First: building an instrument is fun, and, once finished, a deeply satisfying experience.
Second: There are almost no drum computer diy projects on the web. With this project i hope some give something back to the synth diy community of which i benefitted a lot during my first synth diy projects. I will post some information on these later on.
Third: A self-built instrument is very easy to use is the since you built it the way you want to have it.
Before starting the first sketch of a schematic i put up a list of general features the drum synth should have. The basic concept is a step sequencer based drum computer with analog sound generator circuitry. The pattern control and programming is done with atmega8 microcontrollers. These are chosen because they are relatively cheap and they can be programmed with very little extra hardware required. The following sound modules will be built:
->Open and Closed Hi-Hat
The sequencer should have 16 steps, it should support 4 running modes:
->forward (the standard one)
-> forward followed by backward
Beside a clock is supports also a manual advance mode. A 'swing'-mode which enlarges every second note period is not planned currently. The sequencer will be able to control eight instruments whereof six are integrated in the drum synth. The sequencer will have a trigger output to control external equipment. One instrument control line is reserved for a digital sample player which might be added later on. Each trigger pulse will have a normal and an accentuated mode, the amount of accent will be tunable for each sound module separately.
There will be the possibility to store 4 patterns in the internal eeprom of the atmega8's. It won't feature a 'song-mode', i.e. the ability to store a sequence of patterns since it is designed as simple instrument which will be played as 'life' as possible. But we'll see, maybe i add that later on. However it supports playing one pattern while programming another one, as many things else this is shamelessly copied from the tr-808. Thats it so far. Next i will some sound clips of the prototypes of the snare and bass drum modules since i already built as well as some information on my finished synth projects, schematics etc. Beside electronics i play music solo and in a band.