Build A Simple Sine Wave Oscillator

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  • เผยแพร่เมื่อ 31 พ.ค. 2024
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    / theaudiophool
    This time we're looking at how to build the venerable Wien Bridge Oscillator circuit. Using some clever feedback with a self-biasing JFET. This circuit Is essentially a very high Q filter, fed back using an op-amp with positive feedback to create an oscillation. Which is then sustained by careful managing of the op-amp closed loop gain.
    Schematics: drive.google.com/file/d/1khD2...
    00:00 Intro
    00:40 Wien Bridge Overview
    02:10 Oscillator Basics
    03:27 Circuit Setup
    04:11 Automatic Gain Control
    05:13 Diode Recap
    06:22 JFETs & AGC
    09:00 Circuit Demo
    13:31 Add Voltage Control
    16:06 Summary & Next Time!
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ความคิดเห็น • 119

  • @siliconjunkie7297
    @siliconjunkie7297 2 ปีที่แล้ว +16

    Good video, Suggestion:- As you modify the circuit display the modified schematic for a few seconds so it’s clear what you are doing

    • @TheAudioPhool
      @TheAudioPhool  2 ปีที่แล้ว +3

      Will do this in the future. thanks! :)

  • @traianmunteanu3866
    @traianmunteanu3866 2 ปีที่แล้ว +36

    I really like that you used manim for the schematics and the animations explaining the concepts, really awesome stuff. Thanks for the content!

    • @TheAudioPhool
      @TheAudioPhool  2 ปีที่แล้ว +10

      I think it's a bit cleaner looking than scribbling on a whiteboard 😅
      Thanks for watching :)

    • @MohammedAyazQuadri
      @MohammedAyazQuadri ปีที่แล้ว +1

      Whata Manim?
      Awesome channel btw. Discovered it yesterday. Keep it up!

    • @sonusharma136
      @sonusharma136 ปีที่แล้ว

      4558ic bom circuit explain

  • @salvadorkda5758
    @salvadorkda5758 2 ปีที่แล้ว +13

    Finally youtube recommends me a good channel about electronics and sound.
    Great video and explanation. Gonna take a look at the rest of your content :D

    • @TheAudioPhool
      @TheAudioPhool  2 ปีที่แล้ว +1

      You're too kind! Thanks for watching :)

  • @Toleich
    @Toleich 2 ปีที่แล้ว +6

    You've been blessed by the Algorithm, friend.

    • @TheAudioPhool
      @TheAudioPhool  2 ปีที่แล้ว +3

      All praise the mighty algorithm

  • @CoolDudeClem
    @CoolDudeClem 2 ปีที่แล้ว +11

    I always used a light bulb in a wein bridge oscillator, that also seems to work well.

    • @TheAudioPhool
      @TheAudioPhool  2 ปีที่แล้ว +2

      Incandescent bulb works beautifully and is very cool :)

    • @Roderick_Legato
      @Roderick_Legato 2 ปีที่แล้ว +2

      Mr. Hewlett and Mr. Packard thought so.

  • @edgeeffect
    @edgeeffect 2 ปีที่แล้ว +5

    Those animations are excellent.... If you were just talking about currents and resistances and negative feed back.... my head would go all muzzy and I'd completely miss what you were saying.
    But with the animations, the circuit, the changing values, the arrow growing and shrinking really help to show what's really happening. Great work!

    • @TheAudioPhool
      @TheAudioPhool  2 ปีที่แล้ว +1

      Glad to hear it! Thanks for watching!!!

  • @jakesnell7707
    @jakesnell7707 ปีที่แล้ว +1

    I really appreciate how thoroughly you explain things. It’s very linear, I learned a lot from this. Thank you.

  • @shawncalderon4950
    @shawncalderon4950 8 หลายเดือนก่อน

    You are a superb instructor! I’m so happy I found your channel. You truly have a gift for teaching.

  • @Kozakjosh
    @Kozakjosh 2 ปีที่แล้ว +7

    Excellent work. I'm just now learning EE basics now with my school after working in signals analysis for a few years in the military. I'm super excited to trying and get to your level some day.

    • @TheAudioPhool
      @TheAudioPhool  2 ปีที่แล้ว +3

      That is awesome! Glad to have you along!!

  • @davidjohnston5329
    @davidjohnston5329 2 ปีที่แล้ว +1

    Yay! A new channel to binge watch!

