1. Username: Mixpro 2. Location: Oakland, CA USA 3. Headphones: Sennheiser HD-6xx, Audio Technica ATH-R70x, Shure SRH840, Sennheiser 598, Sony MDR-V6 4. Players: Mac Mini: iTunes/Amarra and Roon; Pro Tools HD, Pono, iPod. Benchmark and Grace DACs. 5. Headphone comparison in progress. Not posted at present. 6. Yes. I imagine several members of the SF Audiophile Society would be interested. cheers.