electronic drum brain.

[Hobgoblin_612]

I am investigating the viability of making an electronic drum synthesizer.  I want to be able to load custom .wav or .mp3 files in for each trigger and have them played when the pezio sensors are hit. I'll need about 10-16 separate channels, each with a few seconds of high sample rate audio.The sensor side of things is well documented and can be as simple as a zener diode and a 1M resistor connected to the ADC input of a micro. The main problem is that I need to play many samples at once (many drums are often played at once) so while there are many audio modules out there, none that I can find play more than one file at a time. Sparkfun has a breakout for a MIDI synthesizer chip which has a maximum polyphony of about 30 sounds but I can't load custom samples into it. I should add that i wnt the unit to be stand-alone.(no computers once completed)

My current idea is complex but may work. It uses a series of ram chips and DAC's to play each of the samples which are loaded into  them at start-up from an SD card by a micro.
The outputs of each DAC are then mixed together and fed to the output. this of course requires address and clock signals for every channel and may even need a main micro and slave micros on each channel. 

I have considered using those sound recorder chips but I don't know of any that allow sounds to be "programmed" in (as opposed to recorded)

It would be interesting to know how commercial "drum brains" work if anyone knows.
Any ideas(or reasons my current scheme won't work) are welcome as this project is still in the ideas stage.

ps. I am a drummer

[bilko]

I would have thought a wavetable sound chip is what you may be looking for, remember the old Creative AWE32 with wavetable, you could record samples and play back. Take a look here http://www.creative.com/oem/resources/Chips/EMU8030.pdf