[disgruntleddave]

Does anyone know if the HD-600s have had any major changes in specs (drivers, wires, etc) over the last number of years?
 
With them being either discontinued, or in between production runs, my order for a pair was cancelled and I'm looking at picking up a used pair. I just wanted to make sure that I wouldn't be missing out on any big improvements from the last few years.

 

[xaval]

The only difference I am aware of, is the change of velours.
 
The older ones are a bit thicker as in your ears are a bit further away from the drivers. I have an old production serial number and have these older pads - still as new after... I don't remember how long, but like some 12-15 years
 
There is a slight change in perceived sound, obviously. It has been discussed a while back on a older thread and I'm not aware of anyone beign able to get the "older" ones - now 600 and 650 share the same velours. I think that's about it.