Electret Mic Stereo Preamplifier

I was looking for a simple per-amplifier circuit. Found one at http://www.minidisc.org/mic_preamp/Simple%20Stereo%20Electret%20Mic%20Preamp.htm. I made minor modifications and here is my version. Gain is set by R7 and R8 in left channel and R9 and R10 in left channel. In each channel gain will be 1+ (33K/3.3K) = 11. Replacing 3.3K resistors with 1.5K resistor will […]

Thermocouple Amplifier with OP07C Op-Amp

Recently I created a soldering station based on Arduino Pro mini. It involves reading temperature data from thermocouple within soldering iron. Thermocouple produce a very little voltage, around up to 30 Milli volts for soldering irons. So, soldering station uses an op-amp based circuit to amplify those small signals from thermocouple to signal high enough […]