  • @dardosordi
    @dardosordi 2 ปีที่แล้ว +7

    I'm so happy to have found your channel. This videos are great!

    • @TheAudioPhool
      @TheAudioPhool  2 ปีที่แล้ว

      Glad to have you along! Thanks for watching :)

  • @Tichondrius-
    @Tichondrius- ปีที่แล้ว +1

    Check out this oscillator topology my mentor invented: "Sinusoidal Oscillators Operating at Frequencies Exceeding Unity-Gain Bandwidth of Operational Amplifiers" is the article's title.

  • @sCealt
    @sCealt ปีที่แล้ว +1

    this is hands down the best youtube channel on DIY synths electronics. can't recommend it enough! great job!

    • @Theineluctable_SOME_CANT
      @Theineluctable_SOME_CANT ปีที่แล้ว

      Best, SO FAR...
      IF you want something really simple, or quite advanced, check me out.
      I am making content because there is so much shit on TH-cam! Dave, Fran and all the other idiots make us EEs look like fruit loops.

  • @J.D-g8.1
    @J.D-g8.1 10 หลายเดือนก่อน

    Your explanations and animations are very clear. Thx for the content.

  • @jimlake5404
    @jimlake5404 ปีที่แล้ว

    I really like the way you present circuits. You understand that the people who are interested in this material want to/need to see the schematics, and the theory, and the math. They wouldn't be here if they didn't. So layer it on thick and thank you for your time and energy.

  • @magnopere
    @magnopere 2 ปีที่แล้ว

    thank you! what a wonderful resource! I've been getting into circuitry in an audio context and it's been a bit difficult to parse the information myself. I will be following along and learning!

  • @TheSlowerMonkey
    @TheSlowerMonkey ปีที่แล้ว

    please don't stop making these videos. you're a legend.

  • @beatrute2677
    @beatrute2677 5 หลายเดือนก่อน

    Thank you very much for all the effort you put into this, I learnt a lot here.

  • @til2003
    @til2003 2 ปีที่แล้ว

    Wow. Very well explained. Great Video! Thank you very much.

  • @soletey832
    @soletey832 5 หลายเดือนก่อน

    great explanation - thank you - I'm glad YT found me this channel

  • @tiagomello
    @tiagomello 2 ปีที่แล้ว

    Keep up the outstanding work!

  • @CircularMirror7
    @CircularMirror7 ปีที่แล้ว

    Great explanations on the functions of the circuits. 😃

  • @anthonyludington8320
    @anthonyludington8320 ปีที่แล้ว

    Great video, the graphics are super helpful. 🤘🏻

  • @dannyroessler
    @dannyroessler 2 ปีที่แล้ว +5

    very good explained video as always, but now that you opened up the rabbit hole of vactrols, it would be realy great if you can dive a bit deeper onto ways of linearising vactrols befor you go on with control voltage

    • @TheAudioPhool
      @TheAudioPhool  2 ปีที่แล้ว +1

      Noted! Thanks for watching :)

  • @zapp442
    @zapp442 2 ปีที่แล้ว +1

    You have a new subscriber. Thank you very much!

  • @JLCPCB
    @JLCPCB 2 ปีที่แล้ว +4

    Great video! Very cool project! 😉

    • @TheAudioPhool
      @TheAudioPhool  2 ปีที่แล้ว

      Thanks very much :) I have used your services many a time!
      Thanks for watching!

  • @zoeyzhang9866
    @zoeyzhang9866 2 ปีที่แล้ว

    Informative video!👍

  • @overengineeredinoz7683
    @overengineeredinoz7683 2 ปีที่แล้ว

    Great explanation

  • @nikbivation
    @nikbivation 2 ปีที่แล้ว +2

    Amazing, thank you for this!!

  • @JonAndress
    @JonAndress 3 หลายเดือนก่อน +1

    Love this channel. One request, can you consider editing your videos so that we can hear the effect that we are creating at the beginning of the video? For example, It would be great to hear at the beginning of the discussion what the different wave types sound like. (sine vs sawtooth etc)

  • @nyyotam4057
    @nyyotam4057 2 ปีที่แล้ว

    Congratulations, you got a new subscriber :-).

  • @shiva.chennai
    @shiva.chennai 7 หลายเดือนก่อน

    Very interesting. Thank you. You could have expressed the value of frequency while testing. Anyway thank you so much. 17:05

  • @danielnathaniel5883
    @danielnathaniel5883 10 หลายเดือนก่อน +1

    Great job boss. Please can you make a 3 phase pure sine oscillator with 120 degree phase shift. Thanks. You just gain a subscriber

  • @acebinko1
    @acebinko1 ปีที่แล้ว +2

    I know this comment is late, but I absolutely love your videos. I like following along with the math and i really appreciate when you show multiple design choices and why and when to go that route. I see that you are taking a lot of feedback from the community and i would like to mention something if you wouldn't mind taking it into consideration. A lot of the AC frequencies you work with are within hearing range (obviously because it's within audio signal range). Do you mind addressing whether these circuits work with frequencies up to a few hundred kilohertz? I know a lot of circuits are prone to noise and attenuation as you approach this range. If you could address this that would be absolutely appreciated.

  • @christianh.5908
    @christianh.5908 2 หลายเดือนก่อน

    Man I love these detailed explanations
    Can you please link the wave shaping part you mentioned in the end?

  • @Dexter101x
    @Dexter101x 2 หลายเดือนก่อน

    Reminds me of those auditory tests

  • @grandchampignon
    @grandchampignon ปีที่แล้ว +1

    hello! love this channel, it has taught me so much!
    I tried to build this circuit, but I didn't have a j113 so i tried substituting another N-channel JFET, a 2N3819 - i can't seem to get it to oscillate. I have confirmed that if I replace the JFET with just a trimpot I can start the oscillations by turning the trimpot. do these not work for this purpose, or is there something I'm missing?

  • @tamasv1290
    @tamasv1290 2 ปีที่แล้ว +3

    Thank you for this another great video! I am not an "audio guy" but I like building audio stuff because it is a great way to learn about analog circuitry while still having a lot of fun! Your videos were a great help and a fantastic source! I hope you keep up the good work! Best wishes!

    • @TheAudioPhool
      @TheAudioPhool  2 ปีที่แล้ว

      Really glad you're enjoying them. Thanks for watching!! :)

  • @mattcorrigan6639
    @mattcorrigan6639 2 ปีที่แล้ว +3

    good stuff

  • @kamleshchavan7451
    @kamleshchavan7451 10 หลายเดือนก่อน

    Awesome explanation, sir any videos on Radio Control circuit's , explaining in detail the working of the circuit , how the signals are transmitted from transmitter to receiver to control the dc motors in the RC toys

  • @ianliston-smith7921
    @ianliston-smith7921 2 ปีที่แล้ว +1

    Nice description of the circuit. Presumably the cct will work with a CA3130 without split +V and -V? What's the formula for calculating the frequency?

    • @TheAudioPhool
      @TheAudioPhool  2 ปีที่แล้ว +1

      It should do! You need a mid-rail reference as your 'ground'.
      I do mention in passing, should have made this clearer in the video. sorry!
      As long as you have c1 = c2 and r1 = r2 the frequency of oscillation is the 3dB point of the filters aka f = 1/(2*pi*R*C).
      If you decide you want to have different values for c1 & c2, or r1 & r2 the equation becomes f = 1/(2*pi*SQRT(R1*R2*C1*C2)). Which you can see simplifies to the first equation if the resistors and capacitors match. :)

  • @robertoc.5505
    @robertoc.5505 ปีที่แล้ว

    Thanx for video, the best sub bass osc ever! I'm breadboarding it but what op amp is in the video? LM741?

  • @psynautic
    @psynautic 2 ปีที่แล้ว

    things are really ramping up (pun intended) cant wait for the next few

    • @TheAudioPhool
      @TheAudioPhool  2 ปีที่แล้ว +1

      Boom boom!
      Thanks for all your support James! :)

  • @bayareapianist
    @bayareapianist 4 หลายเดือนก่อน +1

    One problem I see which you didn't solve is the output max voltage changes by frequency. Maybe you need an optocoupler to control this too.

