How to add a tweeter to a baffle or speaker. Very simple circuit, using only one potentiometer and two capacitors, very easy to install.

This circuit has a single input and 4 independent outputs, each amplified with an operational amplifier.

This metronome circuit with adjustable BPM, allows those persons who study or are music fans, to keep the timing, quite accurately for a long period of time.

4 operational amplifiers, some resistors and capacitors to implement an audio mixer with a very simple design.

This simple 6 LED VU meter circuit allows us to visualize the level of an audio signal. Due to its few components, it is a cheap circuit and easy to build.

This circuit attempts to emulate the operation of a music box. The maximum number of notes is 10, allowing us to make a simple melody.

This 2 watt audio amplifier circuit is specially designed to consume little power and to be used with batteries or low voltage power sources.

This circuit can be used to display the variation of an audio signal in a group of 8 LEDs, behaving like a VU meter. We could use any specific integrated circuit used for VU meters, but we decided to use a readily available LM324 op amp. I.C.

This 400 watt stereo amplifier circuit uses the Sanyo STK4050 hybrid IC, a high quality low noise amplifier. Its maximum output power is 200W per channel

This circuit uses the well-known 555 integrated circuits to generate a range of sounds that are heard through a small loudspeaker.

This audio level indicator circuit is very interesting because it allows us to visualize the audio level intensity by connecting this circuit to the input of a loudspeaker.

This Microphone Mixer combines signals from 3 different sources (3 microphones) easily and economically.