Give Kevin Deal of Upscale Audio a call. I've bought quite a few tubes from him and have always been quite happy. Here's his 12au7 page:
http://www.upscaleaudio.com/12AU7/
http://www.upscaleaudio.com/12AU7/
Preamp tubes... Psvane or Genelex?
I have a Belles VT-01 preamp that uses 4 12AU7 tubes. I was looking for a tube that will last a long time and have good dynamics. Since they can't be returned, "buy and try" does not work with this, so I am polling the audience. Any opinions are appreciated... thanks.