I have been trying to fit the "Vintage Preamp" in my chain to correct the phase on my dual cabinet presets. The problem I keep running into is that it changes the tone of the amp. My guess is that this is because it's a preamp and is going to color the tone. When I reverse the phase, it makes a big difference in the tone, but makes everything kinda fuzzy (I'm placing the preamp before amp block A or B).  Just wondering if anyone has had any luck using this or if it's better to use a couple transparent EQ's after the amp block.