Well, that is Ron, but the pic is from the Mk II/"Raw Power" version of The Stooges, when James Williamson took over on guitar, and Ron got 'demoted' to bass. If you look closely, you can see him playing an early 70's Gibson SB bass, which replaced the classic EB3's. Horrible junk that was indicative of Gibson's Norlin-era downslide. Ron also used a Guild JS II bass, which was derivative of the EB/SG body shape, but was a much better instrument all around. In this '72-'74 era of the band, yes, they did have Sunn backlines, Coliseums and Concerts, not always, and I'm not sure James used much of it. I've seen pics where James is playing through Marshalls or Traynors. In the original incarnation of the band with Ron on guitar and Dave Alexander on bass, while both of them favored Marshalls, I have seen concert photos with Sunn 2000s cabs in the background. As ragtag a band as they were(and also the MC5, who certainly used Sunn gear at times), I'm sure they used whatever amps they could scrounge up or whatever was given to them.