Specifications: Musical Fidelity is a product launched in the mid-1990s. Excellent sound effects, cute and unique appearance, which caused a lot of excitement in the market. Its function and advantages are: The connection between VCD, CD, DVD, CD-ROM and other digital audio and amplifier. Can greatly reduce the "digital taste" and "transistor sound", so that the whole sound system has a sweet, natural "bile taste". Uses a convenient AC 12V 500mA power supply. You don't have to worry about looking for a high voltage power supply. The board comes with a boost. Allows you to enjoy the charm of a high pressure tube under low supply. The board contains two 6J1 tubes, just connect the transformer and it can work. 1. Voltage: AC 12V 500mA 2. Dimensions: 170mm x 60mm, height 28mm 3. You need to add a transformer to make the board work. 4. It is a soldering kit. Package includes: 1*6J1 tube preamp preamplifier kit, assembled board, audio music fidelity