I absolutely love the 15. I am forever going back and forth from the 18 sIII to the 15. The only "issue" with the 15 I have is its a single channel amp and I have not yet founf the ideal OD pedal for it. I think I am going to pick up a tone bone hot brit or a plexi-tube and try it out.
The 15 has a great clean, and a great natural overdrive... but I need one more so I can set one up each way and AB them..
ACtually, I think I saw on the Trinty forum that Stephen is prototyping a 15 dual channel amp.... ???
AJC
(ps I want to build another Trinity amp but I really cant justify one more at this time. But I will probably do another in the future.. some day)