Features: Low noise integrated circuits and components convert phonograph signals to line level signals to eliminate low frequency noise and ensure clear sound quality. Protect your turntable with a grounded column design. Three switchable gain modes: 39, 42, 45dB. Adjustable gain levels give you customizable control and superior compatibility. Entry level high end sound and top of line circuitry for unmatch low cost. Tubular preamplifier: It is also a tubular preamplifier with a 3.5mm input. components. The is smooth. Apply vacuum tube type: 6J2/6K4/6J1/6J4/GE5654/6AK5, etc. You can replace the vacuum tube to DIY your stereo system. Different tubes have different sounds. Specifications: Material: Aluminum Alloy Power adapter output: 12V/ 1.5A Product adapter input voltage range: 110V-240VAC Phono preamplifier Dinput voltage: 12VDC Output voltage level: 600Mv@3mV 1kHz SNR: 98dB Frequency response: Standard RIAA Type: 1/2/3/4 Note: It is only a preamplifier, not an amplifier, and cannot be connected directly to a passive speaker. If you need to connect it to a passive speaker, you'll need to connect it to an amp, and then connect the amp to your passive speaker. Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1x Preamplifier 2x Vacuum Tube 1x DC12V Power Adapter 1x Manual 1x Cable