It seems from both pictures that it belongs to Bono (or is set up to be used by Bono). That said, seems there is one to the left of Edge's Marshall amp in the "Get On Your Boots video. (Hmmmm?)
Pics in question:


Perhaps the amp in question is a 50th Anniversary VOXAC30H (Handwired)?:
http://www.wildwestguitars.com/vox/ac30h2.jpg
A Very Special AC30 that's Loaded with 50 Years of Vox Heritage!
The Vox AC30H2 handwired Heritage Collection amplifier commemorates the 50th anniversary of Vox guitar amps in impeccable style. Rather than simply reissuing old designs, Vox combines the EF86 preamp channel of 1959 with the Top Boost channel from 1963 to transport you through the golden age of Vox tone. Other features of the AC30H2 include a half-power switch, Two 12" Celestion Alnico "Blue" speakers, bass shift and brilliance switches, and a vintage-style vinyl-covered cabinet. Experience some of the best tones of the last 50 years with the Vox AC30H2 amplifier...more
Vox AC30H2 Guitar Amplifier at a Glance:
Channel 1
Channel 2
Flexible power
Vintage-style cosmetics