30 watt DIY audio power amplifier

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30 watt DIY audio power amplifier
30 watt DIY audio power amplifier

In this article, we will tell you what components are needed to build your own 30-watt audio amplifier with your own hands at home. Printed circuit board in LAY format is attached. It happens that there is a need for amplifiers with a large nominal power, and the sound quality to be excellent. Naturally, buying such equipment is a little expensive, then the thought comes, "Wouldn't you like to assemble such an amplifier yourself at home?" Here we offer a simple 30-watt sound amplifier circuit, which can please with both power and sound quality.

The proposed scheme is not new, proven. A pair of transistors (Darlington) in TOP3 package should be installed on the cooling radiator. Between them, in turn, you should put mica for insulation, and in order to have good heat transfer, you need not to regret the thermal paste and apply (KPT-8).

In this circuit, a TR resistor is installed, it is needed to set the quiescent current. To adjust this resistor correctly, you need to: fasten the clamps of the multimeter to the ends of the resistors R20 (or R21) and measure the voltage (the maximum power on the multimeter should be 200 mV), then adjust the received power on the TR resistor to the 12 mV mark.

This voltage drop can be equated to a DC current of 30 mA. Let the sound amplifier stay in this constant state for about 15 minutes without an input signal, and then check the readings again.

Sound amplifier circuit power at 30 watts

List of components for building a 30 Watt audio amplifier:


  • R1 = 1 kΩ
  • R2 = 47 kΩ
  • R3 = 1.5 kΩ
  • R4-5 = 10 kΩ
  • R6 = 5.6 kΩ
  • R7 = 10 Ohm
  • R8 = 47 kOhm
  • R9 = 560 Ohm
  • R10-11 = 8.2 kΩ
  • R12-15 = 120 Ohm
  • R13 = 680 Ohm
  • R14 = 330 Ohm
  • R16-17 = 270 Ohm
  • R18 = 22 Ohm 1W
  • R19 = NC
  • R20-21 = 0.39 Ohm 4W

All resistors are 0.250W 1% accuracy except as specified. Zener Diodes:

D1 = 9.1V 0.4W


D2-3 = 1N4148


  • VT 1-2 (Q1-2) = BC550C
  • VT3 (Q3) = MPSA56
  • VT 4 (Q4) = BC547B
  • VT 5 (Q5) = BC212
  • VT 6 (Q6) = BC183
  • VT 7-8 (Q7-8) = MPSAO6
  • VT 9 (Q9) = TIP141
  • VT 10 (Q10) = TIP146


  • C1 = 100V 470nF MKT (polystyrene)
  • C2 = 100V 1nF MKT (polystyrene)
  • C3 = 68pF (ceramic)
  • C4-8 = 22nF 100V MKT (polystyrene)
  • C5-6-7 = 100V 100nF MKT (polystyrene)
  • C9 = 25V 47uF
  • C10-11 = 220uF 63V


F1-2 = 1.6A

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