Wow, a steal for sure. I've been playing with mine for about a month now. Had a (stock) unit built by my friend John Weisner (from Weisner/Loesch fame). John doesn't believe in boutique parts, unfortunately, so I had to swap out the coupling caps myself (to Sonicaps). Yes, they definitely made a nice improvement in soundstage and extension, as did the NOS tubes that John sent along.
John's work is exemplary, as you would expect from someone who's been doing professional builds for 40 years or so. But I didn't pay $325 for it.
I know he is making more. E-mail me if you're interested and I'll pass it along.
Bob
