Understanding Circuits - Part 2 - ECE Topics

This is part 2 of the Understanding Circuits episode. In it, we complete our detailed walk-through of key circuits in a guitar amplifier. The goal is to understand what each component and subcircuit in the amp's schematic are doing, and to condense that understanding into a block diagram. But the focus is also on key circuit-theory concepts that are applicable to most analog circuits - not just guitar amps. In particular, circuit analysis at different frequencies is explained, and often-hidden issues in real-world circuits such as impedance levels, signal levels, and gain distribution are illuminated.

[@TekCroach]

❤❤❤ excellent video. 🎉

[@Homer19521]

Thank you 👍

[@weinihao3632]

That's a great video!

[@MegawattKS]

Thank you !

[@kamleshchavan7451]

Awesome great knowledgeable video , please more video's like these , explaining different circuit's how it works , if possible please make a video explaining the data transmission between the transmitter and receiver module's e.g. 433 mhz transmitter and receiver module which controls the D.C. motor of RC car

[@MegawattKS]

Thanks for the encouragement. If you haven't seen these videos yet, please have a look at Episode 1 Part 1 in this series. It contains some overview of transmission and reception. It is not specific to 433 MHz, but is general - covering all of radio design. The rest of the series goes into a lot of depth - but hopefully the first in the series will provide a good start. studio.kzbin.infoPL9Ox3wpnB0kqekAyz6blg4YdvoEMoJNJY/videos

[@MegawattKS]

There's also a series on the antennas needed to make the radio link work: studio.kzbin.infoPL9Ox3wpnB0kqNLnCdCtWcjGq7nRVHYxKA/videos

[@robballantyne3]

Thanks again for great content! I am curious about the comments about distortion differences between semiconductor and tube amplifiers. So, first, lets ignore the intentional clipping distortion created by the zener diodes. I've always attributed the distortion in amplifiers to the large-signal models of the devices involved (maybe this is an incorrect assumption) and the extent they differ from a linear response. FETs are large signal square law devices and so are tubes. I've always thought tubes and FETs ought to have the same sound. BJTs are exponential law devices and I can see their distortion sounding different. Am I mistaken here? Thanks

[@MegawattKS]

Thanks for an interesting question! I tend to agree, but will add a few thoughts. Discrete amplifiers (those built around a single active device) should follow the IV characteristics you describe. But most solid-state amps now seem to be based around opamps or ASIC ICs, which usually have differential amplifiers at their front-end - even if it's FET based. So what happens on one half of the cycle should happen on the other I think. Hence the odd-order distortion. And most of the distortion is controlled through feedback, which cleans it up - until one reaches the supply-rail limits. The tube amps are typically single-device per stage and thus should have some even-order distortion (they also don't use feedback, so nothing to clean it up). I think that's why they have a distinct sound. Of course once they're driven really hard, theres lots of clipping - but we're focusing on the mild-distortion as you said. That behavior could be emulated with a suitable JFET as you said. (MOSFETS however are only square-law behavior in textbooks. Since about 1990, their channel lengths have been short enough that in actual devices there is only an initial square-law behavior in the first couple-hundred mV beyond threshold, and it then goes linear.)