Abe has been using Ares 8-string bass, (not the wide neck), carvin, yamaha, fender p-bass and valley arts custom(I haven't seen it though..)..etc - he has over 50 bass from various endorse deals..
Thesedays, he's using james tyler, status graphite, yamaha, and Le duc from France exclusively.(You can see his Le duc bass on 'Sing out' w/ Ron Kenoly from hosana.)
Most of time he uses SWR amp, for the small jazz or latin gig, he usually carries SWR baby blue. When he's on tour, he uses similar kind of rigs w/ Avalon U-5 pre-amp/DI.
as you can see from other posts, Abraham Sr. started his career w/ Henry mancini, Koinonia, later on w/ Lee ritenour, Al jarreu, Hosana, Larry Carlton, Stanley clark, George benson, Chaka khan, and some movie sound track include 'Mexican'(Brad Pitt & Julia Roberts)
I saw him him several times in the studio or club, few things that make him as one of the legendary player are unique style, musicianship, and personality. If you keep listen way he plays, he has so distinctive tone, phrasing, and technique that you'll be identify him in any records without reading credit. In addition, lots of producer like to work w/ Abraham 'cause because of his warm personality, mood in the studio is always better w/ Abraham. Of course, we don't need to mention his ability to read and listen to the others.
oh..by the way, until his early 20's he use to do guitar session.