Power rails - single breadboard

Power rails - multi breadboard

μVCO - basic connections

μVCF - basic connections

μVCA - basic connections

μADSR - basic connections

μLFO - basic connections

Manualy controled voltage

The potentiometer here acts as voltage divider. It divides the GND-5V voltage into two parts: GND-U and U-5V. We take of course the first part, GND-U, which is referred to the ground.

While turning the knob of the potentiometer, the voltage between the yellow wire and the GND changes from 0V (at left extreme) to 5V (at right extreme).

If we connect the yellow wire to a control pin (μVCA GAIN, μADSR ATTACK, μVCF FREQ, etc.) we can manualy change the value of the parameter controled by voltage at that pin.

Attenuator

An attenuator is a device which weakens a signal. The simplest attenuator (passive attenuator) may be built out of a potentiometer, acting as voltage divider. An attenuator of this type is good enough in most of situations we will encounter. (Another type of attenuator - active attenuator - is a voltage controlled amplifier.)

In this circuit, instead of constant +5V, as in previous example, we connect a - possibly time variable - signal to the right pin of the potentiometer. At each moment the output voltage is reduced with respect to the input voltage by a factor dependent on potentiometer's position.

When the potentiometer's position is at its left extreme - the output voltage is constantly 0V. When at its right extreme - at each moment the output voltage is equal to the input voltage.

Attenuator - example

In this diagram the attenuator controls how much the cut-off frequency is influenced by the ADSR envelope.

Simplest complete analog synthesizer