Feature:1. Sound adjustment: support high or medium or bass EQ adjustment, enhance and15dB and attenuation -15dB, support left and right channel balance adjustment, suitable for tone adjustment.2. Three sets of stereo mixed input :3.5mmand6.5mmandRCA.3. Provides three sets of stereo output simultaneously:RCAandRCAand3.5mm.4. Independent Toner Audio Control: With independent audio source channel high or middle or bass control. Attenuations -15dB and and15dB gain, the sound adjustment design allows you to adjust the audio independently and control the output volume independently.5. Simple installation: input and output plug and play easy installation, enjoy music instantly.6. USB 5V power supply, suitable for outdoor mobile power use, with wider application range.7. Compact and desktop design, and can be compatible with any devices.Specification:Features:Sound adjustment: support high or medium or bass EQ adjustment, enhance and15dB and attenuation -15dB, support left and right channel balance adjustment, suitable for tone adjustment. Three sets of stereo mixed input :3.5mmand6.5mmandRCA.Provides three sets of stereo output simultaneously:RCAandRCAand3.5mm.Independent Toner Audio Control: With independent audio source channel high or middle or bass control. Attenuations -15dB and and15dB gain, the sound adjustment design allows you to adjust the audio independently and control the output volume independently.Simple installation: input and output plug and play easy installation, enjoy music instantly.USB 5V power supply, suitable for outdoor mobile power use, with wider application range.Compact and desktop design, and can be compatible with any devices.Specifications:Material: MetalInput channel: 3-way stereo input 3.5mmand6.5mmandRCA interfaceOutput channel :3.5mm or RCA interfaceInput impedance :100K OhmOutput gain: high, medium and low -15dB and and15dBFrequency response: 20Hz-20KHzSignal to noise ratio: more than 107dBTotal Harmonic Distortion: less than 0.08 percent Intermodulation distortion: less than 0.01 percent Charging Connection: USB 5VItem Size: 130 x 77 x 38mm or 5.11 x 3.03 x 1.49inItem Weight: 380g or 13.4ozPackage Weight: 530g or 18.69ozPackage Size: 20 x 18.5 x 5.5cm or 7.87 x 7.28 x 2.16inPacking List:1 x Stereo Preamplifier1 x USB power cordPackage List:1 x Stereo Preamplifier1 x USB power cord