Building a DIY 5.1 Audio Video Receiver – Part 7

Now that I have the front speakers, rear speakers and sub-woofer working, the next thing I wanted to do in my DIY AVR project was to bring up the center speaker. I ordered a TPA3118 amplifier board for Rs. 379 towards it. The only problem with the board (which I did not realize when I ordered it) was that it does not have a volume control. The repercussions of this mistake will soon become clear. Anyway, I connected the board to a 12V power supply. The same one that was powering the crossover board from my previous post. Output from … Continue reading “Building a DIY 5.1 Audio Video Receiver – Part 7”

Building a DIY 5.1 Audio Video Receiver – Part 6

In the last post I mentioned that I was looking for a crossover board. The one that I purchased is putting out a huge DC bias and I was not comfortable using it on my sub woofer. Wondering if it is a problem with the particular unit that I got, I ordered a replacement. Unfortunately, even the replacement has the same signature output. So I decided to do something about it myself. AC coupling capacitor For those of you who have done electrical engineering might recognize that adding a capacitor in series with the load will block DC offset. This … Continue reading “Building a DIY 5.1 Audio Video Receiver – Part 6”

Building a DIY 5.1 Audio Video Receiver – Part 5

So far I have finished bringing up 4 of my 5.1 speakers in my DIY 5.1 AVR project. If you missed, check out part 1, part 2, part 3 and part 4 of the series. Next I wanted to bring up my sub-woofer. Since I have an active sub-woofer, I did not need any amplifiers to drive it. I just need to connect the output signal from my audio source directly to the sub-woofer input. But there is a catch. If you connect the audio source directly to the sub-woofer, the sub would be wasting a lot of energy which … Continue reading “Building a DIY 5.1 Audio Video Receiver – Part 5”

Building a DIY 5.1 Audio Video Receiver – Part 4

As I mentioned in my last post, after measuring the frequency response and testing the TDA 7498, I decided to buy one more. The board I bought earlier did not have the right LC filter for a 6 ohms speaker. It was designed for 8 ohms speaker. So I decided to use that board for my rear surround speakers which were also 6 ohms. However, it is fine to have a slightly poor quality amp for the rarely used rear speakers. Then I set out searching for another TDA 7498 speaker amplifier board with a 680 nF capacitor RC filter. … Continue reading “Building a DIY 5.1 Audio Video Receiver – Part 4”

Building a DIY 5.1 Audio Video Receiver – Part 3

The TDA7498 class D amplifier board that I purchased to power my front speakers was working great. The audio quality is at par with what my Pioneer 5.1 AVR delivered using class AB amplifier. I could not tell the difference in audio quality. None the less, I wanted to make sure the quality is really as good as my ears led me to believe. Enter a function generator and oscilloscope to make sure the frequency response is satisfactory over the range of audible frequencies (20 Hz to 20 kHz). If you don’t happen to know, a class D amplifier uses … Continue reading “Building a DIY 5.1 Audio Video Receiver – Part 3”

Building a DIY 5.1 Audio Video Receiver – Part 2

If you did not read part 1 of building a DIY 5.1 AVR, I suggest you start from there. Here is some important points from my previous post — decided to go with a class D amplifier start with a 2-channel amplifier for front speakers the front speakers are rated at 130W and 6 ohms After searching through a lot of class D amplifier chips, I finally decided to go with TDA7498. They are rated for 100W at 6 ohms and that should be sufficient. Although I have the 130W speakers, I never really ran them at full power, so … Continue reading “Building a DIY 5.1 Audio Video Receiver – Part 2”

Building a DIY 5.1 Audio Video Receiver – Part 1

Alright, you already know the story of my electronics going puff during a power surge. One of the electronics that got burnt was my unnecessarily expensive Pioneer 5.1.2 AVR. The reason I put emphasis on unnecessary is because I rarely used all the features of the device. Don’t even know why I spent all the money :). After it stopped working, I opened and checked everything that I could figure out. But I didn’t notice any obvious problems. The AVR just boots up, turns on the amplifier relay and turns off. Since it failed during COVID lock down, I couldn’t … Continue reading “Building a DIY 5.1 Audio Video Receiver – Part 1”