Nice poweramp and nice preamps too! You should have a lot of tonal ground covered there. If you get a chance to open that 500 up at real volume,it's awesome!
I just got a modded MESA D180 and run the Ada mp1, superlead, and a Myasnikov IIC+ through it for pre’s.. insane sound at todays practice. Killed my Fryette PS100. Congrats on the new tone we all search for