On Woo's site on the WA6-SE page, 6EM7 tubes can be bundled as an addon with the unit described as "the ultimate driver/power tube for the WA6-SE." I know that Jack knows his stuff and isn't interested in making broad claims, but can anyone comment that this style of tube is pretty great for the amp? With so many to choose from (the tube compatibility chart lists 7 drive/power tubes as being ok), it seems hard to nail down the "perfect tube." What does it sound like, comparatively? And even then, what manufacturer should be chosen?
As a general side question, where do you guys shop for your tubes (aside from directly from other members :P)?