KA2284Audio
5-LED VU meter
5-LED VU meter built with the KA2284, a dedicated IC that rectifies an audio signal and distributes it across a bargraph of three green LEDs, one yellow and one red.
Audio
INA1650Audio
Balanced line driver for XLR output
Balanced line driver for XLR output based on the Texas Instruments INA1650, with laser-trimmed matched internal resistors, integrated EMI/RFI filters and dual ±18 V supply.
OPA1678Audio
Phantom-powered piezoelectric microphone preamplifier
Differential preamplifier for a piezoelectric microphone powered by phantom power, with ESD protection and Zener clamping, using both channels of the OPA1678 as mirror branches.
LM386Audio
Mono audio amplifier
How to build a low-power mono audio amplifier with the LM386, a gain capacitor and a coupling capacitor to drive a speaker directly from a 4 to 12 V supply.