OK, I did something here without thinking into it. I was anxious as hell. When I got the amp it was damaged in shipping so I had to retube the power tubes. I retubed it with the stock tubes which are Sovtek 5881's. While the amp has AMAZING cleans, great light crunch, bluesy/twangy tones, planty of gain, & possibly one of the best smooth lead tones ever, it's lacking in the lower-mid/lows department. There's also too much break up when cranking the amp, which from what I hear is a major problem with these 5881's. I want something more responsive & organic in the boomy department. I also want something more lush sounding when you strum chords with the gain up. I've read so much bad stuff about these 5881's AFTER retubing I'm thinking that a tube swap will fix my problem. Either that, or after hearing my friend's Splawn last night got me right back to GASing for a Splawn. I'm needing some recommendations on tubes... Can I put Mullard EL34B's in the amp? Other tubes I've heard that I should go for are JJ 6L6GC's & JJ KT-66's. I'm thinking about seeing if I can get the tools for biasing so that I can learn to do it myself. I'm also wondering if it would be a wise move to get those Sovtek 12AX7's out of the preamp section.