Bob did a review of Roy's SP8 SE, I think was the model's designation, about a year back. I'd be interested also to know what the differences are between that amp, and the latest designation, but my understanding is that the major difference is that it was a 2 pc board amp in the SP8, and it's been broken down into a 3 board system in the current iteration for greater flexibility and choice of options etc.
I've been working on building one of these VTA pre amps -- sorry, I'm not even sure what model it is. : /
But back to the comparison. I'm currently using a Transcendent GG (grounded Grid) pre amp, which came highly recommended. Bob used to own one himself and had a high opinion of it too, as I recall.
But when he reviewed Roy's VTA pre-amp, he was comparing it against two commercial products costing, iirc, $3k and $6k -- and he found it superior to the former, and regarding the latter, better in some respects, but not as good in others.
So, at the end of the day, for less than a grand, to think you can have a pre-amp that holds it's own with commercially produced hi fi in the $6k range is... well... THAT is impressive!
Trying to read between the lines, and maybe I read to much into those white spaces, but my inference was that Bob thought more highly of the VTA than the TS GG.
That's a good thing, I think, because highly regarded as the GG is, there's something about it that I don't like. Now I wish I had much more experience with many more pre amps but combining my own dissatisfaction and what I read about the GG on the Transcendent forum, I have come to believe there is a certain coldness, or analytical-ness to the sound of the GG.
I'm much looking forward to having my VTA Pre finished so I can do a direct comparison of my own. I very much suspect, however, that the VTA will clobber the GG.