Forget the Audible Illusions, Art Ferris has the worst service i've ever experienced. Conversely, consider a Quicksilver Full Function Tube Preamp. Mike Sanders is great! His pre is built like a tank, has tube rectification (older one), many inputs/two outputs/ many features, built-in tube Phono Pre too.
Wright Sound preamps too (rare).
Wright Sound preamps too (rare).