Try a BAT VK-5i with the x-250. The BAT was used extensively in many a suite at C.E.S. and the Stereophile shows in the later '90s and was a mainstay in many reviewers personal reference systems. I am using this pre with Threshold SA-1 160watt pure class A monoblocks with glorious results. It would help if you mentioned your front end and speakers that you are utilizing.