Personally, it was one of my first steps into modular synthesizers. Nice sounds, easy approach. Peter Kirn is perfectly picturing this amazing compromise here!
Synths: they’re fun to tweak and play. Modulars: they’re fun to patch. Arduinos: they’re fun to hack. Small things: they’re fun to carry around.
But how to track patches? How to share sounds with friends? I was playing mainly with my son, and managed to print out a paper sketch depicting all the different pinout of the synth. I wasn’t satisfied with that, I needed more!
AN6877 is linear AF level meter IC produced by Panasonic and it is commonly found on many audio equipment. This chip is no longer manufactured by Panasonic and finding replacement chip for AN6877 is also quiet difficult.
The circuit described in this article is design to replace AN6877 base LED drivers and it is based on commonly available components. This replacement LED driver is design using 10, MMBT3904/2N3904 transistors and it can easily modify to get necessary number of outputs.
This project is to act as a central hub for switching between audio sources and listening devices. Multiple audio sources can include a phone, computer, TV, etc. The listening devices can include different sets of speakers, headphones, etc. This project aims at reducing the hassle of unplugging and reconfiguring the desired audio source and listening device to just a button press. There is also an integrated volume control knob on the audio mux to conveniently change the gain in the same location as the buttons.
This is single chip dynamic microphone preamplifier which is design to drive using commonly available 12V single rail power supplies. Preamplifier in this article is build around popular NE5532 dual low noise operational amplifier IC and this preamplifier is specifically constructed to drive professional 600Ω dynamic microphones.
This preamplifier consists with two amplifier stages and initial amplifier is design to get 36dB gain and final preamplifier is used to get 16dB of gain. Preamplifier gain controller is placed in between those two amplifiers and this separation allows reducing clipping in output waveform.
Phantom power supply is widely used in audio industry to power the active microphones over single audio cable. Most of the phantom power supplies deliver 48V DC over the balanced audio link and power supply unit described in this article is also based on same technique.
Phantom power supply in this article is based on TL783 high voltage regulator IC and 230V – 50V step down transformer. Like most of the phantom power supplies this power supply is also design to connect in between active microphone and audio mixer devices.
Audio output transformers are heavily used in vacuum tube and some (older) transistor base audio power amplifiers, but these days output transformer are quiet hard to find and expensive item. For homebrew projects the best option is to construct those transformers by ourselves and this script helps to calculate winding parameters for those transformers.
This “AF output transformer calculator” script is written using Python and it works with most of the commonly available Python interpreters.