873
FREE
circuits!
FREE
circuits!
How to build 18watt Audio Amplifier
August 6, 2010 - category: Audio amplifierCircuit Diagram:
Circuit Diagram:
Amplifier parts:
- P1 = 22K
- R1 = 1K
- R2 = 4K7
- R3 = 100R
- R4 = 4K7
- R5 = 82K
- R6 = 10R-1/2W
- R7 = 22R
- R8 = 1K-1/2W (optional)
- C1 = 470nF-63V
- C2 = 100µF-3V Tantalum bead Capacitors
- C3 = 470µF-25V
- C4 = 470µF-25V
- C5 = 100µF-3V Tantalum bead Capacitors
- C6 = 100nF-63V
- D1 = 1N4148
- IC1 = TLE2141C
- Q1 = BC182
- Q2 = BC212 50V 100mA PNP Transistor
- Q3 = TIP42A
- Q4 = TIP41A
- J1 = RCA audio input socket
Power supply parts:
- R9 = 2K2
- C7 = 4700µF 25V
- C8 = 4700µF 25V
- D2 = 100V 4A Diode bridge
- D3 = 5mm. Red LED
- T1 = 30VCT, 50VA Mains transformer
- PL1 = Male Mains plug
- SW1 = SPST Mains switch
Notes:
- Can be directly connected to CD players, tuners and tape recorders.
- Do not exceed 23 + 23V supply.
- Q3 and Q4 must be mounted on heatsink.
- D1 must be in thermal contact with Q1.
- Quiescent current (best measured with an Avo-meter in series with Q3 Emitter) is not critical.
- Adjust R3 to read a current between 20 to 30 mA with no input signal.
- To facilitate quiescent current setting add R8 (optional).
- A correct grounding is very important to eliminate hum and ground loops. Connect to the same point the ground sides of J1, P1, C2, C3 & C4. Connect C6 to the output ground.
- Then connect separately the input and output grounds to the power supply ground.
circuit from http://www.extremecircuits.net/2009/07/18watt-audio-amplifier.html
This category