20W Class A Amplifier - How to Select the right Transformer

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  • Опубликовано: 12 дек 2024

Комментарии • 44

  • @nicoras8803
    @nicoras8803 3 года назад +4

    Sorry for butting in to everyone's comment, that is your job, but I am enjoying your series so much that I cannot help butting in.

    • @KissAnalog
      @KissAnalog  3 года назад +1

      Thanks Nico for doing that - and please continue sharing your knowledge. I hope more will do the same. Actually I’m starting to have a difficult time keeping up;)

    • @amplidude101
      @amplidude101 3 года назад +2

      I concour, keep "butting" Nico, it's nice with different viewing points

  • @ianhaylock7409
    @ianhaylock7409 3 года назад +4

    Bored with your amplifier video's? NEVER! Watching you analyse the amplifier and calculate the requirements is the most interesting video series you do. I do think you are going to get voltage sag with low frequencies using the smaller transformer, but I wait with bated breath for the following videos to see the outcome.

    • @KissAnalog
      @KissAnalog  3 года назад

      Thanks Ian - I appreciate you! Once I start powering the amp with the AC/DC power supply l- It will be interesting to see what happens;)

  • @sunuk1915
    @sunuk1915 3 года назад +2

    Very useful for all amplifier lover's
    Thank you for new episode 😍

  • @mosfet500
    @mosfet500 3 года назад +3

    Thanks Eddie, always fun!
    The first thing I do is simulate it, then I test it empirically. Those class 'A' amps don't have much PSRR , I'd be very concerned about any ripple over 0.5 volts.

    • @KissAnalog
      @KissAnalog  3 года назад

      Thank you! Great feedback! I like your method - it is the way I go about it mostly;)

  • @t1d100
    @t1d100 3 года назад +2

    A good rough draft of the needed considerations = a good starting point.

  • @amplidude101
    @amplidude101 3 года назад +3

    🤩you passed the magic 10000 subs 👍

    • @KissAnalog
      @KissAnalog  3 года назад +1

      Yes! Thank you Thomas - that's awesome!

    • @sunuk1915
      @sunuk1915 3 года назад

      Please share link with all friends, I'm doing
      Thank you

  • @trichau9225
    @trichau9225 9 месяцев назад +1

    Your video is so helpful. ❤❤

  • @nicoras8803
    @nicoras8803 3 года назад +4

    I am enjoying following your reasoning. Just to refresh your memory, capacitors stores energy, that will give you the extra energy when you need it, just increasing the rails slightly increases the stored energy proportional to V². That is desirable so go for the higher voltage even if it is the smaller transformer. Dynamics and RMS does not fit well, dynamic and available energy does. Well done so far Eddie, you are a star. Also keep in mind that the higher rail stretches the linearity as well you have demonstrated it perfectly.

    • @KissAnalog
      @KissAnalog  3 года назад

      Thanks Nico! Great feedback! I appreciate you!

  • @versace885
    @versace885 3 года назад +2

    Hi Eddie, sure enjoy your tutoring. Thank you for another great video.

    • @KissAnalog
      @KissAnalog  3 года назад +1

      Thanks, I appreciate you!

  • @amplidude101
    @amplidude101 3 года назад +3

    I copied your plastic cover protection idea, I'm power testing a new super leach amp, 140 volt between rails, and 200000mf, that's alot of energy if something decides to short out. Great video again eddie, one more thing, did you send that aleph5 simulation?

    • @KissAnalog
      @KissAnalog  3 года назад +1

      Thanks! That is a ton of energy! Yes, did you get them?

    • @amplidude101
      @amplidude101 3 года назад

      Yes I've got them, thanks a bunch..👍

  • @hopje01
    @hopje01 3 года назад +1

    Also, a lineair power supply has quite short high peak currents between the transfo and the caps. Several times the average current consumption. This is because the caps can only be charged in the ripple period. When the caps have a higher voltage than the time in de sinus, they can’t be charged. So a transformer VA must be 2/3 times the average current delivery of the power supply.

    • @nicoras8803
      @nicoras8803 3 года назад +1

      Good rule of thumb.

    • @KissAnalog
      @KissAnalog  3 года назад +1

      Thanks Eddy (great name;)! I actually did a video in the early days LOL I haven't been doing this that long...;) ruclips.net/video/1sV0xicp4zA/видео.html

  • @johnsweda2999
    @johnsweda2999 3 года назад +2

    You need to do a listening test using less caps or small values will give you a better inductance value overall

    • @nicoras8803
      @nicoras8803 3 года назад +2

      How do you figure that, what does inductance have to do with listening -please explain. Are you talking about the transformer's inductive reactance? This does not matter after you turned it into DC then the inductance will also be a store of energy and reject ripple.

