What can I say that hasn't already been said by the vast majority of the 1,744 other posts?
PortaPro's: EXCEPTIONAL sound that blows away other "cans" I have bought over the decades from numerous companies costing HUNDREDS of dollars more... check; detailed, crisp clear highs and midrange, solid base and non fatiguing sound... check; very comfortable ... check; FUNKY looking 30 year old design that is still way cool.... check. There is only one thing I would like to add and that is this: KOSS KEEPS THEIR WORD, their customer service is OUTSTANDING and they stand by their Lifetime Warranty!
I take exceptional care of all of my AV equipment and had owned my PortaPro's since 2005 (do the math). I use them all the time and they have worked flawlessly. The only thing I ever had to do was replace the ear pads... easy fix. Well, out of the blue the left channel died. I had registered them as requested by Koss so I went on line, followed the Koss Warranty Repair instructions and sent them back to Koss. This week I received a brand new replacement pair of PortaPro headphones that should last just as long as the last pair did! And contrary to some posts, they sound just as good as my previous pair did.
Most A/V companies "Lifetime Warranty's" aren't worth the paper they are printed on. That is NOT the case with KOSS, they stand by what they sell and that is saying a lot in this day and age. So if you are looking for the last pair of audiophile headphones you will ever need: buy a pair of Koss PortaPro's, Register them online, take care of them and enjoy the ride.