Description: Attention: It is the front stage and the front stage. The sound can only be heard when it is pushed by the rear stage. It cannot be directly connected to the horn DIY Kit,Need buyer to weld 1. SIZE: 77 MM * 75 MM * 52 MM 2. Power input: AC 12 V 1 A 5.5 * 2.5 PLUG 3. Channel: 2.0 / Stereo 4. Potentiometer Function: Volume + Power Switch setting Specification: FE-6J1-2 tube fever plate pre-amp is the circuit schematic imitation design team Music fax X-10D, to be rational optimization, more stable performance than the original machine, 10% tube set increase. This board uses a single 12 V AC input battery, the processing circuit provides 6J1 tube required positive and negative voltage and voltage supply filament voltage. Energy works: an open tube feeding the filament heating is started, when the impulse from zero-tension start to increase the hot filament tube, etc., also happens to boost boost finish, so this is the same with the 8 * 470 UF capacitor very clean filter, good power supply system will not have a buzzing, the filament is 12 V DC power supply, needs two tube is connected in series with a DC filament filament too in order Reduce noise. Package included: 1Set