors in the signal path, which might have happened, but I really doubt it.
Remember when the Cardas V2 (gray) cable came out for Sennheiser headphones and everybody was like "ooh, wow, this sounds so much better than V1 (blue), more mids, better highs, etc etc" and then Colleen Cardas had a laughing fit during an interview and said it's the exactly same cable but with a different color jacket.
I think this is the same situation, same DAC in all three.