The control voltage is fed into the first half of a 1458 op-amp, this stage inverts the signal and sets the offset and gain for the right channel gain control circuit. This signal is then fed into the second half of the 1458 op-amp which inverts the voltage again and generates the signal for the left gain control circuit. The 10K trimmer adjusts the Left channel gain, set it for equal gain from both channels with 5V on the control input. Each audio stage is identical, only one is shown in the schematic. The pair of 2N3904 transistors form a differential pair that provides voltage controlled gain. The two transistors should be matched, see the note on the schematic. Each gain control stage is fed into an NE5532 low noise audio op-amp that is wired as a differential amplifier.
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This circuit is useful for audio effects and may be used as a standard plug-in module for voltage controlled synthesizers. The circuit has one control voltage input, one audio input and two audio outputs. The control voltage input can be supplied with a continuously variable voltage from 0V to 10V, 0V pans the signal to the left output, 5V pans the signal to the center, and 10V pans the signal to the right output. Taking the circuit further, it should be possible to replace the two VCA circuits in this panner with a National Semiconductor LM13700 dual transconductance amplifier IC wired as two voltage controlled amplifiers. See the LM13700 applications notes for details.
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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