watching season 3 episode 8 there's Sonny Landreth recording a session, I think its with his dumble, i can't make out the amp since there's only the back side of it, but it sounds close enough.
just saying
backside of the amp has writing on the "dumble" side too
I saw this episode a couple months ago and thought the same thing. Couldn't make it out exactly either. IIRC it was a black head with a silver chassis.
Sonny owns an HRM 50/100W w/ a tan cab, and usually plays thru his Bandmaster cab. Although he has performed with a Bludotone as well. Sonny could make a radio shack amp sound great.
The first person I know that saw him live when he first made the scene in Nashville in the late 80's said he was playing through a really hold Peavey SS amp. He said he sounded amazing.
I was lucky to get an impromptu slide lesson from Sonny at a recording session in about 1990. Nice guy.