  • @jonayamaha3215
    @jonayamaha3215 2 ปีที่แล้ว +1

    im stupid, i cant follow you, and i fell like the day that i know enough to follow what you are saying i wont get any value because i'm gonna know what you're explaining, the video is great production and im gonna build this oscillator as a tool for audio equipment repair. About those ldr-led thingy (i didnt catch the name you call them, im from Argentina, i barely speak spanish, let alone english...i taught myself as i did with electronics repairs, who cares i know) theres a really good attenuator build called "lightspeed", i mention it because attenuator are useful and maybe is useful to you. Thanks for the video, hope someday i understand everything lol.

    • @roygalaasen
      @roygalaasen 2 ปีที่แล้ว +1

      There is a series on op amps that is explained by an old man, and while it may seem boring, the way he explains things is just amazing. I do have a feeling that if you watch some of the first videos in this playlist, you will get a better understanding: th-cam.com/play/PLL_nf1OmixTTd7rEoqoM6aJ5ZdI-V47vs.html
      Edit: I didn’t mean to offend anyone by calling anyone ‘old’. I am not so young myself lol…

    • @jonayamaha3215
      @jonayamaha3215 2 ปีที่แล้ว

      @@roygalaasen hey man, thanks for your time, ill check that out no doubt, i'm 32 on this sunday so im already started to decay too lol.

    • @roygalaasen
      @roygalaasen 2 ปีที่แล้ว

      @@jonayamaha3215 Hey! Happy birthday coming Sunday then! Oh to be 32 again! 😃

  • @biplabbanerjee3013
    @biplabbanerjee3013 8 หลายเดือนก่อน

    What is the output distortion or noise level in dB. Thanks for yr. video teaching.

  • @falconhawker
    @falconhawker 2 ปีที่แล้ว +1

    (1) Have you found ohmic contact problems when using solderless breadboards to test your designs ?

    • @TheAudioPhool
      @TheAudioPhool  2 ปีที่แล้ว +1

      Yes all the time. Very infuriating! Lots of people swear off them entirely. You just have to give everything a prod from time to time and I find it's ok for low frequency stuff like this! :)

  • @danielabayomi2794
    @danielabayomi2794 9 หลายเดือนก่อน

    sir, can i implement this circuit in an inverter to design a sine wave inverter?

  • @woosix7735
    @woosix7735 2 ปีที่แล้ว +1

    I was just messing around with the same circuit, nice. I was thinking this could make a good simple sine lfo if you have big capacitors, and there is no point for super prisice voltage control if any for an lfo

    • @TheAudioPhool
      @TheAudioPhool  2 ปีที่แล้ว

      I had the exact same thought!

  • @tziirkq
    @tziirkq ปีที่แล้ว

    How much does it matter which diode is used? Are there any diodes which wouldn't work, or in this instance could any diode be used?

  • @ConsertandoTudo
    @ConsertandoTudo ปีที่แล้ว

    One thing I like about eletronics are those "unusual" ways to use components. Even with explanation I could not really understand the jfet self oscillation part. I'm really a noob, I would use a 555, a LPF and a opamp

  • @stefanb.933
    @stefanb.933 6 หลายเดือนก่อน

    can lm 358 be used?

  • @petername2608
    @petername2608 2 ปีที่แล้ว

    Bro can you make a video on amplifier were i want to increase the voltage from 0- 45volt and 5 amps

  • @stefansynths
    @stefansynths 2 ปีที่แล้ว +2

    The animations were great! How much work was it vs the whiteboard?

    • @TheAudioPhool
      @TheAudioPhool  2 ปีที่แล้ว +2

      A lot!!

    • @stefansynths
      @stefansynths 2 ปีที่แล้ว +1

      @@TheAudioPhool Worth it?

    • @TheAudioPhool
      @TheAudioPhool  2 ปีที่แล้ว +3

      @@stefansynths Absolutely. I'm hoping that as i get more familiar it will get a bit quicker. took me about a weeks worth of evenings to do these!

  • @beasterfield321
    @beasterfield321 ปีที่แล้ว +1

    is there a way to do this with 4.5 volts and a 9V power supply? I tried this circuit replacing all grounds with 4.5 and had no luck. the best I can get is a triangle wave or square.

    • @TheAudioPhool
      @TheAudioPhool  ปีที่แล้ว

      I'll have a look and get back to you

    • @TheAudioPhool
      @TheAudioPhool  ปีที่แล้ว +2

      I'll have a look and get back to you

    • @beasterfield321
      @beasterfield321 ปีที่แล้ว

      ​@@TheAudioPhool So, I learned that you can take a single supply voltage supply like 9 volts, and voltage divide it between the positive and negative end, this gives you +4.5V and -4.5V. Then I can get the oscillator circuit to work. so if I wanted +15V and -15V, I would use a +30VDC supply and voltage divide it. There is no explanation of this anywhere online this I could find. I just had to figure it out. granted I have an associates in electronic engineering :).

