Electronic production of musical notes

Discussion in 'The Projects Forum' started by barried, Jun 27, 2014.

  1. barried

    Thread Starter New Member

    Apr 20, 2013
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    G'day folks

    I'm looking for some ideas for what ought to be a fairly simple project. I am involved in making music in an amateur way and normally I play a 12 string guitar. I've been asked to become involved in some acappella work and I'm one of those people who has no idea what key he's singing in without a guitar to guide me. Once started I'm OK, but the start is the problem. So I need to produce a little gadget which will give out one of 4 notes, A 440Hz, D 146.8Hz, G 196Hz, and C 261.6Hz. I have a decent frequency counter and a DSO so aligning a circuit won't be a problem, plus of course I have an electronic tuner for the guitar that I can compare notes to.

    Any ideas will be gratefully received.

    Cheers

    Barrie Davis
     
  2. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    Frequencies of that precision will require use of a microprocessor to generate them. Do you have programming and pcb-making facilities?
    What frequencies does your tuner produce (you can tell I'm not a musician :))?
     
  3. bance

    Member

    Aug 11, 2012
    315
    34
    You could use a voltage controlled oscillator (VCO), something like a 8038. with four buttons each providing the correct voltage for your required frequency. You'll need to buffer /amplify the output to correctly drive your load (speaker?)

    HTH Steve.
     
  4. DickCappels

    Moderator

    Aug 21, 2008
    2,658
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    A very simple approach would be to use an oscillator such as the NE555/LMC555 etc. in the astable configuration.


    [​IMG][​IMG]
    Above is from Bill Marsden's discussion of the NE555 on this forum
    http://forum.allaboutcircuits.com/showthread.php?t=74036

    You can then have four independent pots for R2, one for each note, switching among the four selections with a four position switch. The output is on pin three. What might bother you is that rectangular pulse out of pin 3 is rich in harmonics and that the spectral distribution is different for each note (because the duty cycle would change). Note: Couple pin 3 to your speaker through a large capacitor with the+ end connected to pin 3 and the - end connected to the speaker.

    Of course you can also use this technique with many other kinds of RC oscillator.http://bit.ly/1pozJuR



    [​IMG]
     
  5. DickCappels

    Moderator

    Aug 21, 2008
    2,658
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    A very simple approach would be to use an oscillator such as the NE555/LMC555 etc. in the astable configuration.

    Can't get the image to show up here, so please click to see this image:
    [​IMG]

    Above is from Bill Marsden's discussion of the NE555 on this forum
    http://forum.allaboutcircuits.com/showthread.php?t=74036

    You can then have four independent pots for R2, one for each note, switching among the four selections with a four position switch. The output is on pin three. What might bother you is that rectangular pulse out of pin 3 is rich in harmonics and that the spectral distribution is different for each note (because the duty cycle would change). Note: Couple pin 3 to your speaker through a large capacitor with the+ end connected to pin 3 and the - end connected to the speaker.

    Of course you can also use this technique with many other kinds of RC oscillator.http://bit.ly/1pozJuR



    [​IMG]
     
    Last edited by a moderator: Jun 27, 2014
  6. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    I like the idea of 555 and similar oscillators, but If I were a musician I think I'd want greater frequency stability than a simple VCO or RC oscillator is likely to provide :(.

    Edit: Do you want a sine-wave output or could you tolerate a square-wave or triangle-wave (with all their harmonics)?
     
  7. Kermit2

    AAC Fanatic!

    Feb 5, 2010
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  8. KJ6EAD

    Senior Member

    Apr 30, 2011
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    What you're describing is an electronic pitch pipe. They're commercially available. Here"s one:

    http://pockettones.com/
     
  9. Dodgydave

    Distinguished Member

    Jun 22, 2012
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    what about a ready made chromatic scale generator Ebay
     
  10. joeyd999

    AAC Fanatic!

    Jun 6, 2011
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    Iphone or android. There's an app for that...
     
    wayneh likes this.
  11. barried

    Thread Starter New Member

    Apr 20, 2013
    4
    0
    G'day folks

    Thanks very much for all the helpful suggestions. I wasn't aware of the devices available, although I did search Google originally. Obviously I didn't use the right description. I have placed an order for an electronic pitch pipe from JustGottaSing which is quite inexpensive, although of course shipping to Australia doubles the price.

    When time permits in amongst the 20 or 30 projects I have on the go I will experiment with the 555. Because the quality of the sound is unimportant, only the pitch matters, it seems like that would do the job.

    Thanks once again.

    Barrie Davis
     
  12. MrChips

    Moderator

    Oct 2, 2009
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    How about one of these:

    [​IMG]
     
  13. wayneh

    Expert

    Sep 9, 2010
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    Maybe that will be more handy than just using a smartphone or iPod, but I'm curious why you didn't try an app first. Assuming you have a smartphone, tone generators are free and you'd already have it to try while you wait for your order to arrive. If you're on stage, you're more likely to have your phone in your pocket than your pitch pipe. Just my 2¢.
     
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