Definitely get the Burson HA-160. Buy it new, not used. Some of the early ones had issues. I've got the K702's and hearing them through the HA-160 is a (dynamic) match made in heaven. All discreet circuitry inside, no crappy op-amps that can distort the sound sig. Sounds as good as it should! But then I'm a Stax guy. For the same $700 I would also recommend the Stax Basic System SRS-2050. If you havent heard Stax, I would try to first before making that decision. They arent everyone's proverbial cup of tea.