Dilshan R Jayakody’s Web Log

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 ASUS Xonar 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. The assembled 5.1 preamplifier PCB. 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 ...

If you are an audio enthusiast and if you have multiple audio systems and speakers, you may definitely need to have a speaker selector switch. These switches allow you to route a audio signal through a switching system and distribute it to various speakers. Using this listener can select single amplifier – speaker combination through the switch. We mainly design this switch to share our speaker system with multiple audio amplifiers. We design this switch to handle 6 stereo audio channels. Final view of 6 channel speaker selector prototype. This switch is based on PIC16F88 - 8bit MCU, ULN2803 Darlington transistor arrays and 12 DPCO relays. MCU is the core component of this switch and it control all relays, seven-segment display and store last channel in E 2 PROM memory and restore it during next power-up. In this system all audio lines are switching using 12 DPCO relays. To get optimal results we recommended to use good quality relays with thus switch. In our prototype we u...