  • @Mehdi-uh5pw
    @Mehdi-uh5pw 2 ปีที่แล้ว +1

    Really cool video ! Although, I was wondering, instead of using a JFET to make the total gain greater then one, wouldn't it be cheaper to use a RNTC resistor ? We replace R2 by this resistor which would have a standard value greater then 20k ohm and would then decrease to 20k ohm as the circuit increases in temperature. Thanks for the video !

    • @TheAudioPhool
      @TheAudioPhool  2 ปีที่แล้ว

      The original circuit (from the 19th century!) Uses an incandescent bulb to do exactly this. Lots of different ways to build anything! Give it a go and let me know how it goes :)

  • @malte1984
    @malte1984 7 หลายเดือนก่อน

    why is there an appearently necessary diode in your schematic (it doesn't work without it when i try it) but in the video it seems to work without it? Plus: The Video makes it seem as if R5 and R1 are 10k but in your Schematic it is 1M and 20k.... so to make that clear: the schematic in the discribtion works like a charm (it produces around 73Hz) but the cirquit as shown in the video doesn't work.
    for clarification:
    I used a stableized, clean +/-4.7VDC power supply, an OPA2134 OpAmp and an NTE 312 JFET because those where the parts I had at home. I doubt however, that the diode was needed because of the difference in parts... I would be thankful for clarification

  • @ke9tv
    @ke9tv 11 หลายเดือนก่อน

    Heh. No classic incandescent lamp for the amplitude regulation? :) Nice explanation of the Wien bridge (if a bit hand-wavey - but that's perfect for beginners!)
    I think I'll skip over this step and go to a MFOS-style exponential VCCS. Only use a Pt-RTD instead of the old-style thermistor, they're getting hard to find and of dodgy quality while the RTD's are getting cheap.

  • @sixteenlevel
    @sixteenlevel 11 หลายเดือนก่อน

    Could a guitar trigger this, to add some bottom end to it... if yes, how?

  • @sebastian19745
    @sebastian19745 2 ปีที่แล้ว +2

    Where did you hide the arduino? how many bits is the resolution of the sine wave?
    Just kidding. Man, I am glad that I found your channel, a pure electronics channel were you explain so beautiful the concepts of basic electronics.Sadly, many forgot that old school circuits and program everything on a microcontroller.

    • @TheAudioPhool
      @TheAudioPhool  2 ปีที่แล้ว +1

      I'm very glad to hear you're enjoying the channel!
      I do agree that there is something to be had from the challenge of designing analog electronics. :) Glad to have you aboard!

    • @arvetemecha
      @arvetemecha ปีที่แล้ว

      Hello, I agree, this is such a nice channel, great content! I'm very fond of analog designs and tricks, even if the digital world pays my bills, I always go back to the "analog" parts of The Art of Electronics to have fun.

  • @dulcemariapenadediaz2820
    @dulcemariapenadediaz2820 2 ปีที่แล้ว +2

    Thanks You very much. I like your chanel because I understand better than the university class.great chanel.what it's the name of the app used for you?

    • @TheAudioPhool
      @TheAudioPhool  2 ปีที่แล้ว

      That's very kind of you to say!
      The app used for what specifically?

  • @Temu69recordsdotcom
    @Temu69recordsdotcom 2 ปีที่แล้ว +3

    class is in session

    • @TheAudioPhool
      @TheAudioPhool  2 ปีที่แล้ว +1

      Sure is! Enjoy! 😁

    • @Temu69recordsdotcom
      @Temu69recordsdotcom 2 ปีที่แล้ว +3

      @@TheAudioPhool but for real tho, this is the only channel on TH-cam I stop whatever I'm doing and pay attention thru the entire video. Incredibly engaging as a presenter and teacher, keep it up!!!

    • @TheAudioPhool
      @TheAudioPhool  2 ปีที่แล้ว +2

      @@Temu69recordsdotcom That is so kind! I'm really glad you're enjoying the videos :) Thanks for watching!

