Thank you Tpsonic and Spencer. At one time I had Krell monoblocks and I was told that if I was going to use a tube preamp, I should send the amps in to get the transformer taps changed (?). Anyway, I've listed a want ad for a pair of VAC PA 160 mk IIs. I like the reputation, style and high power of these units because I have B&W 801 Matrix series 3 loudspeakers. Even though they are large, I'm using them in a small to medium space in a nearfield (about a 7 foot triangle) listening setup. And, I really like the style of the Audio Research SP 9, or SP 14 (I have a ReVox tape deck and a Studer reel to reel).