HD 555

I have some HD555s as well, had them since 2010 I think. Use them everyday for work!

I’ve had the same pair of Sennheiser HD555’s since 2006. Buy a quality product and take care of it and they last.

Hi I have the sennheiser 555, money is not that much of problem, just a normal one and I can put a little more on that. Anyone have a suggestion?

I consider discontinued HD330 (later HD465 I think) as the best on-ears I've heard, but they are pain to refurbish - no direct replacement for earpads or rubber/silicone headband strap (straps can still be in good condition though). There is a higher model HD340 / HD475 which I haven't tried, nor anything Grado. I consider the above to be better than 60Ohm Koss (not a comparison really), or the very popular HD480 Classic II, or some more current lower-mid level over-ears like HD559, but not as good as say HD555/558/579. I might pick them over HD599 though, just because I don't like the bloated tonality of HD599. So all in all, it is still not the level of hundreds of dollars, but very usable.

I compared personally with second hand HD555. https://b23.tv/rzpbhVW. I don't know what op wants but it's better to know how bad would these sound

If you have heavy headphone usage, you don't mind a bit of bulk, need a wider soundstage with actually good ANC, and need it to last, save up for over-the-ears. I have never had an over-the-ear headphone die, even though the earcups and wires (if going wired) may. This is afyer extremely rough usage. They have the best battery life too, so that's also a factor. Earpads and wires are replaceable in most though. Bose QC 35 for 8 years (replaced only because a plastic part broke and I was due for an upgrade anyways). Before that, Sennheiser HD555s for 6 years (replaced because Bluetooth and closed backs for libraries). Before that, some Razor over-the-ears headphones that also lasted for 5 years. I have a sales job and I currently travel with my QC Ultras everywhere. They don't add a lot of bulk, don't need to babied.  Sennheiser HD 350BTs at 4k seems like a steal. While I don't have personal experience with them, over-the-ears over everything.

It's rare that electronics fall into the "buy it for life" category but Sennheiser's are just fantastic.