Circuit Preamplifier TDA1524A
Stereo preamplifier circuit based on the Integrated
Circuit TDA1524A. Contains components for amplification and pre Tone controlling. The signal processing is done by the voltage controlled TDA1524A.
This manufactured IC (NXP) Semiconductors, allows for tone control voltage and can be used in more complex designs using microcontrollers. Here we use linear potentiometers to control tone, volume and balance. The circuit is completed with the source and the suggestion of the printed circuit board, to facilitate assembly. Ideal circuit to be complemented by the power
amplifier circuit posted here on the blog.
The power supply uses a transformer 12V/250mA to regulate the voltage at 12 volts using a IC 7812T (any prefix). If using on a project that already has amplifier and a power supply, you can omit the transformer, diodes and replace by the 4700μF capacitor by a 470 or 1000μF . The LED used to indicate the active state of the circuit can also be omitted if you prefer.
S1 in the connector is to be connected to key loudness, and works well with the key turned to the R2 circuit is disabled, if you want to use this feature, simply connect a jumper in place so that the resistor R2 (2.2K) stay connected to the circuit.