This thread reminded me that I have completely forgotten about the K270s, as the DT880s and CD3000s have been taking up a lot of my listening time.
So..........I just plugged in the K270s to the Sugden and was pleasantly surprised. They are definitely not as bad as my first impressions indicated. I've been using them quite a lot to monitor some vinyl to MD recordings I'm making, and I've left them playing in another room for many, many hours. Pain in the ass, because when you take them off, the music stops. So I put them around a pillow to keep playing.
I don't know if break-in (which I've never been a true believer in) has kicked in, or my ears are hearing differently today (too many headphones to screw up my reference), but I'm kind of enjoying these things right now.
They are most definitely bass shy, but the incoherence I heard initially seems to be gone. I'm listening to the Nitty Gritty Dirt band, "Will the Circle Be Unbroken,"............a lot of instruments (guitars, banjos, fiddles, and a variety of vocalists). Instrument separation is very good, vocals have come forward a bit, whereas before, everything seemed to be coming from the bottom of a barrel. But vocals don't have the depth that either the DT-880s or the CD3000s have. But it's actually quite pleasant.
The missing bass is rather annoying, though. There's even less (a lot less) than the K501s.
I get the sense that the frequency response of these things is tilted upward somewhere in the upper midrange......and tilted downward rather drastically below around 100 Hz.
That's what I'm hearing today......of course, this could change tomorrow, depending what my new reference is.