I have been listening to stock K1000 for a few days now. Today I switched to K1000 + Valhalla soldered to drivers. OMG!!! The improvement in bass is so crazy. I don't think anyone will complain of lack of bass. The stock K1000 sound like stock earbuds compared to it. My body is vibrating from the bass! It sounds very musical, there is not much to complain about, bass, speed, detail, soundstage, it is almost perfect. It actually sounds too bassy right now, but I just need to get used to it.
I'm using EMU0404 USB soundcard and T-Amp. Switching the headphone cable made a far bigger improvement than EMU vs dCS Elgar Plus DAC.