jakkul,
Since you mentioned that you really liked the original K550's sound, then I must recommend you look into my current AKG K553 Pro headphones. They are an
improved upon version of the K550, but look almost exactly the same! There is a TINY bit less padding underneath the headband, but I still find them to be pretty comfortable. More about their improved upon features
here, but a quick summary would be that the bass is said to be clearer and the treble is more controlled now. (I had the original K550, and they were the FIRST headphones I ever really loved, and were my third pair.)
I've had the K553 for months now, and I can say they are the BEST headphones I've ever owned, and I've owned (and returned or sold off) several, including the original K550 itself. Other headphones I've had are the Audio Technica ATH-M50X ($160) (my least favorite of all of these, though super comfortable), the Sony MDR-1A ($299), Bowers & Wilkins P7 ($399), Oppo PM-3 ($399), and the new Blue Lola ($250). (My first ever was the Sennheiser HD 598 (($146 now, though I paid $208 at the time)), but since they're open-back, I don't count them here. They were a bit tight on my sides, which is why I returned them, though other people I knew found them comfortable.) The K553 IMO outdoes them all, because of the HUGE soundstage, but also b/c of the extra clarity and neutrality of these headphones. The bass isn't strong, but it's there and you can feel it. The mids and treble are VERY clear and not subdued or confined-sounding in any way. Listening to music on them is MAGICAL! They look very premium (little to no plastic), are a good size, have folding earcups, and are quite comfortable too. More about them can be found in 2 different comparison reviews I wrote which can be found
here and
here. They are closed-back of course, just like the K550.
One thing is, even though you don't HAVE to have a good amp/DAC (amp is not enough IMO) or DAP to get the best out of any headphones, including these, I still STRONGLY recommend you get one if you don't already have one (hopefully you do). I can recommend 2 for you now that cost less than $130 (my current amp/DAC is the Oppo HA-2):
1) The
Cozoy Astrapi: I don't own it, but I'd tried it out before giving it to a friend of mine for his b'day last Fall. When I tried it out, it sounded very good and even a guy at the T-Mobile Store I was trying them out at thought they were fantastic and even took pics of the box so he could buy one himself. lol It's tiny..... like a flash drive, made of metal, doesn't have a battery so no recharging necessary (uses about 5% of your smartphone battery an hour), very easy to use, and nicely priced too.
Best price is found by buying it from a
reputable seller on eBay (free shipping). It's compatible with all phone types and PC.
2) The
FiiO E18K Kunlun: Here you have a great amp/DAC which also offers Low/High Gain options, Bass Boost (I don't recommend it though), and more power than the Astrapi can offer. It has its own battery, so you must recharge it separately. It also doubles as a power bank, so you can use it to recharge your phone. Very nice quality, like the Astrapi.
Reputable sellers on eBay (free shipping) (anyone who's sold over 100 items, or especially over 1000) are also selling it too. This is very similar to my
Oppo HA-2 in features and design.
The K553 is a "U.S. only" edition of the K55X series. If you don't live in the U.S., you can still buy them off sites that sell to other countries. (What country are you in?) For best price, I would check
here (Adorama) or else
eBay. eBay will sell internationally, though I would buy from the first link (Adorama) since they will for sure have a return policy, where sellers on eBay sometimes do not, though usually do. I don't see any eBay sellers pricing it below Adorama's price, so again, I'd recommend buying it from them. You can check to see if Adorama delivers to your country or not
here. (Scroll down to "What countries does Adorama ship to?". If buying off eBay, always read full seller description first.)
P.S. I bought
this case off Amazon for my K553. Awesome hard case!! You could buy it down the line if you want.
Hope that helps!