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Six LED Stereo VU Display

The following image is the scheme diagram of six LED stereo VU display circuit which build using Dot/Bar Display Driver IC LM3915. This VU display should be connected before amplifier module circuit. You may connect this circuit at pre-amp output, tone control input/output or equaliser input/output. This circuit powered with 12V DC supply. About LM3915:… Read More »

Hi-Fi Tone Control

This is a inexpensive high fidelity (hi-fi) tone control circuit designed just with two low cost transistors as the active components. The schematic is one channel (mono) tone control, build the similar circuit will make it become stereo channel. This Hi-Fi tone control circuit can be operated with wide range supply voltage, 12V – 24V… Read More »

Insect Repellent

This insect repellent circuit will repel insects such as mosquitoes, flies and cockroaches from your home or yard effectively. circuit uses a specific frequency to disrupt the insect so the insect will go away from this circuit. This insect repellent circuit can be placed inside or outside the home (for speakers). If you want to… Read More »

PCM2706 USB Sound Card

Here is the USB sound card circuit based on PCM2706 which dedicated for USB audio. With USB controller module inside PCM2706, there is no more additional programming to the IC. The computer system will automatically detect this circuit when connected to the USB port. You will get stereo audio channel output from this circuit. Schematic… Read More »

Audio Mixer + VU Meter

This is an audio mixer circuit which designed along with VU meter circuit. The circuit is for one channel input, if you need, for example 5 channel mixer, then you need to build 5 similar circuits. The this audio mixer uses three potensiometers to adjust volume level, low frequency (bass) level and high frequency (treble)… Read More »