The input end is designed with a balanced circuit, supporting both single-ended and balanced input. Single-ended input uses a two-core mono plug, while balanced input uses a three-core two-channel plug. Balanced connections are suitable for long-distance transmission, and single-ended connections are ideal for short-distance transmission. If you are unfamiliar with these terms, you can use the device normally without adjustment. The output port is unbalanced single-ended and compatible with a 6.5mm two-pin plug. Note: 6.5mm is also referred to as 6.35mm, and internationally known as 1/4 inch. Dual-channel amplification with gain adjustment (0-20dB). Both channels can be used independently or simultaneously without interference. Working frequency: 20Hz-20kHz Input impedance: 10k (single-ended), 20k (balanced) Output impedance: 200 Operating voltage: DC 5V-12V Static power consumption: 0.3W Operating current: 73mA at 5V, 30mA at 12V For 5V power supply, a power bank or high-quality charger can be used. Low-quality chargers may affect performance. Dimensions: approximately 10.8 x 4.2 x 2.7cm Material: plastic and metal Color: black Package Contents: 1 x amplifier 1 x charging cable Only the items listed above are included; other accessories are not included. Note: Lighting and display differences may cause slight variations in color between the image and the actual item. Measurement allows an error of +/- 1-3cm.