Listening to my K1Ks from my Balancing Act with AD1 tubes, and there is nothing harsh or hard in the mid-range and the high end is well-rendered in its own space. This isn't the greatest K1K amp around, but it does a very nice job. I still prefer it from my 300B speaker amps, but that is partly a matter of taste and partly a matter of more balls to the 10 watts they are putting out. Can't you find a decent speaker amp to try out with your pair? Even taking it to an audio shop and convincing them to allow you to connect them would give you some sense of whether there is really something wrong or lacking with your particular pair.