We will await your comparison of Don's latest preamp to your BAT preamp, which even at pretty much twice the cost of Don's preamp, will be worthy comparison. There is magic in his 6SN7 tubes! I had a pair of Joseph Audio RM25XL speakers that for some odd reason I parted with, selling the to Don Sachs, actually.
I heard the Pulsar's at an audio show powered by a Rogers tube amp and the bass response simply defied belief... similar in performance to the Dynaudio C1's, but with better LF response.
Asghar,
The upgrade of Don's new caps and the rewiring of the preamp to accommodate the more potent 6BY5 rectifiers is something your system would benefit from... it is an easy 10-15% improvement... the instruments much greater spatial definition. I will be in touch with you after Don's tube amp is run in properly. We will have fun comparing it to your fine Quicksilver mono block amps. :-)