Signal generator

PICSynth analog synthesizer

PICSynth analog synthesizer is a real analog synthesizer to build using easy to get components, capable of a wide range of sounds. The two oscillators can be detuned for that classic synth sound.[more]

Posted in : PIC projects | Signal generator | Sound related projects

Poor Man’s DDS Board

This is among the simplest DDS-type boards which can possibly be built: Basically, it’s just an AVR RISC microcontroller connected to a DA converter.
8bit DA converter and fast R2R output buffer.
Up to 2MS/s (million samples per second).
Single 5V supply or USB-powered.
3 dedicated user-configurable IO ports (e.g. trigger input, sweep output, AD converter) and a diagnosis LED.
USB connection for waveform download via USB8Bit board.
8kb flash and 512 bytes SRAM, freely programmable 16MHz microcontroller.
USB-powered and externally powered operation.

Posted in : AVR projects | Signal generator

Voltage Controlled LFO

This is a nice LFO for all of your modulation needs. The frequency can be voltage controlled to add a new dimension to your sound palette. The pulse width of the rectangle wave can be varied between approximately 10% and 90% again lending variability to the modulation capabilities of this LFO. Voltage control can be used to vary the pulse width as well. If you power your circuits with +/-15 volts then observe the recommended changes that are noted on the schematic.[more]

Posted in : Signal generator

PIC-Based function generator

The project is fairly simple in concept to use the DevaSys EZ-USB protoboard as an intermediary between a Microchip PIC18F452 microcontroller and a PC to create a computer-controlled function generator for creating various types of waveforms such as sine, sawtooth, square, and triangle. [more]

Posted in : PIC projects | Signal generator


The heart of the synthesizer is a set of 2 Analog Devices AD9850 direct digital synthesis (DDS) chips. These provide 2 channels of sinewave output which may differ in frequency and relative phase. The output stage of the synthesizer also includes separate variable attenuators for the 2 channels. These attenuators have a range of 0.0 – 63.9 dB of attenuation, in 0.1 dB steps. The user therefore has control over five parameters: 2 output frequencies, 2 output attenuations, and relative phase between the 2 channels.[more]

Posted in : Signal generator