50W功放电路(50WattAmplifier)

50W功放电路 (50Watt Amplifier)
  
  This is a handy, easy to build general purpose 50 watt amp. The amp has an input for a radio, TV, stereo or other line level device. It also has a phono input for a record player, guitar, microphone or other un-amplified source. With the addition of a low pass filter at the input, it makes a great amp for a small subwoofer.
  Parts
  Part
   Total Qty. Description
   
  R1 1 200 Ohm 1/4 W Resistor
  R2 1 200K 1/4 W Resistor
  R3 1 30K 1/4 W Resistor
  R5 1 1K 1/4 W Resistor
  R6 1 5K 1/4 W Resistor
  R7,R10 2 1 Meg (5%) 1/2 W Resistor
  R8,R9 2 0.4 Ohm 5 W Resistor
  R11 1 10K Pot
  R12,R13 2 51K 1/4 W Resistor
  R14 1 47K 1/4 W Resistor
  C1 1 100uF 35V Electrolytic Capacitor
  C2 1 0.011uF Capacitor
  C3 1 3750pF Capacitor
  C4,C6 2 1000pF Capacitor
  C5,C7,C8 3 0.001uF Capacitor
  C9 1 50pF Capacitor
  C10 1 0.3uF Capacitor
  C11,C12 2 10,000uF 50V Electrolytic Capacitor
  U1,U2 2 741 Op Amp
  U3 1 ICL8063 Audio Amp Transister Driver thingy
  Q1 1 2N3055 NPN Power Transistor
  Q2 1 2N3791 PNP Power Transistor
  Notes
  1. I know I skipped R4. That is not a problem :-)
  2. Distortion is less than 0.1% up to 100HZ and increases to about 1% at 20kHz.
  3. I haven't been able to find anyone who sells a suitable T1. You can always use two 24V 5A units in series. If you are building two amps (for stereo), then I would suggest using an old microwave transformer and rewinding it.
  4. Q1 and Q2 will require heatsinks.
  5. You may have trouble finding U3 because it is discontinued. Please don't email me about sources...I can't find it either. A possible source was sent in by JBWilliams: