I went on the search for my first pair of serious headphones in 1990. At the time I listened to all the premium models that I could find in the Bay Area including the Grado HP1,Sennheiser HD250 and HD540, Sony MDR-CD3000, AKG K270. Unfortunately I didn’t get to hear the MDR-R10... The two that I liked were the Stax Lambda Pro and beyerdynamic DT990. They sounded the most lifelike to me and also closest to my Celestion SL-12Si speakers. I liked the beyer a tad more and it was lower priced, so I ended up buying a pair with the money I had earned working that winter break doing a temp job, helping move banker boxes at an outdoor storage unit in central California. I still have them in my collection... I have been a beyer fan ever since including the DT911, DT931. To sound with proper tonal balance in my opinion, they and the original 600 ohm DT990 need to be powered by an amplifier with higher output impedance. This is why I have the IEC setting with 120 ohm output impedance on my amps. I also like the DT770 Pro 80 ohm. I’m not a big fan of the consumer DT770, DT880, DT990, with the DT880 being the best of those 3, IMO. Beyer also makes a Pro variant of the DT990 which physically resembles my originals, and some reviews have said they’re less V-curve than the consumer variant. Here is a review with measurements I remember reading some years ago: https://headphones.reviewed.com/content/beyerdynamic-dt-990-pro-headphones-review-715 Recently I noticed that beyer had released a limited-edition DT990 Pro in all black with straight cable and they are currently available for $160 on Overstock.com. I couldn’t resist... Just received them this afternoon and upon first listen using my iPhone6 with headphone jack, I’m enjoying them. Lively presentation with good tonal balance from bass to midrange to treble with the beyer “you are there” midrange presence. There is some sibilance but by no means overpowering. Will continue listening from the phone and then switch to a Stratus.