After only a week of playing through my recently acquired DRRI I finally had to change the speaker. The stock Jensen C12K is way too bright for my liking. I had an extra Celestion G12H30 in the basement and performed the swap this morning. Right away those ice-pick highs are gone. I need to play through the H30 for a week or so to decide if it's going to stay in there. Some new tubes arriving Thursday. I checked out the bright cap at C10 while I had the chassis out. I don't know yet if I'll have to go that far to mellow this amp out.