Skema Rangkaian 2 line Crossover Aktif
The picture above shows the circuit diagram, and the NE5532 dual op-amp is used. This circuit can be operated from the same power supply as the Audio Preamp, featured elsewhere on these pages. Other dual opamps may also be used, depending on your preference. The input is buffered by U1a (the second channel can use the other half of the op-amp), and fed to the two filter networks. Each filter is a 3rd order section, and has a gain of 2. The output of each section is fed (via a 1uF polyester capacitor) to the level of control and output buffer stage. In use, the output of the Preamplifier is fed to the input of the crossover network, and the outputs are fed to their respective amplifiers.
Be careful when adjusting the level of controls, since it is easy to create a mismatch in levels between the amplifiers. I suggest that the controls be mounted on the rear panel, with their shafts cut off really short, and a slot cut into the end with a hacksaw. Once the adjustment is made, it should not require further changes in use. Make sure that the power amplifier volume controls (if fitted) are turned fully up, and try to set the crossover controls so somewhere between midway and 75%. This ensures plenty of scope for getting the levels right, and will Ensure that the preamp settings are not radically different from their "pre-biamp" days.