LM386 audio probe amplifier is an essential tool for troubleshooting audio stages in audio related circuits such as amplifiers, oscillators, function generators, phone circuits, radios and lots of our other projects. It is a very handy piece of test equipment that can be built on pre-drilled board and will make a perfect addition to your electronic collection. There are lots of things that can go wrong with an audio stage. It can produce distortion or a “hollow” sound, go weak or simply fail altogether.
Likewise tone circuits can present a number of faults and it is very handy to be able to “hear” what is going wrong.
It is not sufficient to measure the DC voltages on these stages. This only gives a partial picture of the conditions and does not tell you the quality of the audio being processed. To determine this you need a piece of test equipment that will let you see or hear what is being processed. Some of the projects you can test with the Mini Bench Amplifier are tone circuits while others are audio circuits. Tone circuits and audio stages are surprisingly difficult to test unless you have an audio probe or a oscilloscope. Oscilloscope is an ideal piece of equipment but if your budget does not extend this far, the next best thing is an audio probe.
Build Accurate LC Meter and start making your own coils and inductors. This LC Meter allows to measure incredibly small inductances making it perfect tool for making all types of RF coils. LC Meter can measure inductances starting from 10nH - 1000nH, 1uH - 1000uH, 1mH - 100mH and capacitances from 0.1pF up to 900nF. The circuit includes an auto ranging and reset function to make sure the readings are as accurate as possible ... [more]