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Same version as the previous, but optimised for class A operation, providing excellent THD ratings and good overall efficiency.
- Input sensitivity - 3.3Vmax for full output. Will require the circuit i posted - Ultra low THD Preamp.
- Frequency response - 1Hz - 35Khz@-3dB
- Output Power - 200Wrms/4ohm
- Power Consumption - 506W
- Efficiency - 40%
- Ripple rejection - good at -48dB (2mV residual 100Hz hum)
- THD+N - 0.0025% @ 200Wrms/4ohm
A few tips:
- Use no less than 10mF for the power supply filtering. 22mF per rail is best. The rectifier should be rated no less than 15A. The more the better.
- Place the mode determining transistor ( the middle one just below the red line) close to the heatsinks, to compensate for thermal drift, bound to occur due to nonsymmetricity of the parameters of the power transistors and the non - perfection of the differential amplifier.
- Place a few 100nF capacitors along the supply rails to compensate for high frequency ringing, and to ensure high frequency stability. Also place 1-2 100uF caps close to the power transistors.
- This has no output protection circuitry, so be careful not to short the output. Large amounts of current will be drawn and many components may fail. I suggest adding 2x10A fuses at the input of the supply rails to ensure such a spike will not damage any components. Remember, if you fail to limit the current draw, you'll be left at the mercy of your power supply, which may also fail. Be cautious.
- The power resistors (220mohm) should be rated at least 1W. 2W wirewound is best
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