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Ultra High Gain Audio Amplifier:
This amplifier uses an Electret (capacitor) microphone element to produce tremendous gain. In fact, be certain that the gain is turned down before you don your ear phones and turning this unit on .. else you could cause ear damage. The circuit consists of a single BJT transistor used as a preamplifier with a gain of 105 that then drives the 386 power amp. A SPST switch will, when closed, allow full frequency amplification. When open, it will reduce the amplitude of frequencies below 150 Hz. The .001 uF capacitor shunts radio frequency signals to ground to reduce interference. To reduce the overall gain from outrageous down to just super loud, remove the capacitor between pins 1 and 8 on the integrated circuit. RGK
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