Dilshan R Jayakody’s Web Log

This is a single chip dynamic microphone preamplifier which is design to drive using commonly available 12V single rail power supplies. Preamplifier in this article is built around popular NE5532 dual low noise operational amplifier IC and this preamplifier is specifically constructed to drive professional 600Ω dynamic microphones. Internal view of a dynamic microphone preamplifier prototype. This preamplifier consists of two amplifier stages and the initial amplifier is designed to get 36dB gain and final preamplifier is used to get 16dB of gain. Preamplifier gain controller is placed in between those two amplifiers and this separation allows reducing clipping in the output waveform. In prototyping stages, we test this preamplifier with few 600Ω dynamic microphones with a TDA2050 power amplifier . According to our observations, this unit produces excellent output with all of these microphones. To get professional results to use this preamplifier with 12V battery or with regu...

Audio Signal Generator (or AF Signal Generator) is often used in RF and AF base designing and experiments. In this article we introduce less complex AF signal generator based on commonly available electronic components. The heart of this AF signal generator is Intersil ICL8038 precision waveform generator/voltage controlled oscillator IC. ICL8038 is a function generator capable of producing sine, square and sawtooth waveforms at same time. In this project we combine ICL8038 with inverting and non-inverting amplifiers to get above mentioned 3 waveforms with 0° and 180° phase differences at the same time. Those inverting and non-inverting outputs help to use this AF signal generator with balanced audio systems. Final version of AF signal generator. The given schematic and PCB design of this AF signal generator contains ICL8038 waveform generator, inverting and non-inverting amplifier stage, output buffer and 12V regulated power supply. All the above mentioned modules are integrat...