Key benefits Broad tube compatibility: supports replacing tubes including 6J1 6J2 6J3 6J4 6J5 6A2 6K4 6K5 6AK5 6AU6 6BA6 6BD6 EF93 6K7 GE5654 etc. This enables flexible use with a wide range of compatible equipment. Simple power interface: power socket is DC3.5/5.5*21. This allows use with common DC adapters that match the specified connector size. Reliable power requirements: designed for DC1216V input, 1A or more. DC12V 1.5A supply is recommended for performance. Ready to use tube configuration: includes a tube 6j3 (The tube is disassembled), facilitating inspection or replacement as needed. Practical for maintenance and experimentation: suitable for use in tubebased projects, repairs, and testing scenarios where tube swapping is needed. Specifications at a glance Tube support: 6J1 6J2 6J3 6J4 6J5 6A2 6K4 6K5 6AK5 6AU6 6BA6 6BD6 EF93 6K7 GE5654 etc. (the tube list may continue as indicated) Power socket: DC3.5/5.5*21 Power supply: DC1216V, current 1A or more (DC12V 1.5A supply power is recommended) Tube: 6j3 (The tube is disassembled) 23 use scenarios Scenario 1: Repairing or upgrading vintage tube audio equipment. When a device uses one of the supported tubes, this unit allows convenient tube swapping and compatibility testing. Scenario 2: DIY tube amplifier project or bench testing. Use the device to experiment with different tubes from the supported list and evaluate performance in a controlled, portable setup. Scenario 3: Maintenance of vintage radios or amplifiers. Use it as a compatible power and tube replacement option to restore operation or verify tube substitutes without replacing the entire unit.