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 by Philips 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.
Description of pre tonal circuit with IC TDA1524A Stereo – With adjustment Bass, Treble, Balance, Volume and Loudness
The circuit TDA 1524 has a 20DB gain and control tone +-15dB, if you prefer to mount it in a DIP socket 18 to facilitate maintenance.
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.
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Schematic of the preamplifier with tone control and Volume
Suggested of the printed circuit board for the preamp with IC TDA1524 – Bass, Treble, Balance and Volume
List of components for assembly circuit TDA1524A tone control with Bass and Treble
|Resistor’s 1/4 Watt 5%|
|R1||1.2K – Brown, Red, Red, Gold|
|R2||2.2K – Red, Red, Red, Gold|
|R3, R4||4.7K – Yellow, Violet, Red, Gold|
|R5, R6||220 – Red, Red, brown, gold|
|C1||4700µF/35V – Electrolytic Capacitor|
|C2, C4, C5, C6, C7, C8, C20||100nF – Polyester Capacitor|
|C3, C13, C14, C15, C16||10µF/25V – Electrolytic Capacitor|
|C9, C17||47nF – Polyester Capacitor|
|C10,C18||15nF – Polyester Capacitor|
|C11, C12||10nF – Polyester Capacitor|
|C19||100µF/25V – Electrolytic Capacitor|
|D1, D2, D3, D4||1N4004 or equivalent – rectifier diode|
|IC1||7812T – Positive voltage regulator 15 Volts|
|IC2||TDA1524A – Integrated circuit with volume and tone control Philips (NXP) Semiconductors|
|IN||Input Connector Stereo Audio|
|AC||Connector to the transformer|
|OUT||Connector for Stereo Audio Output|
|J1||J12MM – Jumper 12 mm piece of wire.|
|Trafo||Transformer 12 Volt|
|P1, P2, P3, P4||50K or 47K Linear Pot-|
|S1||Switch for Loudness|
|Welding, Wire, Cash for housing circuit, printed circuit board, the IC socket, fuse, etc..|
Download PDF files for this project: PCB, Silk, Layout, Layout components, Datasheet TDA1524A, TDA1524A Eagle Library.