At 2:33 in the video, he plays his Hammond for the cameras.

Mentioned in this September 15, 2008 post on the official Allman Brothers Band website forum.

Here is an excerpt from the first draft of Johnny's book:

"Duane was playing a Telly with a Strat neck and he and Gregg both had super Beetle Vox amps. I had an early '60s Fender Bassman amp Duane really liked so we took it out to California with us. As loud as we were playing at that time, the speakers in the amp were going and not quite loud enough so we put JBLs in it. I kept that amp until my friend, Butch Owens, borrowed it and it was stolen. He later replaced it with something as good as or maybe even better than what I had. It's a good amp and I still have it. I think it was one he got from Joe Walk. Paul played an A-100 with a leslie cut down to be portable. It wasn't a B-2 but it was close to it and we had a Wurlitzer piano that Gregg played. When Pete joined the band he played a Jazz bass with a custom amp. The amp belonged to a guy who lived in Decatur. . We had a Fender 12-string Gregg would use sometimes and maybe an acoustic/electric guitar. Gregg didn't play guitar very often but he wrote a lot of songs on one. He became friends with Jackson Browne when we were out there and Gregg learned a lot from him. I think they learned from each other. Gregg went through a folk phase with his writing but his style changed with different instruments. I've still got the Wurlitzer from the band and it has a story that came with it. Several of us went to a music store in L.A. and picked out this particular Wurlitzer for Paul to play since he was playing most of the Wurlitzer parts then. Actually, Gregg and Paul set up close together so they could swap between the Wurlitzer and B-3 when they needed to but Paul was primarily on the Wurlitzer. The salesman showed us how to hook it up to an amp which was essential because you couldn't play it off the little speaker that came in it. Once we figured it out, it sounded great. The Wurlitzer is still my favorite keyboard. Duane had borrowed a '59 gold top Les Paul from Tommy Compton, who still lives in Decatur, and he didn't want to give it back to Tommy. And Tommy definitely wanted it back. Eventually it worked around to Gregg trading the Wurlitzer for the guitar. The guitar was worth more than the piano but Tommy had a use for it and was trying to keep Duane from getting busted because Tommy's dad was ready to go after Duane to get the guitar back. So, the piano was sent back to Decatur and Duane kept the guitar. Of course that guitar would be worth a fortune now, certainly more than the piano is worth. Tommy eventually sold the piano to a guy who sold it to Eddie Hinton. After Eddie died in '95, his mother sent the piano back to the guy who'd sold it to Eddie and I bought it back from him a year or so later to use in my studio."

Mentioned this April 23, 2020 National Endowment for the Arts interview.

NEA: What led you to want to play the organ?

WHITAKER: I think I started playing at church, at the end of church services. My parents didn’t really want me to play it, probably because they thought it would be too loud. But my church pastor told them to let me play, and then friends gave me a small organ. After that I got a Hammond A100, then finally a portable Hammond B3, and a few others as well.

NEA: Just how portable is a portable Hammond B3?

WHITAKER: [Laughter.] Well it’s still pretty heavy but it’s definitely lighter than others.