Elenco Snap Circuits SOUND &reg - Manual (Page 33)

Project 25 Low Pitch Keyboard
Project 26
Lower Pitch Keyboard
Project 28
Echo Speed Changer
Set the 500k W adjustable resistor (RV3) to mid-range, turn OFF the left
slide switch (S1), and then turn on the right slide switch. Set the echo
level using adjustable resistor (RV). Now turn on the left slide switch, you
hear a beep signaling that you are recording. Talk into the microphone
(X1) until you hear a beep (signaling that recording time is over), then
turn off the left slide switch to exit recording mode. Push the press switch
(S2) to play back the recording, and turn the knob on RV3 to change the
playback speed. You can play your recording faster or slower by
changing the setting on RV3, and with more or less echo by changing
the setting on RV.
Recording time is 6 seconds at normal speed, but this can be changed
depending on the setting of RV3 when you are making the recording.
C2 is only used to support RV, so is only connected on one side.
Use the preceding circuit, but replace
the 1
m F capacitor (C7) with the 470 m F
capacitor (C5, “+” on left). Press one of
the green keys and hold it down; all you
should hear is a click every few seconds.
Use the preceding circuit, but replace the
0.1
m F capacitor (C2) with the 1 m F
capacitor (C7). The pitch of the green keys
is much lower now. See how the blue and
green keys sound when pressed together.
Build the circuit as shown. Turn
off the left slide switch and turn on
the right slide switch (S1), and
press some of the green keys.
Now turn on the left slide switch
to add the 0.1
m F capacitor (C2) to
the circuit, and press some green
keys again. The pitch (frequency)
of the sound is lower now. The
blue keys will not be affected.
Compare the sound for blue and
green keys at the same place on
the keyboard (such as
C to C , F#
to F# , or B to B ). Turn the TUNE
knob to align a pair of blue/green
together, or to take them out of
alignment. Experiment to see
some interesting effects.
Adding the 0.1 m F capacitor lowers the frequency
(pitch) of the sound produced by the green keys,
and makes them similar to the blue keys.
Project 27
Very Low Pitch Keyboard
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