Auto-Bias-Kit Stainless-Steel Dyna-70 Ultimate Upgrade Amp $2,150.00 Black Dyna-70 Ultimate Upgrade Amp w/ Alum Face Plate $2,250.00 Nickel Dyna-70 Ultimate Upgrade Amp $2,400.00 Brown Dyna-70 Ultimate Upgrade Amp with Tube Cage $2,250.00 Dyna-70 Ultimate Upgrade Kit w/ Automatic Bias Module $489.95 Dyna-70 Ultimate Upgrade w/Auto Bias Indicating Tube Status $60.00