And now for something completely different. I don't subscribe to the "all Krells are bright,(etc.)". I think the KSA 250 might even be a bit warm. If you want to balance the sound that attracted you to the KSA 250 in the first place with some tubes, I suggest a Sonic Frontiers Line stage. A very neutral tube stage that has a low output impedance, is DC coupled (Krells rightly or wrongly are reputed to be sensitive to DC offset), offers true balanced inputs and outputs, a nice remote and is built as well as a Krell. BTW, I've been using c-j pre/power on Thiels for many years.