Features:
Vacuum tube preamp with Bluetooth; Convenient to improve your sound quality

Audio signal input can be computer CD phone and lossless player

Three kinds of audio input: RCA; 3.5mm stereo input; Bluetooth

Easily switching between different sound sources with its audio input selection

Audio output can be connected to digital amplifiers and active multimedia audio devices

Treble & bass adjustment; Sound is warm and broad; No background noise

Gold-plated for input and output terminals; 6J1 valve tube; Mini size suitable for desktop

Troubleshooting:
Please note that this product is a preamplifier. It is not an amplifier and needs to be connected with an amplifier or active audio devices. Also it is not a phono preamp and cant work with a turntable.

For noise issue:

There is a large probability that the low-quality audio cable causes the static noise.

Please make sure the sound source is fine since tube amplifiers will amplify all sound including the noise.

Please check whether the tubes are plugged well on the tube sockets or not.

Devices like routers mobile phones will also interfere in the audio signal and may cause static noise.

If your problem cant be solved please feel free to contact us. We will be very glad to help you and try our best to make you satisfied.

Specifications:
Audio input: 1 set of RCA input; 1 * 3.5mm stereo input; 1 * Bluetooth input
Audio output: 1 set of RCA output
Dimensions: 16*11.5*7 cm (including tube height)
Power supply: universal 12V DC

Packing List:
1 * PreAmp
1 * Power supply
3 * 6J1 tube
1 * Bluetooth antenna