I really dig this amp. I am looking to replace the power tubes which are 5881's. Any suggestions for 5881/6L6 tubes would be appreciated. I use this amp for blues.

I am happy with Svetlana‘s 6L6GC tubes.
I want to try the ones from www.eurotubes.com

JJ ELECTRONIC 6L6GC: This tube has the deepest, tightest low end of any 6L6 I have ever tested. The mids are full of complex harmonics. The highs are sweet and down right lush. This tube is the reason I searched out JJ Electronic when I was in Europe. I imported some of them to test before my trip and was blown away by their tone and performance. My collection of RCA, GE, Tung Sol, Philips and all the others that sit on a shelf in my tube cabinet and are now only used when other players want to A/B them to the JJ’s. When the JJ’s are biased up nice and warm they come incredibly close to that upper mid magic that my Black Plate RCA’s have but the JJ’s out do the RCA’s otherwise and especially in the low end. When over driven the JJ’s get very rich and thick. They don’t squash down and they have excellent definition and detail.