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300W RMS Power Amplifier - 2SC3858 and 2SA1494 Transistors + PCB

Fig 1 - PCB 300W RMS Power Amplifier


This is a 300W RMS Power Amplifier using a complementary power transistors 2SC3858 and 2SA1494, this circuit amplifier isn't so simple to building, it will be necessary to have at least a little experience in electronics, to set up this circuit, its complexity is moderate, but, if you haven't skills in electronics circuits, we advise you not to do it, however, if you really want to do it, call someone with experience, to help you.

This amplifier has an excellent audio quality, and use four output power transistors, it reaches a sound power of 300W RMS under load of 4 ohms, powered with a symmetric power supply. You can check the schematic diagram in Figure 2 below.

Fig. 2 - 300W RMS Power Amplifier

Power Supply

The power supply consists of a symmetrical transformer 45V - 0 - 45V center tape, 6 Amperes current supply, can be used. After rectified, we will have approximately 63Vcc at the output of the symmetrical power supply .

Components list

Q1, Q2, Q3, Q5 ......... C1815 NPN Transistor
Q4 .............................. A1015 PNP Transistor 
Q7 .............................. TIP 42C PNP Transistor
Q8, Q9 ....................... 2SC3858 NPN Power Transistor
Q10, Q11 ................... 2SA1494 PNP Power Transistor
Q6 .............................. TIP41C NPN Transistor

D1 to D7 .................... 1N4148 diode, or equivalent diode 1N4001 

C1, C4 ......................... 2.2uF - 25V Electrolytic Capacitor   
C2 ............................... 220pF Polyester / Ceramic Capacitor 
C8 ............................... 100nF Polyester / Ceramic Capacitor 

R2, R10 ....................... 47k ohms resistor (yellow, violet, orange, gold)
R3, R5 ......................... 2.2k ohms resistor (red, red, red, gold)
R4 ................................ 270 ohms resistor (red, violet, black, gold)
R6, R7 ......................... 51K ohms - 1/2W resistor (green, brown, orange, gold)
R8, R9, ........................ 100 ohms resistor (brown, brown, black, gold)
R11 .............................. 470 ohms resistor (yellow, violet, brown, gold)
R12 .............................. 390 ohms resistor (orange, white, brown, gold)
R13, R14 ..................... 100 ohms - 2W resistor (brown, brown, black, gold)
R17, R18 ...................... 6R8 ohms - 1W resistor (blue, gray, gold, gold)
R15, R16, R19, R20 .... 100 ohms - 1W resistor (brown, brown, black, gold)
R21, R22, R23, R24 .... 0.33 ohms - 5W resistor (orange, orange, gold, gold)
R25 .............................. 22 ohms resistor (red, red, black gold)
R26 .............................. 10 ohms - 1W resistor - (brown, black, black. gold)

P1, P2 ........................... 2 Pin - PCB Terminal Blocks - EK500V-XXP 20A - or equivalent
P3 ................................. 3 Pin - PCB Terminal Blocks - EK500V-XXP 20A - or equivalent
Others ........................... Loudspeaker, Wires, Solders and Etc.

For those who want to download materials such as the schematic diagram in PDF, PCB Layout,  GERBER and JPG, we are providing a direct link to download all the material.

Direct link to download

Click in the link below to download the Files: PCB Layout, PDF, GERBER, JPG

If you have any questions, suggestions or corrections, please leave them in the comments and we will answer them soon.

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My Best Regards!!!

Post a Comment

2 Comments

  1. Hi everyone,
    I am mounting the PCB as the components are written, and at the output of the SP I get a voltage of about 30vdc and being, so I think the diagram is not correct,
    I have already written in other posts some errors, that I had the PCB (Q1 C1815 transient), could someone give me a clue where the problem is?
    there I put Photos
    Beste Regards

    ReplyDelete
    Replies
    1. Hi RAFFI!
      This Circuit had a pin inversion error on two transistors C1815 and A1015.
      The software library that we used to make the PCB, had the pinning of these transistors inverted. We have already fixed and are already updated on our website.
      We apologize for the unfortunate event.
      And thanks for sharing your experience with us.

      My regards

      Delete