1Pair E405 300W amplifier board reference accuphase circuit power amplifier board A1943/C5200 2SA1930/2SC5171. We only sell the products, do not provide schematics. Please note that each part must use a. You can not use the same power supply for two boards, they will be burned, thank you. Power supply: DC + – (35V-55V) recommended + -45V and AC12V. Power: 300W total harmonic distortion THD + N. Class A 90W, measured under 4 ohm load. Speaker impedance: 4-8 ohms. PCB size: 59 236 MM. Set the input stage differential current to 2MA: Set the adjustable resistor VR1 (500R) so that the voltage between C and D is 1.5-2 V that is, the voltage at resistor R9 (1K); The input differential current is 1.5 to 2 mA. This value is the best sound quality. The quiescent current of the large tube is 100MA: adjust the adjustable resistor VR2 (1K) so that the voltage of the two points A and B is 22MV. At this time, the quiescent current I = 22MV / 0.22R is a resistance of 100 mA; If the customer’s heat sink is large enough, it can increase the quiescent current. Usually, the sound effect 100MA-300MA is the best. A pair of cards with balanced left and right inputs. Use the original Toshiba A1943 / C5200 and 2SA1930 / 2SC5171. The interstage coupling capacitor adopts WIMA top capacitor 1UF, and the main circuit of electrolytic capacitor signal adopts imported Panasonic brand name to ensure strong and continuous current support. The resistor consists of a metal ring with five rings. The main circuit adopts five-ring metal film resistor with ± 1% accuracy to ensure good signal-to-noise ratio. PCB adopts 1.6mm thick double-sided sheet, 2.0 ounces copper thickness and full process of spray tin to ensure good performance in large and small currents. The biggest feature of this board is the use of the latest advanced C1237 BTL speaker protection circuit, which effectively eliminates the impact and DC output protection of opening and shutting down, making your speaker safer. The layout of the whole PCB is quite strict and reasonable, and the PCB track uses grounding method. The power amplifier board works stably and reliably, and the output power is large; The sound is beautiful and round, and the sound field is wide. The three-dimensional sense is strong, the low frequency is solid and sound, the signal-to-noise ratio is very good, the dynamic range is large, the details are clear, the transient response is excellent, and all kinds of music are possible played comfortably. It has a very good performance in the family playback environment. 1 Pair E405 Tube Power Amplifier Board 300W AMP A1943 / C5200 2SA1930 / 2SC5171. Your Feedback is really important to us, please take a few seconds to leave great feedback if you are satisfied with our product or service, thank you so much!
