2 Pcs/lot YJ00170-E405 Amplifier Board Empty Board

• The resistance selects a five-ring metal resistor, and the main loop adopts a five-ring metal film resistor with an accuracy of ±1%.
• The biggest feature of this board is the use of the current advanced C1237 BTL speaker protection circuit, effectively eliminating the on-off and shutdown shock sound and DC output protection functions, making your speaker safer.

• Basic parameters:

  1. Power supply: DC+- (35V-55V) Recommended +-45V and AC12V

  2. Power: 300 watts (total harmonic distortion THD+N<0.1%), DC+-45V, 4 ohms

  3. Class A 90W, measured under 4 ohm load

  4. Horn impedance: 4-8 ohms.

  5. PCB size: 59*236MM.

  6. First adjust the differential input stage current to 2MA: adjust the VR1 (500R) adjustable resistance so that the voltage at both points of C and D is 1.5-2V (that is, the voltage across the R9(1K) resistor); At this point, the input differential current is 1.5-2MA, which is the best sound quality

  7. The quiescent current of the large tube is 100MA: the adjustable resistor VR2 (1K) is adjusted so that the voltage of A and B is 22MV, and the quiescent current I = 22MV/0.22R resistor is 100MA; If the customer's heatsink is large enough, it can increase the quiescent current, generally 100MA-300MA sound effect is the best.