  • @sabamacx
    @sabamacx ปีที่แล้ว

    I understand why this circuit oscillates, but I don't understand why it generates a sine waveform, and not a cosh or sinc or parabolic periodic function. Could you explain or derive why it's a sine wave?

    • @TheAudioPhool
      @TheAudioPhool  ปีที่แล้ว +2

      I think the simplest way to think about why the output would be a sine wave is to think of the oscillator as a very tight band pass filter with a unity gain at the oscillating frequency. In less jargony terms, the oscillator essentially mantains a gain of 1 at a specific frequency and a gain of 0 elsewhere. That specific frequency is a sine wave by definition.
      We know from fourier that sound is made up of an infinite sum of discrete frequencies, and that each frequency is represented by a sine wave of a certain amplitude and phase. We are just highlighting one of those frequencies, which leaves us with just one sine wave! :)

  • @fragnet7673
    @fragnet7673 25 วันที่ผ่านมา

    Optocouplers with cellotape. You funny

  • @terencekaye9948
    @terencekaye9948 2 ปีที่แล้ว

    Can't find the schematics ?

    • @TheAudioPhool
      @TheAudioPhool  2 ปีที่แล้ว +1

      In the description!
      drive.google.com/file/d/1khD2Ajdpu5866NRdZzonbIwHA7jOcTK4/view

    • @terencekaye9948
      @terencekaye9948 2 ปีที่แล้ว

      @@TheAudioPhool hi thank you. The description aren't showing up on my tablet for some strange reason

    • @TheAudioPhool
      @TheAudioPhool  2 ปีที่แล้ว

      @@terencekaye9948 Yeah on mobile applications the description is a bit hard to find.
      Next to the video title there's a little downward pointing arrow that you click on to reveal the description.
      Thanks for watching :)

  • @alexlindgren858
    @alexlindgren858 10 หลายเดือนก่อน

    will this work up to 600kHz?

  • @grzesiek1x
    @grzesiek1x 2 ปีที่แล้ว +1

    I was so dissappointed recently when I made a nice oscillator and on the breadboard it worked perfectly so I decieed to make a PCB and solder all circuit on the PCB and here the problems start... actually the main problem is no oscillation.

    • @arvetemecha
      @arvetemecha ปีที่แล้ว +1

      That could be caused by the small (or not so small) added resistances and capacitances in the breadboard connections. When you soldered the same components on the almost "perfect" PCB, you lost those extra random Rs and Cs that where used to tune the oscillator within its range. I had a similar experience when I was young, as I was not allowed to use my father's soldering station, I built my first small FM emitter "DIY kit" on a piece of cardboard and connected the components using a "circuitgraph" (wrapping pen). Surprisingly, it worked and my father was so impressed he printed the PCB by the book, with everything soldered nice and tidy, and the only way to have it kind of working was to touch the collector of a transistor in the oscillator part of the circuit...

    • @grzesiek1x
      @grzesiek1x ปีที่แล้ว

      Exactly! The same story but it gives me a lesson also to calculate everything more acuratelly and for my own so I will always know what it is going on..

  • @boblewis5558
    @boblewis5558 2 ปีที่แล้ว +1

    Just a point on pronunciation ... It's actually a "veen" not "vine" oscillator from the German (Austrian) Wien meaning Vienna! 🤭

    • @TheAudioPhool
      @TheAudioPhool  2 ปีที่แล้ว +2

      Typical Englishman!
      I'll do better next time 😬

    • @boblewis5558
      @boblewis5558 2 ปีที่แล้ว

      @@TheAudioPhool wrong again ... I'm not English! And please don't insult people or their language.

    • @TheAudioPhool
      @TheAudioPhool  2 ปีที่แล้ว +3

      @@boblewis5558 i meant me!!

  • @SuperFredAZ
    @SuperFredAZ 2 ปีที่แล้ว +1

    Wien is pronounced Veen, not Vine

  • @acmefixer1
    @acmefixer1 2 ปีที่แล้ว +1

    Please pronounce wien as ween, not wine. Thanks.

  • @noliclores2101
    @noliclores2101 ปีที่แล้ว

    👎👎👎👎👎👎👎👎👎👎👎👎👎👎👎👎👎👎👎👎👎👎👎👎👎👎👎👎👎👎👎👎👎👎👎👎