I have made a review thread comparing the Sony MDR-1R with the Sennhesier Momentum, MDR-Z1000, Logitech UE 6000, Audio Technica ATH-M50 and AIAIAI TMA-1...
Has anyone tried feeding the D1's Tube pre-out into its own Line In?
I figured it'll be a good way to be able to use the tube without having to resort to using a separate amp.
Honestly, I don't think it would be a bad idea since you're not feeding the headphones directly from the tube output. In reality though, you'd need to select Line-in on the souce knob and you wouldn't get any sound from any other input. You'd have to perform a mod with solder and wire inside the unit to make this possible. I've thought of running wires from the tube outputs inside to the headphone opamp inputs, cutting in where the signal comes in from the DAC. I've asked Ryan about this and he said if it was that easy they would have implemented it. I would suspect some resistors or caps or something would be needed.