amplifier2
another amplifier based on the TDA7294
Edsard Boelen, 18 july 2009
At the moment I Have a 500W amplifier next to my tv, it is a bit overdone for a tv set, also the 2x32 band graphic equalizer takes to much space. The amplifier from my old project is still working fine, but it is time to make it again, and then better, because now I have enough money to buy decent components.
The idea
The system will consist of 2 parts, a pre amplifier and the main amplifier. The pre amplifier will be based on the TDA1524 there will also be a stero vu meter from 2 lm3915's. The main amplifier is build with 2 TDA7294 IC's and a powerful toroidal transformer. below is a simplified schematic
The pre amplifier
below is the schematic for the pre-amplifier and vu-meter. the main part is actually the tda1524 with some support components.
here is the finished board:
and in a nice case:
The amplifier
The most expensive part of the main amplifier is the power supply, I will use a
2x25V 5A toroidal transformer, and 2 decent 10.000 uF capacitors.
After that there will be a TL072 based volume control for each channel.
And as last there will be 2 amplifier units the schematic will be as follows:
here is the first channel
here is the final case
and here is a nice picture of the front panel
the 3 amplifiers next to eachother:
