Hey all, Was hoping to get some advice from the local amp gurus. I've had my 6505 since about 2009, and it's had JJs in all positions for all the time I've owned it. It sounds alright, and I can decent tones from it, but it sounds a bit stifled and muffly, especially in contrast to 5150 IIs and 5150 IIIs. I'd like to open it up a bit with tube choice, and was wondering if you guys had suggestions for tubes more edgy and aggressive than the JJs? We've had 6505s in the studio with Winged Cs and Rubys, and I preferred the sound of both of those. I think the Rubys were actually my favourite, as they sounded the most aggressive.