    • @KissAnalog
      @KissAnalog  3 года назад

      Yes listening tests are great and I’m relying on my friend to help with that;)

  • @gerardregnier3457
    @gerardregnier3457 3 года назад +2

    There appears to be a compensation problem. The peaks of the yellow trace (Voltage across the 8-ohm load) shows high-frequency oscillation. This problem is separate and apart from THD. It looks like you really have two issues going on, high-frequency oscillation and non-linear distortion.

    • @KissAnalog
      @KissAnalog  3 года назад +1

      Thanks Gerard - great eye! I’ll have to take a closer look.

  • @TRONMAGNUM2099
    @TRONMAGNUM2099 3 года назад +2

    Can you test both easily? Not sure will sound better. I am leaning toward the 160 Vac just because I think it will be enough to power the amp properly. I am trying to not use RMS anymore. I used it a long time before you mentioned it doesn't exist.

    • @KissAnalog
      @KissAnalog  3 года назад

      Thanks Tron! I'll see if I can - I'm sorry I'm so late getting the next video out...

  • @Daveyk021
    @Daveyk021 3 года назад +3

    I'm really not in to audio amplifiers, but I am enjoying this. I have always been of the philosophy, the bigger the power transformer the better, even if you don't need the power. I have no scientific or empirical reasoning behind that. It's probably more the Tim The Tool Man Taylor thought process "More power...urrrgh urrgh urrghh". I would think you will have less load ripple issues with the larger transformer. You are saying 10 watts more in the box. Is that more power you have to dissipate? If you are not having to dissipate those 10 watts in the form of heat, that they are just there, available if needed, then where is the harm? Also, it sounds like you are not planning to regulate this supply, so there should be no extra power dissipation in that scenario. If you find, you need to regulate it, then you need those 5 volts of over head to do that. You may of had a video on that already. Why do you not need to have a regulated power supply? Is that just the way of the audio amplifier beast? Forgive me, my electronics work and career never got in to that and it's been 40 years since school (wow, damn).

    • @nicoras8803
      @nicoras8803 3 года назад +2

      You are right most of the way. You do not want to regulate a power supply for an output stage, that is just a waste of energy, the capacitors in the rails can provide instantaneous energy when needed.
      Bigger is not necessarily better. What one does want to regulate is the front end, which in this case is done by the zeners and its capacitance. However, I would add a series diode into each power rail of the op-amp simply to prevent current rushing out of the op-amp circuit which will adversely affect its output voltage swing when the main supply falters under load.
      This could increase the third order products since it suddenly experiences compression. The third order products refer to intermodulation (IMD) distortion, not harmonic distortion, a very different animal altogether. It is a result of two adjacent signals generate two or more signals on either side of the original signals, and is not harmonically related to either but the sum and difference of the two adjacent signals. Very much an effect of compression setting in and sounds horrible. It does not matter whether the amp is class A, B or whatever class it is, gain compression is evil.

    • @KissAnalog
      @KissAnalog  3 года назад

      Thanks for watching. I did a lot of videos on the amp, so I hope you made it through;)

  • @JasonLeaman
    @JasonLeaman 3 года назад +1

    Are you doing a CRC psu for the Class A amp Eddie ?

    • @nicoras8803
      @nicoras8803 3 года назад +1

      I would then rather do a capacitance multiplier to dive just under any ripple that may exist, but is this necessary, when Eddie is done we can re-evaluate what could be improved upon or what is wasted.

    • @JasonLeaman
      @JasonLeaman 3 года назад +1

      @@nicoras8803 CRC is best for Class a Constant current amplifiers.

    • @KissAnalog
      @KissAnalog  3 года назад +1

      I'm posting a video tomorrow on the power supply ripple - it is pretty interesting I think;) Then, I'll have to post a video showing how I can correct it. I'll probably use the Kiss method;)

  • @nicfab1
    @nicfab1 3 года назад +1

    Random question, is there actually a .com website? The only one i manage to find is an empty wordpress template

    • @KissAnalog
      @KissAnalog  3 года назад

      Great question! I have had 2 friends try to build one for me, but ty have both moved in the middle of the project... I'll try to get it up this summer;)

  • @__--JY-Moe--__
    @__--JY-Moe--__ 3 года назад +1

    tired?? well judging the ''thor's thunder coils'', and several 400v capacilors. sitting promiscuously on U'r bench...I'd say u'r moving toward's 400-1200watt...that's in ebay watt's 🤣''mosfet''?? super junction mosfet!!! tangent amp?? u'r gaining more momentum each video!!