A 'Bon Tempi' version of a common drum toy that
comes in a variety of shapes, but with (almost) the same features.
Four drumpads and a start/stop button for a 'demo' auto rhythm,
that plays variations for two bars when drum pads are pushed while
the rhythm is playing. The circuit inside was a 'black blob' with
nothing more than one timing resistor to mess with. Painted in metallic
Speed/pitch: A potentiometer placed instead of the
original timing resitor makes speed/pitch variable from grinding
slow to furious fast.
Lightcontrolled pitchbend: A light dependant
resistor is placed in series with with the potentiometer to give
lightcontrolled variation of pitch/speed. Changing the amount of
light that reaches the LDR, by moving your hand above the LDR or
waving the BabyDrum around, is a fun and bodily intuitive way of
playing the BabyDrum. A toggleswitch lets the LDR be bypassed.
Line out: A line out 6,3mm jack socket in parellel
with internal speaker. Output level can be adjusted by a small trimmer
potentiometer mounted inside the box. Through a hole next to the
jack socket, it can be turned with at small screwdriwer.