I can't speak to the circuits, but they sound different. The 6G6-B is the one I regret selling. The blonde has a bit more mids and rocks a little more above 5. I hated the black Bright switch but found the Presence on the blonde pretty useful. For comparison, I dial the treble and presence knobs on my 2204 to ZERO (but I still have the bright cap in place and use single coils).tallchris wrote: Fri Sep 02, 2022 10:54 am How similar is the normal channel on a 6G6-B Bassman to an AA864 Bassman? Does the presence switch basically act the same as the bright switch on the AA864, so the presence all the way up is the same as the bright switch engaged?
Is it night and day? No, same ball park. But you'd hear a difference side by side for sure.
The bass channel on both is practically unusable.