6J5 Vacuum Tube Amplifier Preamplifier BT Preamp AMP with Volumes Treble Bass Tone Adjustment Function for Home Sound Theater This amplifier adopts 6J5 electronic tube and fine-quality NE5532, and BT4.2 version do not support APTX function. The main filter capacitor adopts 470UF/25V, and the coupling capacitor adopts 1UF capacitor. The PCB adopts 1.6mm thickness double-sided sheet, 2.0ounce copper thickness, and the whole process of tin-spraying ensures the fine passing performance of the current. Features: Using 6J5 electronic tube and fine-quality NE5532, and BT4.2 version do not support APTX function. The main filter capacitor adopts 470UF/25V, and the coupling capacitor adopts 1UF capacitor. The resistor uses a high precise chip resistor, and first-class printed circuit board quality. The printed circuit board adopts 1.6mm thickness double-sided sheet, 2.0ounce copper thickness, and the whole process of tin-spraying ensures the fine passing performance of the current. The layout of board is reasonable, beautiful, and with small current noise. The input and output interface are made of gold-plated lotus pedestal, which is long lasting and beautiful. Three knobs design improves everything detail, transparency, immediacy, richness, you can get both powerful or sweet sound easily. Specifications: Name: Preamp Material: printed circuit board Color: black, silver (optional) Power supplys: DC12V Item size: 137 * 104 * 41mm / 5.39 * 4.09 * 1.61in Package size: 250 * 200 * 70mm / 9.84 * 7.87 * 2.76in Package weight: 500g / 1.10lb Packing List: 1 * Preamp