My good friend and band mate Matt toured with Glenn for a couple of years just before he started doing the thing with Bonnaammaassaaa and he rolled up with his fave Ampeg rig. A valve head, possibly CL and IIRC a 4x10 and 1x15 for most gigs. Matt. Can confirm that the onstage volume, even behind the kit was loud! GH likes his rig to sing, that's for sure. His red P bass is a Nash that i know he loves to bits. Glenn accompanied Chad Smith on a drum clinic up these here parts (yes, that's the drunken pictures of Chad and i on my FB!) - surprisingly, he turned up with a MarkBass LM2 to try out and the huge 610HF underneath. It sounded good, but we both agreed it was a little 'nice' sounding at the after show errrmmm drinking session. Glenn returned to his Ampeg rig afterward. he's been seen with a Laney valve head recently, but I've no idea if he's a full time endorsee? I have a hunch he is, but i didnt look before i started typing! Never a good idea! Ha ha!