mini space rockers

minisr2 500px

 miniSR schemo neg minimal


printable schematics

25 sound recipes


Bass drop synthesized with C1,C2 = 0.47uF and C3=100uF

C1,C2 = 0.47u C3 = 100u

Blip sound with C1 = 100nF, C2 = 22nF, and C3=1.0uF

 C1 = 100n, C2 = 22n, C3 = 1.0u

Mini Space Rockers

Here are over 80 electro drum / noise samples from the mini space rockers circuit…  but you should build it because its analog and its cheap, so no excuses.

mini space rockers samples

 mini space rockers samples (zipped 16 bit .wav files)

The .zip file is raw recordings.  Its different than the .mp3 file which has EQ, distortion, comp.


how to build mini space rockers

These instructions explain how to hand-build the circuit on a piece of perfboard, also known as protoboard. This incredibly useful material has a grid of holes at 0.1″ intervals and a copper circle (pad) around each hole.  I suggest this type.  Its also available thru MPJA.

First choose which sound you’re going to build. Click the 25 Sound Recipes link, above. Thats how you determine what values to use for capacitors C1, C2, and C3. What they do: C1 and C2 set the pitch range and affect the pitch envelope. C3 determines the decay time of the sound. I’ve tried up to 100uF here, which gives some looooong sweeps.

 parts list

Solder all the parts into their correct places, using the following two illustrations as a guide.  Make sure you’ve centered the circuit on the perfboard, so you dont run out of room on one side as you progressively add the parts…

The dotted lines show where your off-board wires will attach.  For TRIG, you can just use an SPST button, or the other options shown in the schematic above.  9 VOLT can be a battery snap.  OUTPUT can be a 1/4″ jack, with (+) connected to the tip, and GND connected to the sleeve of the jack.



After you have all the parts in place, start making connections.  The following illustration shows all the connections you can make by bending the components’ leads, trimming them to a suitable length, and then soldering them together.  Trim the excess length from the leads after you solder them.


After that, connect the points that will make up the circuit’s ground (GND) network, combining the lead-bending method you used in the last step, plus some additional wire for the longer runs.


And finally, there are a few more connections to be made with additional wire.  I run the wire on the underside of the board.  This keeps the top side looking sharp, and also makes it easier to see whats going on when you look at the bottom side.  Here are the connections where you’ll add wire, shown in green.  The connection in the top left corner can be made with un-insulated wire… but the other two should be done with insulated wire.


Ok…  If you build it I’d like hear a recording!