Preamplifier adjusts the power level of the amplifier in accordance with the source signal and allows to shape the frequency characteristics of the low-frequency path. We present a simple and easy-to-use stereo, which allows you to adjust the treble, low frequencies, balance and strengthening. The "heart" is a set of integrated circuit TDA1524. All amendments are introduced into the signal path by using the DC voltage – this reduces the likelihood of interference. The device is particularly suitable for the construction of electro-acoustic amplifiers.Specifications
- built-in stereo system subwoofer preamp
- stepless regulation of high and low tones, strengthening and balance
- all settings with a constant voltage
- single rotary potentiometers, used to adjust
- very simple assembly and start-up
- power supply: 12 DC
The scheme is based on an integrated circuit TDA1524A – Stereo audio preamplifier with adjustable gain, balance and tone via DC. On the picture 1 shows a scheme of the device.
Regulating potentiometers are supplied from the internal voltage source, which voltage is available at terminal 17 system. Replacing the capacitor C5, C6 allows to change the low frequency range, and C9, C10 to modify the treble. The input stereo signal must be connected to terminals InP / GND (right channel) and InL / GND (left channel), and the output signal is available through terminals OutP / GND (right channel) and OutL / GND (left channel). When the supply voltage 12 The maximum input level is about 6 VPP. the preamplifier circuit assembly is shown in Figure 2.
Assembling should not be problematic even for beginners. The only thing, what to look out for – is correct polarization components and their values. when the connectors + 12 AT / GND collected, must supply power + 12 DC. The preamplifier does not require programming and configuration, however, after the power supply switching is ready for use.
Note: when the wire 17 closed via resistor R5 (2, 2 KB) the ground, preamplifier transmits the signal without changing its characteristics and volume.