<p>1. Using 6J5 tube, NE5532</p> <p>2. The capacitor uses the 470UF\/25V, and the coupling capacitor uses the capacitor 1UF.</p> <p>3. The resistor uses high-precision chip resistor to a good signal-to-noise ratio of the whole machine.</p> <p>4. PCB adopts 1.6mm thick double-sided sheet, 2.0 oz copper thickness, and tin-spraying process to good passing performance of large and small currents. First-class PCB quality.</p> <p>5. The input and output are made of gold-plated RCA lotus seat, which is durable and beautiful! The board layout is reasonable, beautiful, and the current is small.</p> <p>Basic parameters:</p> <p>Power supply: DC12V2A ( needs to be regulated by 12V, not higher than 12V)</p> <p>Machine size: about 129* 100* 35MM (without tube height)</p> <p>Panel function: switch treble adjustment bass adjustment total volume</p> <p>Note:</p> <p>1. This finished machine is a preamplifier, not an amplifier. It should be used with a post-amplifier or an active speaker. It is not allowed to directly connect passive speakers, speakers and earphones to the power amplifier; if it is not used, the car will be burnt if the voltage is unstable.</p> <p>2. The probability that the normal audio line or power supply is not good enough to cause the noise at the bottom noise is very high. It is recommended to use a good audio cable or power supply.</p> <p>3. Make sure that there is no problem with your source. The preamplifier itself has a preamplifier function. If itself is noisy, then the preamplifier will only amplify its noise. Please use a good source test.</p> <p>4. Check if the tube is plugged into the base. Please insert the tube and the base. Be sure to insert the tube in case of power failure.</p> <p>Note:</p> <p>Power supply is not included in the package. You need to buy 12V2A power supply by yourself.</p> <p>Material:Aluminum alloy</p> <p>colour:black</p> <p>Package Contents:</p> <p>1 * 6J5 Tube Preamplifier</p> <p>Only the above package content, other products are not included.</p> <p>Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +\/- 1-3cm.</p>