Discrete Class-D Audio Amplifier - Part 2

This video is part 2 to my discrete class D amplifier. This time it actually works.
-- Links --
My Website: sinelab.net
Schematic: sinelab.net/pdf/discrete_clas...
Parasitic Turn-On: sinelab.net/pdf/parasitic_tur...
LC Filter Value Calculations: sinelab.net/pdf/lc_filter_des...
Buy me a coffee: www.buymeacoffee.com/thesinelab
Bitcoin Address: bc1qwlfr2ml9km4r5vhpfh7f3m60k80whhcq3ysths
Ethereum Address: 0x7e8B8Ff8D6bD8DfB48b4A139694BB343f040Bb3f
--

[@SineLab]

Watch part 1 here: kzbin.info/www/bejne/aHuaeIpvfbSrqLc

[@MattBorgardt]

Young man, I will tell you that you are going to have a fun time in life. Keep up the curious mind set. science and math are so much fun...

[@SineLab]

I have no plans on stopping anytime soon :)

[@bobwatkins1271]

Looking forward to a part 3.

[@shreeshbajpai3794]

You actually did it, what an inspiration

[@SineLab]

Thanks for watching!

[@sdjhgfkshfswdfhskljh3360]

It's nice to see design evolving.

[@wiradharma7030]

Just what i need, good topic and explanation mate. Good job mate! Subscribed, if I have spare time I will watch another topics.

[@baptisteroche8113]

This is exactly the video i needed ! I'm also trying to build a class D amplifier. After trying multiple triangle generator, i changed my mind and decided to use a microcontroler to turn audio to pwm. It will allow me to have a dsp. Thank you for all the explanations, i hope that you will continue your videos!

[@SineLab]

Good luck building your class D amplifier :)

[@vojtechadame5860]

Awesome video! This is finally a usable pruduct, congratulations.

[@SineLab]

Thanks for watching!

[@dimitrioskalfakis]

very good effort, again, as last time with good points regarding individual stage simplifications and custom adaptations. in the audio amp you could leave a portion of the emitter resistor unbypassed both for gain stability and so as to use a much smaller input capacitor and yes the mosfet problem is infamous especially with slower mosfets and large gate to drain parasitic or a pronounced miller effect.

[@SineLab]

Thanks for the suggestion. That MOSFET problem took me a while to figure out.

[@ivolol]

Congratulations on succeeding! It shouldn't be too hard to build a discrete power regulator circuit given all the experience you have, if you want to replace that LM317 in the future :) A zener, a simple opamp circuit for feedback, and a pass transistor. Although 7X09/7X12 have been mainstays in amplifier circuits for decades, so I'd agree I would hardly count it as cheating. Not sure if you'd want room in your design for a potentiometer to get the driving circuitry as close to 0V ambient as possible? And yes would be very curious to see how much negative feedback would improve distortion. You might be able to use an oscilliscope with FFT, or even a power-resistor divider into PC audio port with waveform software to measure the distortion you get.

[@andymouse]

Awesome work !....cheers.

[@SineLab]

Thanks for watching!

[@bob_mosavo]

Thanks 👍

[@dakata2416]

Good job dude!

[@xzddakfdmiug5832]

I bet heavy metal music sounds great with that amplifier!

[@SineLab]

It sounds great!

[@AntONafinogenOFF]

I'm waiting for the 3rd part. I wonder how you will make a feedback

[@smartups1]

Awesome

[@harshelectronics8182]

I'm facing same issue as you're facing @12.15. I'm attaching audio wave directly on the pin of comparator IC. Are you adding LC filter at the input stage of the comparator stage?

[@SineLab]

Yes, the LC filter is directly after the audio amp and directly before the comparator.

[@smartups1]

The 3rd part should have feedback .

[@kelvinkhe7684]

What is TP11?

[@SineLab]

It's the test point for the triangle wave before the transistor amplifier.