A Herron Audio tubed VTSP-3 Pre Amp has replaced the Audio Synthesis Passive Pre (Passion) which has been in my setup for almost 8 years. The Passion beats many active pres I have tried which included Audio Research LS2, LS3b & the ever so esoteric CAT SL1, particularly in the critical mid frequencies. The VTSP-3 comes very close to the sweetness in the Passion's mids but has bettered it in the frequencies extremes.