This small module is used to cut the entire audio spectrum below 100 Hz.
When recording audio, you realize that a tone control isn't everything. You can try to lower unwanted sounds with a tone control, but it's a whole frequency range that disappears. While in the 70s and 80s, the Low Cut filter was only found in well-made mixers, it wasn't until the 90s that it appeared in Folio-style mixers from Soundcraft, Mackie, and many others. Today, it's found in all podcasting equipment and sound editing software. Personally, I implemented this circuit in a mixer that didn't have one and had enough space to accommodate a small PCB and an inverter. The solution for inserting this module at the mic preamp output without cutting a track was to remove the bridging capacitor to ensure continuity. The basic schematic is a second-order, low-cut Butterworth filter with a slope of 12 dB/octave.
Here's the principle: The schematic has been adapted so that everything is on the PCB with the Bypass/Filter inverter:
It will be easy to modify the frequency using the attached formula.
Discussione (1 nota(e))