<br>Regarding the hum (ground noise), the vacuum tube amplifier has very high requirements for the power supply. <br>And it is very susceptible to interference from other electrical appliances around, especially WiFi routers. <br>If you have humming or other noises on both channels, you can try to turn off or remove the electrical appliances near the tube Amplifer that may affect it. <br><b> Features: </b> <br>If you listen the BoyuuRange A50 MKIII Amplifier, you will know 300B is good at bass too. <br>Imported 0.35 core output amplifier audio dedicated core, core stack thickness 86-50, A20 flux of 13,000. <br>Output transformer potting techniques, ensure that the output of the amplifier stability and reliability <br>Double chassis design. U-shaped steel chassis thickness up to 2.4 mm thick <br>Output amplifier with a new imported 0.35 core manufacturing, high-purity copper wire package enameled <br>Imported 0.35 thick core manufacturing power amplifiers <br>Output amplifier with high-grade stretch amplifier housing cover. <br>Power Transformers: new imported 0.35, stack thickness 60MM (114-60). <br>Output amplifier core: core 0.35 new imported thick high silicon (86-50). <br>Japanese production of ALPS potentiometer. <br>Chassis: imported mirror stainless steel chassis. <br>Aluminum panel: high-grade aluminum CNC machining, anodic surface treatment. <br> <br> <br>Specification: <br>AC110V- AC120V(60Hz/50Hz) <br>Voltage amplification and promotion tubes: 6N8P (6SN7)x 2 <br>Power output tube: 300Bx2 (brand PSVANE) <br>Rectifier: 5Z3PATx1 <br>Output power: 7.6W x 2 (Class A) (no feedback technology) <br>Frequency response: 30Hz-42KHz <br>Output impedance: 4ohms, 8ohms <br>Total harmonic distortion: 1% (1kHz) <br>Input sensitivity: 750MV <br>Input impedance: 100Kohms (3 groups of input jacks) <br>Volume: 375 W x 290 D x 180 H mm <br>Packing volume: 500 W x 450 D x 290 H mm <br>Signal to noise ratio: 89DB <br>Net weight: 18 kg <br>Gross weight: 21 kg