I have had the Odyssey monoblocks since March, 2000. I just replaced the SCE HRS line driver with a Monolithic Sound PA-1 passive/active linestage. This is a wonderful unit that comes close to the Reference Line Preeminence Series passives and has an on-demand active gain circuit, as well. Since my source has enough gain to drive the Stratos monos, I use the PA-1 in passive mode without the wall wart power supply. I am about to receive a Sonic Frontiers Line 1, which will replace the PA-1. I would like to hear what a 6922 dual triode based pream like the Line 1 does for the sound of the Stratos'.