Just to say "Hello." I'm very active on classicspeakerpages and less so on audiokarma but have not been here before.
An "audio friend" recently got me hooked on Grado cans, then mentioned this forum.
I have not used headphones a lot but may do so now. Actually, my 1st stereo was a bare-bones system I put together in 1969: A Dynaco ST-35 tube basic amp kit, KLH Eighteen solid state tuner and some Superex 'phones. I wanted Telefunkens (rated #1 in Consumer Reports at the time) but could not find them. Koss 4A were too expensive. The Superex were pretty uncomfortable but got the job done until I could afford the $88 for a pair of AR-4x speakers.
Over the years I've had Stax Lambda, Sennheiser HD-420 and Sony MDR V-6. I still have the Senns and the Sonys. Both have required new earpads (have not tackled the Senns yet but I found instructions on the 'net).
Got the Grado SR80i for Christmas and am enjoying them with my DB Systems DB-9 headphone amp. I found a couple of references to this amp here but not much. It's a solid state unit made in New Hampshire. I re-capped mine with audio-grade capacitors and added an Alps blue pot. The combination of DB-9 and Grado is very satisfying for the jazz, classical and "classic rock" that I listen to most.
Hope to learn more about headphone listening here, although I must be cautious of the "slippery slope" leading to pricier gear!