You mean 8 watts isn’t cutting it? I guess output is in the ear of the beholder, I added a 1/2 power switch to mine so the sound guys would stop complaining about it being too loud when mic-ed into a house system. A different speaker might be louder and if you are still using the 6V6s, changing to a good 6L6 might be louder too. Certainly changing to an EL-34, KT-66 or even a 6550 would increase the output noticeably. We just did another round of testing/listening to different power tubes in a Two Stroke. The Fender fans liked the 6L6, the Marshall guys like the 6550. In the end, most everyone agreed that a good 6L6 is tough to beat.