Feature: 1. Better Sound Quality: Compared to the T10, the T11 preamp has lower background noise at normal volume, and it sounds better. 2. Active RIAA Circuits: The amplifier uses a traditional active RIAA balanced phono circuit. The GND switch on the rear panel is set to ground by default. If there is a lot of noise, please try to set it to disconnect from the ground. 3. Aluminum Alloy Case: This preamp features an enhanced manufacturing process and features a aluminum alloy case for a more elegant and sophisticated look. 4. Various Replaceable Tubes: Supporting 6N2 or 12AX7 tubes, which offers many replaceable tubes for you, such as 6H2,6H2n (For 6N2 type) and 12AX7B,6N4(9PIN),ECC83,5751 (For 12AX7 type). 5. Small Size: This preamplifier is small enough to take on the go, and we've included 3PCS metal covers and 4PCS acrylic covers for you to choose from. Specification: Item Type: Vacuum Tube Preamplifier Material: Aluminum alloy Model: T11 Output Voltage: 2.0V Gain: =48dBv Input RIAA: ??5mV Total Harmonic Distortion: ??0.5% Frequency Response: Standard Characters Signal to Noise Ratio: ??65dB(A) 1KHz (Input: 10mV output: 0.7V) Power Supply: AC110/220V 60Hz/50Hz Support 2 Model Tubes: (Default package 6N2). Package List: 1 x Vacuum Tube Preamplifier3 x Metal Tube Cover1 x 6Z4 Tube3 x 6N2 Tube4 x Acrylic Tube Cover1 x Charging Cable1 x Connection Cable15 x Screw1 x Instruction Note: For MM phono turntables only. Make sure your turntable is equipped with a PHONO signal output and not a LINE output