[sdiy] DIY Analogue Drum Machines???

[harrybissell]

I did experiments with using Thumbwheel switches for programming
drum patterns.  A BCD switch can control three lines plus a 'little more'
a hex switch can control four lines.

Think of those lines as Bass, Snare, Tom, Cymbal and you get the idea ?

I also made some plug in cards (22pin edge connector) with a diode matrix
for preset rhythms.  MUCH easier to program EEPROM yes...

H^) harry  (those were the days...)

Metrophage wrote:

> HI Jesse,
>
> Not at all a silly question. DIY drum machines are incredibly fun. If
> you don't go too wild then they are usually far easier to make than
> ordinary synths and keyboards. You don't need 1v/octave control, you
> can get by with far simpler envelopes. So far as the drum synth part is
> concerned, you can find many great examples out there. I have tinkered
> with the DR-110 , KPR77, and Tama TS boxes a bit, the sounds are fairly
> easy to understand. Make a noise source, a simple filter, a pitch
> envelope, an amplitude envelope - put a trigger through there and
> enjoy. Even twin-t oscillators can be great fun. EPROM-type drum
> machines I think are less interesting, but they have their moments.
>
> Almost all drum machines have a digital memory, which is very handy. I
> have not really gotten involved with computer firmware yet, but I have
> breadboarded a basic drum machine with twin-t's and 4017 decade
> counters configured as trigger sequencers. Making this type of drum
> machine is simple, but can require a lot of hardware. Still, you can
> add many features which are not present in any commercial drum
> machines.
>
> Picture six sixteen-step sequencers, each with a toggle switch and LED.
> Each sequencer can be run at its own tempo, backwards or forwards, with
> a selectable number of steps. Simple, yes? And in my opinion more
> versatile than most any dedicated drum machine. Of course, this
> requires at least 96 toggle switches, a big panel with costly hardware.
> For drum voices you could make a bunch of tunable oscillators with
> envelopes. There are a lot of circuits out there based of the X0X boxes
> and such, for example. To simplify the sequencer one could replace the
> toggle switches with momentary pushbuttons which activate CMOS
> switches, and some form of memory. Then one could save patterns, or at
> least switch between them.
>
> The only drawback is, as I was saying, unless you use a microprocessor
> - you need a lot of switches. I think TomG made a drum machine with DIP
> switches for programming, which reduced the size and cost. If you
> really play it though, you might be better off with good toggles. If
> you already have a drum machine or sequencer, you can experiment with
> making your own circuits of drum sounds, and firing them from the
> ready-made sequencer.
>
> CJ
>
> --- Jesse Yoder <jojomanee at gmail.com> wrote:
>
> > This may be a silly question, but I've been wondering lately if it is
> > practical to build a DIY drum machine.  It seems like at the least a
> > fun idea to mess around with.  However, I'm kinda new to the whole
> > synth thing, so I dunno.  Hope I'm not straying OT with this
> > question.
> >  It seems to me that an analogue drum machine is basically a synth of
> > sorts, so ...
> >
> > I'm curious.  Are there any circuits out there?  Has anyone toyed
> > with
> > the idea?  Has anyone built one/tried to, etc.
> >
> > Curious in NC,
> > ~~Ponyboy
> >
> >
>
>
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