One day I wanted to build a simple FX for didgeridoo. I did a search for a suitable processor for this task. I found FV-01 Spin Semiconductor 24-bit studio-quality DSP processor. The manufacturer processor also provides an evaluation board. It's much easier for me to write algorithms and design of the device.
IC can be connected to an external memory where I could upload algorithms. Writing the various algorithms is relatively easy for the FV-01. I was able to achieve some interesting effects. Pitch Shifter which nice working in real-time changes the pitch of the sound and an scratching FX. It works better than vinyl on Technics :) The rest is various types of flanger, delay, echo, etc. I did 3 FX banks and each bank has 8 effects, also added one more processor to handle the LCD display. There you can see which bank is used and how FX (name FX). You can see the levels of the individual effects and change their values using 3 potentiometers and 4 buttons.
At one time, you can easily combine different effects. Video shows some of the features of the first version of the device. For example is didgeridoo sound. Although it works well with the synthesizer, vocals etc.
As usual for me. I built several versions of this device :) There is also a version with one bank FX and a small LED display.
I'm in the process of expanding unit where I want to have 100 different FX and potentiometers I replace at the encoder. Where most of the parameter changes will be take place at digital level.