Given below is an Active crossover circuit suitable for HiFi audio systems using LM833, the dual operational amplifier.
Description:
Crossover circuits come in two varieties: active and passive. Passive crossover circuits rely solely on passive components, making them straightforward but inefficient in terms of energy usage, and they can introduce distortion. Active crossovers, on the other hand, avoid these drawbacks and prove to be a superior choice for HiFi audio systems. Active crossovers divide the incoming complex audio signal into two distinct bands: one for low frequencies and the other for high frequencies. These two bands are independently amplified by two power amplifier stages, one optimized for the low-frequency range and the other for the high-frequency range, a setup known as bi-amping.
The provided crossover circuit employs National Semiconductors’ LM833. A dual operational amplifier specifically designed for audio applications. This circuit utilizes four op-amps, and thus, two LM833 ICs are incorporated. It can be divided into two sections: a high-pass filter and a low-pass filter. IC2b serves as a first-order Butterworth low-pass filter, with the low-frequency output available at its pin 1. The high-frequency output can be obtained at pin 7 of IC1a. In this particular configuration, the crossover frequency is set to 1KHz, in accordance with the formula Fc = 1/(2πRC), given the provided components.
Active Crossover Circuit Diagram:
Notes:
- Assemble the circuit on a good quality PCB.
- The circuit can be powered using a +15/-15 V DC dual supply.
- LM833s must be mounted on holders.
- R and C can be changed for getting different crossover frequencies.
The LM833-N is a dual operational amplifier that has been engineered with a special focus on optimizing its performance within audio systems.
This dual amplifier IC incorporates innovative circuitry and processing methods to offer high-speed operation, wide bandwidth, and minimal noise, all without the need for additional external components or compromising stability. The LM833-N comes with internal compensation for all closed-loop gain settings, making it well-suited for various applications, especially in preamplifiers and high-level stages within PCM and HiFi systems. Furthermore, the LM833-N is designed to be pin-compatible with the standard dual operational amplifiers commonly used in the industry.
