Introduction
Are you tired of your music sounding like it’s been played through a tin can, all because of the annoying distortion that plagues your amplifier circuit? Well, worry no more because we’ve got a solution for you! The constant volume FET amplifier circuit. With its ability to provide a constant amplitude output signal for varying input signal levels, this circuit will have you enjoying audio the way it was meant to be heard – clear and crisp, without any annoying distortion.
While traditional nonlinear amplifiers offer a close-to-constant output amplitude, the distortion can be a significant drawback. The constant volume FET amplifier circuit provides an elegant solution to this problem. In this blog, we will dive into the details of this innovative circuit and explore how it works.
With the information in this blog, you can quickly implement the constant volume FET amplifier circuit in your projects and take your amplifier game to the next level.
Hardware Required
You will require the following hardware for Constant Volume FET Amplifier Circuit.
| Components | Value | QTY |
| Polar Capacitor | 1uF | 3 |
| Resistor | 10k to 10M, 10k, 1M, 330k, 22k | 1, 1, 1, 1, 1 |
| Transistor N-channel JFET | 2N3819 | 1 |
| Diode | 1N4148 | 1 |
Circuit Diagram
Working Explanation
The key to this circuit’s success is using the FET (Q1) and its associated components as the nonlinear element. When a small input signal is applied, the FET’s gate receives a minimal negative bias. Causing the resistance between the drain and source to be high, resulting in a high voltage gain.
As the input signal increases, the gate of the FET receives a more negative bias, lowering the resistance between the drain and source and causing the voltage gain to decrease. This self-regulates the output signal to remain constant between 1.5V and 2.85V over a range of 50:1 difference in the degree of the input signal. All without producing audible distortion.
The value of R1 is established based on the optimum expected amplitude of the input signal. Hence, typically set at 200k volt RMS per decade. For example, to handle up to 50 Vrms signals, R1 should be set at 10M.
Final Words
The constant volume FET amplifier circuit is an effective way to produce an output signal of constant amplitude while minimizing distortion. Using a FET and associated elements to restore the nonlinear ingredient makes it a superior alternative to traditional nonlinear amplifiers. Try out this amazing circuit, and if you have any questions, our comment section is always there for you. Happy building!
