New and Improved!
These fine little portable practice amps now have the option of a 9v wall-adapter. I have wired in a 2.1mm power jack and have a shipment of adapters due to arrive any time.
They still have the 9V battery clip for those camping trips and downtown busking excursions, but can be switched to wall-power when in a “homier” environment.
Prices vary (usually $65 to $100)
A 9V adapter with a 2.1mm positive-center plug is available as well. My stock varies, but most electronics stores will have these.