Phase Inverters....for the Common Man

Comments · 1.8K

• ZE

  @zeerust2000 · 5 years ago

  The great thing about Uncle Doug is that he tells you what you need to know and not what you, right now, don't need to know.  I wouldn't be surprised if he's got a teaching background of some sort, because these videos are so well done.

  40

• DA

  @danweston6109 · 2 years ago

  My god man, i've been searching for this and you. Finally someone who understands what is going on and can explain it in a way normal people can understand. You're a rare breed Doug.

  16

• JE

  @jenniferwhitewolf3784 · 1 year ago

  As an EE, I have an appreciation for the use of precise language in all things technical. Although it has become common usage to refer to a circuit that creates a reverse acting mirror image copy of a signal, as a "phase inverter", these circuits really have nothing to do with phase. Phase is a relative measurement of time, expressed as a the number of degrees of a specific fixed frequency ( or period) repetitive waveform, that one waveform is time delayed by.  If you have a sine wave with repetition rate of   5 milli seconds, and another identical waveform that is offset by 2.5 milliseconds, the 2 waveforms will mirror image and appear to be 180 degrees apart. Now we change the frequency ( period ) of both signals,  to 7 milliseconds but we keep the same time delay between both of them, the 'phase' relationship is no longer mirror imaged in time, and the number of degrees delay between the waveform is no longer 180 degrees.  As engineers we know that 'phase' is a time relationship.  In the most precise technical use of language a circuit that makes a mirror image of any frequency, or even complex waveforms with no repetitive aspects, like real music, is a "inverter" without respect to any fixed time delay. We all know the common usage of 'phase inverter' to describe these circuits and even use those words, what at the same time knowing there is no intentional phase component of the mirror image signal made from the original signal.  The same thing happens with reversing the leads on a speaker driver, .. you are not reversing the phase, because there is no time delay involved, you are reversing the polarity.... but we use the word phase.  There are aspects of electronic engineering where real phase, the delay in time, of one signal relative to another is very important, usually in very very high frequency world where the time it take a signal to move in inch or 2 along a wire is incredibly significant, and we drop into using the technical use of the word "phase".  It's funny and complicated that we use that word "phase" both correctly, and incorrectly, by deliberate intention. Such is just one of the complexities of real engineering, where old 'conventions' of language use are blended with strict technical interpretations and definitions. In the practical world, Doug IS using the language that even EEs use, even though when we use those words we know there is no phase time delay aspect to a phase inverter.  😊.  Students of amp design take note: Doug has provided here the single best description of how these circuits function that I have ever seen, I have in the electronics game for half a century. You have a superb teacher here, study his educational materials.. There are precious few that have the knack of getting concepts across like Doug.. he IS a real gem👍.

  21

• ER

  @EricDobsonTV · 2 years ago

  I’m going back and watching all the tech videos in order. They’re so insanely good. So clearly explained. They’re connecting a whole lot of dots I’ve picked up over the years from other sources. Thank you for making these!

  4

• AN

  @andypendlebury6445 · 5 years ago

  Thanks Uncle Doug, I love watching your presentations. They are some of the most detailed and clearest examples I have found anywhere. I've read books, watched lectures, but I've learned the most from you. So Many thanks for that, it is well appreciated. Your'e a real hero for amp lovers. Best wishes!

  19

• TH

  @themysticchild_official · 3 weeks ago

  The best tube amp lessons I’ve had. Thank you Uncle!

• KE

  @keithcoltron3171 · 5 years ago

  As an electronics engineer I still found this fascinating, Your description and explanations are just simply superb, I have tried on many occasions to 'teach' others but I'm afraid I just can't explain it like you, you just seem to explain things in a way that I'm sure anyone could understand, I knew what was coming next but still enjoyed it so much, it's the way you put things that makes so much difference and for people that want to learn it's an absolute must, being able to picture the process in your brain should turn anyone's light on! really well done and thank you for all you do, it's invaluable, if you haven't done any teaching in the past then we've all missed out! You're a star in a somewhat dark and otherwise confused universe.

  13

• JW

  @jwren51 · 3 months ago

  Hi Doug, I'd just like to thank you for this excellent series. After watching your videos on how tube amps work I built a Champ clone for my grandsons 18th birthday and then a Marshall 18w push/pull clone for myself. I had a background in electrical control panels but knew nothing at all about tube (valve) amps. The knowledge you imparted was invaluable in tracing errors and checking the bias etc. You have a rare talent as a teacher. Thanks again.

• MA

  @markbunch5062 · 5 years ago

  Gosh, I've spent such a happy weekend with some of your videos.  They are beautifully paced and pitched at exactly the right level for me.  Thank you.

  4

• C_

  @C_Dana · 4 months ago

  Hey Uncle Doug, didn't know I had an uncle named Doug! Your videos are fantastic. I designed my first tube amplifier about 50 years ago. Just retired after 45 years as an engineer and now want to go back to those times of tubes or valves(those Brits....) and design a real power amp, one that will heat a room! Your videos served to refresh my memories on how tubes work and how to invert signals for a Class AB amp. Thank you Uncle Doug!

• DA

  @Dan79istheman · 12 years ago

  "I am such a fan!, cause' Uncle Doug is the Man!"

  9

• CH

  @christianbergeron1407 · 5 months ago (edited)

  WOW, I GO IT,  this is really for the common man. The horses thing really made it very clear, I could not stop seeing horses for all the remaining of the video. Very well done, thanks.