Hi Dave,
I like 24-25" away. Andy McIntyre agreed that the placement I'm using works well. We had a great time comparing the Bent Audio TX102 to his Grounded Grid pre-amp. It was very close... I give the edge to the Grounded Grid as having a more "you are there" presentation. However, it was not a big difference. My wife thought the TX102 imaged better. I really liked it when we added Andy's tweaked ART DIO. The 7volt ouput was welcomed by the TX102. Did not have to crank the volume as far and it gave a fuller sound, better tone to vocals and piano... more body, closer to the Grounded Grid.
I can't wait to try Jackman's Foreplay. Did you get a chance to test capacitors?
Al