Kai Hansen

An Engl Powerball II can be seen behind Kai Hansen in these pictures.

In this article, Kai mentions he has used a 1987 Amp since before Keeper of the Seven Keys Pt 1.

At the time of purchase, it has been modified to advance the master volume and gain section. It's played on a 4x12 Marshall cabinet with a Celestion Vintage 30.

Kai mentioned to Youngguitar.jp:

Peavey's 20W small head. The distortion sound is great, and he uses it mixed with Marshall sounds. This one was played with a Hughes & Kettner 2x12 cabinet.

Kai Hansen uses the Blackstar HT-5R, as confirmed in an interview with GITARRE & BASS conducted by Lars Horstmann, where it is described as "a very good, flexible combo, with 1 × 12 ″ speaker, which can offer everything from punk to metal to reggae."

In the 2007 article "Age of Metal" by Paul Southwell for Stroppy Baby, Kai Hansen talks about his use of the Engl Straight 100 amplifier. Hansen states, "I still play my old Engl straight which is a great amp and had it worked over by a good technician and it sounds killer."

In the 2007 article "Age of Metal" by Paul Southwell for Stroppy Baby Kai Hansen confirms his use of the Marshall JMP-1 Tube MIDI Guitar Preamp in conjunction with a Marshall power amp, stating, "I’ve played with JMP-1 [rack mounted pre-amp] with a Marshall power amp for years now which is pretty reliable."

In the music video for Rise by Gamma ray you can clearly see 2551bv cabinets stacked up all around the studio. At 2:50 there is a clear shot of the band backed by cabinets and you can see Kai's Engl Straight on top of a mic'd cabinet on the left. These cabinets can also be seen in live Gamma Ray performances such as Wacken Open Air 2003.