> HD600's warmth and relaxed vocals (the mids being farther back, as you said)

What? The 600 has the most forward mids and least warmth of any 6x0 except for maybe some versions of the 580.

my fear is that I'm going to switch between hd600s and meze 99s and forget to turn the gain switch on my amp off then rupture my eardrums

do you think something like that adapter could reduce it enough to prevent them from deafening me if that happened?

is it possible to add something like this via an adapter that works with existing headphones?

how does that work exactly?

What specific effect does that have on sound quality at similar volume levels? How does that account for warmth, clarity, and other characteristics that people frequently associate with different amp types?

Then what explains the difference most people report between solid state and OTL amps with the HD 600?

I'm sure some of it can be attributed to placebo and justifying the investment in expensive gear, of course. But enough people who otherwise know what they're talking about seem to be convinced, so it's hard to dismiss entirely. I'm not saying you have to spend thousands, but there must be at least some differences between solid state and tube amps.

Are you saying that in this particular case, the sound from the 600 at equal volume would be completely indistinguishable when plugged into either a JDS Atom or something like a Bottlehead Crack?

How so? I'm not pretending to be an expert, but I thought it seemed more plausible than some of the other claims that are often made. What does he get wrong specifically?

This is the best explanation I've heard.