Simple non linear low pass filter
This is a simple simple non linearlow pass frequency filter circuit on passive model. We use passive components without transistors and any ICs. So is easy circuit. and It is small size and easy to made for do not used the external power supply, but refuse a lot of noise ripples and need to a input voltage is stable. and a lower amplitude. The circuit will work best, when the signal level is importantly higher than the constant ripple level.And The circuit has specifically related to two peak-detecting sample-and-hold circuits in tandem with a voltage average. There are parts in …
Simple  compressor with 1N914
This simple compressor circuit is suitable for use in a recorder tape from the speaker terminals of the receiver.This input can be changed from 200 mV to 6V. The output will remain at close to 5 mV. An attack time of the circuit for about 3 ms and release time of approximately 100 milliseconds, for the diodes in the circuit should be the type of high back resistance, such as number 1N914.