The Herron is truly outstanding, and Keith Herron provides unparalleled customer service. I use the stock tubes that he very carefully tests and matches. Congrats!+1
Before the Herron, I had a Parasound JC3jr into a Herron VSTP-3A(r02) pre amp. It sounded really good, until I heard the Herron. That combination is music to my ears.
I also have a BHK. The Herron output impedance does not pair well with the BHK input impedence. Taking Keith's advice, I have the VSTP in between the two. The sound is much better, but still doesn't quite equal the Herron/Herron sound.
I'd like to point out that I purchased the VSTP used on agon, and Keith was still willing to help me.
Congrats on your purchase. I'm sure you will be quite satii