Simple, high-quality condenser microphone DIY for under $100

You need a good quality microphone, but all the available options are either a bit pricey or don't perform very well, so take this into consideration and decide to make your own. There is almost no self-noise due to the simplicity of the circuit and the performance of the op amp selected, ample dynamic range, and lack of signal distortion/"coloration". #### Component Selection Considerations 1. You can use almost any FET input op amp, **but** you must pay close attention to quiescent current. This circuit uses a fairly high impedance power path, and phantom power standards can't supply much current in the first place. The total power consumption of the two op amps should not exceed ~7-8mA (3.5-4mA each). 2. Hex inverters do the same in terms of power consumption, but anything else will do. You can replace this part with any 40106 clone with similar functionality. 3. Be careful when purchasing high voltage capacitors as specified - this is important! Ceramic capacitors lose capacitance at higher voltages, so X7R class capacitors rated at 100V or higher are preferred (this won't explicitly solve the derating issue, but it will help). All values ​​are readily available in 0805 size, so this is not an issue. 4. If budget allows, choose NP0/C0G ceramic capacitors. They will improve performance slightly, but not a lot. (This will solve the derating issue, but at a high cost)