Having problems with sound out of cat/krell setup

I am trying out a cat sl-1 ultimate preamp with a krell ksa-300s and the sound is very bad. The lower midrange is very harsh and overwelming. Any thoughts on what might be wrong, I can't see such a highly acclaimed preamp sounding this bad. I was using a Krell krc-2 before, Im new to the tube world as i have allways been a solid state person. Thanks in advance for any ideas on what might be wrong.
I've owned a Cat SL1 mk3 and a KSA300s...the Cat will impose less of it's own character on your system than the amp and is quite revealing especially in the midrange as it won't it cover flaws elsewhere in the system..
i can only venture to guess here......sounds like a possible tube problem in the cat. output tubes perhaps?
old krell ss amp and cat could be an awesome combo.