Headphones and amp questions


I am contemplating getting a set of headphones and headphone amp, again.

In the past when I considered this, the Senn 600's and the Grado RS-2's seem to be the leaders in my research, as well as some AKG's.

First question, the Senn's are open back and can be easily heard by others from what I have read, is this true? Are the Grado's quieter than the Senn's in this respect?

I don't know anything about headphome amps, I was thinking about the Musical Fidelity X-can, is this a good choice?

Will it hinder the music much if I get a long extension for the headphones? I would like to sit, comfortably, a good 14ish feet away.

Any and all opinions will be appreciated.
brianmgrarcom
Actually, you can do as I did and buy new from a poster here on Agon for about $240.00. They came thru just fine and I'm very happy with them. My other recent phones were Stax Lambda Pro Jr.
I use the X-Cans v.2 with the HD600's, and can recommend the combo. The MF amp won out over an Antique Sound Labs MG Head DT during my in-home auditioning as being more dynamic, extended, and neutral, if a little more "in-your-ear" up-front in presentation. I chose it because I value the more accurate, less colored sound. (Both of these tubed amps did a better job than the output jack on a CD player.) When I previously auditioned the RS-2's on a McCormack Micro headphone amp, I found the Grado's much less comfortable, and too bass-heavy and slower-sounding. Some might call them tonally "richer", and I can sympathize because the Senn's do tend toward detail over fullness, but I favor their overall balance and resolution. I am thinking of trying out the new Cardas replacement cordset for the 600's, which is a standard 3 meters in length, but haven't used an extension.
I have tried the Grados and Sennheisers with the XCan and XCan 2 amps, and did not like either combo that much. I finally settled on the 600s for phones and a Headroom Max for the amp. I have not yet found anything better.