Hi! Two years ago (maybe more?), I posted here a question about good wireless headphones. Now that I got an entry level hi-end system, I have to match it with some good headphones, the wireless are good, but not at the level of my stereo... It looks like the 580 is the way to go, I have read about it and I went to listen to some headphones (AKG, Beyerdynamics, SEnnheiser). I don't include Grado because I read they are bright, which is exactly the opposite to what I am looking for. I am satisfied with the sound of my Sennheiser wireless, so it makes sense to keep that way, although the AKG were sounding pretty much the same in terms of tonal balance, detail and sound quality. I would like to get the 600, but the law of diminishing returns seems quite steep here... Almost twice the price, for just some 1% improvement? No way! I think the 580 will fulfill my expectations. Now comes the question... How many versions of the 580 are around? I have not seen quoted in any review the "580 precision", but this is the only one I find in shops... Reviews always refer to "580" or to "580s". Is that "s" simply for the plural, or is it some certain model? Are the "580 precision" the same that were reviewed everywhere, or they released a new version? My concerns come also from the fact that the 580 are no longer part of the select "hiend" group in the Sennheiser web site. I hope you can help, thank you very much, Alberto PS: of course, at some point I will add a dedicated amp, but at the moment my dealer told me that the headphone output of the CA Azur 640 is pretty good.