Engl E645 Powerball version 1 The Engl E645 Powerball is my current gigging and rehearsing amp. I'm currently using the amp with two power tubes pulled, for 50w output. It's still very loud - I don't go much past halfway on master volume B for solo boosts. I also lined the back with white polypropylene plastic - this dramatically increases the amount of backlighting provided by the factory installed red bulbs behind the tubes. Check out the official ENGL website at www.engl-amps.com