“Digitally controlled 5.1 channel audio preamplifier system to increase the gain of the multi-channel PC sound cards.
This project introduces a digitally controlled 5.1 channel audio preamplifier system. This amplifier is specifically designed to increase the gain of the multi-channel PC sound cards.
The main reason for building this amplifier is the limited gain received from the ASUSXonar AE sound card with the Creative Inspire T6300, 5.1 surround speaker system. Before switching to this soundcard, we had a Creative Sound Blaster Z card which provided good audio output with the above-mention speaker system. The key motivation of building this amplifier is to solve these gaining problems.
This preamplifier consists of six TL074/TL072 preamplifier stages and PT2258 electronic volume control. The input stage of this preamplifier consists of six TL074/TL072 buffer stages. The PIC16F886 microcontroller manages the PT2258 electronic volume control IC. All the volume levels and menu options are displayed on HD44780, 16x2 character LCD screen.
All the menu navigations and volume controlling can perform using a 5-pin, EC11 series rotary encoder. An additional push switch provides to mute and unmute the audio outputs.”