1. 6J1 fever gall bladder before the board is imitation machine music fax X-10D circuit principle design, to be a reasonable optimization, more stable than the original machine performance, the tube to play increased by 10 percent. 2. This machine uses a single 12V AC input, do not have to worry about looking for high voltage power supply The board comes with a boost you enjoy the low power supply to enjoy the charm of high-voltage tube. 3. Coupling capacitor using Taiwan electrode without charge MET series, high-frequency low-resistance electrolytic capacitors, 1% precision metal film resistors, J-class regulations tube 6J1. Power works: A power supply, tube filament began to heat, then boost from the zero voltage began to boost, and other tube filament hot, the boost is just boost finished, so this is the same with the gall bladder rectifier, 8 470UF the capacitor filter is very clean, supply system not have the exchange of sound. The filament is DC 12V power supply, the need for two tube filament is in series, the use of DC filament is also to reduce noise. 6J1 Electronic Tube Preamplifier Board DIY Kits Preamp Amplifier Module Bile Amp Effect Parts Model: 6j1 Tube (replaceable models 6AK5,6AU6,5654, etc.) Channel type: 2.0 / stereo Power input: AC AC12V 0.8A /5.5 * 2.5 plug Weight: . 70g Knob function: power switch / volume adjustment It's DIY kits, needs to finish by yourself. Color: As Shown Material: Plastic+Metal Package Contents: 1 set * preamplifier DIY parts Only the above package content, other products are not included. Note: Light reflection 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.