Key features and specifications 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) Tube compatibility: Product supports replaceable tubes including 6J1 6J2 6J3 6J4 6J5 6A2 6K4 6K5 6AK5 6AU6 6BA6 6BD6 EF93 6K7 GE5654 etc. Key benefits Flexible power options: Operates from a DC supply in the range of 12 to 16 volts, requiring 1A or more. The recommended supply is DC 12V with 1.5A for performance. Replaceable tube design: The unit uses a 6j3 tube and is designed to accommodate a wide range of compatible tubes, enabling tonal and performance adjustments through tube swapping. Broad tube compatibility: Supports many common tubes (listed), giving you multiple options for voice, gain, and response without changing hardware. Simple upgrade path: With a disassembled 6j3 tube and a broad tube compatibility set, you can experiment with different tubes to tailor the device to your project needs. Clear specifications for integration: The power and socket details are explicitly stated, helping you plan power supplies and connections accurately. What makes it stand out Wide compatibility: The ability to the tube with a broad list of compatible tubes provides flexibility for tone shaping and project . Practical power guidance: Clear recommendation for power supply (DC12V 1.5A) helps ensure stable operation and better performance. Tubebased versatility: The combination of a 6j3 tube and multiple compatible tubes supports experimentation and DIY applications in audio and electronics projects. 23 use scenarios DIY audio preamp or small tube amplifier project Use the device with a DC supply in the 1216V range (prefer 12V  1.5A). Start with the included 6j3 tube (disassembled) and experiment by swapping in one of the compatible tubes such as 6J1, 6J2, 6J4, 6J5, 6AK5, or EF93 to explore tonal differences and response. Tube experimentation and learning Use the wide compatibility list to compare different tube types in the same circuit. Swap tubes to observe changes in gain, headroom, and frequency response, using a stable 1216V power source. Equipment upgrade or workflow or upgrade tubes in a compatible tubebased module or device by selecting from 6J1, 6J2, 6J3, 6J4, 6J5, 6A2, 6K4, 6K5, 6AK5, 6AU6, 6BA6, 6BD6 EF93  6K7 GE5654, etc. Maintain operation with the specified power requirements and the indicated power socket. Notes The 6j3 tube is supplied/disassembled, so some assembly is required. The listed tube types are compatibility references; when selecting tubes, ensure they match the device's operating characteristics and pins. This description preserves the original product's brandlike specifications and functionality while presenting clear, concise, and customerfriendly information.