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. Item Type: Vacuum Tube Preamplifier Material: Aluminum alloy Model: T11 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) Support 2 Model Tubes: (Default package 6N2) 1 x Vacuum Tube Preamplifier 3 x Metal Tube Cover 1 x 6Z4 Tube 3 x 6N2 Tube 4 x Acrylic Tube Cover 1 x Charging Cable 1 x Connection Cable 15 x Screw 1 x Instruction