The main aim of this project was to design my very own home theater system. The first unit I wanted to build was 7.1 preamplifier.
Searching the net I found Mark Hennessy site with great preamplifier project. This was really good starting point.
With no need for my own researches on analog stage, I decided to expand this project with more inputs, more channels and better power supply. The unit don't provide
any kind of decoding DD, DTS etc. Surround input accepts only analog signal from external decoder, such as Denon DVD 1920 in my case.
- Tuner, DVD and AV - three analog inputs chossen by relay input selector
- XLR input on OPA2134, INA2134 and output on DRV123
- Digital input on DIR1703 SPDIF receiver and PCM1793 DAC
- Digital output on OPA1632, PCM1804 ADC and DIT4096 SPDIF encoder
- USB input on PCM2702
- Input for addictional 6 home theater channels
- Build-in analog 7.1 surround matrix using OPA4134
- 7.1 analog output
- Headphone output on TPA6120
- SPI programmer input for firmware upgrade
- Four trigger output to control external devices
- Simple remote control of all available functions
All the components were chosen carefully and are the best I could afford. All rersistors are 1% metal film. Panasonic FC capacitors used in analogue stage and Sanyo Os-Con in digital. No electrolitic capacitors in signal path. High quality telecomunication relays.
On the next page user interface...