ADSR circuit on LTspice

Discussion in 'The Projects Forum' started by HX2, Nov 13, 2016.

  1. HX2

    Thread Starter New Member

    Nov 12, 2016
    2
    0
    Hello !

    I am going to build this ADSR circuit, and first I have to model it, so I chose LTspice to do so. But the problem is that it doesn't seem to work : the output only shows a discontinuity at the time where the pulse starts (instead of the envelope I expect). I attached the original circuit and my model with and without alim. I chose for the input a pulse since the input is normally a trigger, but it may be a wrong choice. Plus my opamps seem to be in saturation and I'm not quite sure whether this is normal or not...
    Since I'm not that familiar with electronics I may have made a lot of mistakes, I'm sorry, but I'd be very happy if you could help me with that.
     
  2. bertus

    Administrator

    Apr 5, 2008
    19,514
    3,975
    Hello,

    You have some points not connected:

    HX2_ADSRLTSPICE_comments.png
    Bertus
     
  3. HX2

    Thread Starter New Member

    Nov 12, 2016
    2
    0
    Hello,
    Thank you for your quick reply.
    Actually on the original circuit this part is mentioned as having a role of retrigger, so that the ADSR behaves like a LFO. I tried to connect it but it doesn't make it work anyways.
    And sorry I forgot the screenshot with the alim (and I'm not at all sure about how I put it)
     
  4. ericgibbs

    Moderator

    Jan 29, 2010
    7,685
    1,548
    hi HX2,
    Comparing the circuit diagram and the LTS sim there are many errors and omissions.
    I would suggest you redo the LTS asc circuit and repost.

    E
     
  5. ericgibbs

    Moderator

    Jan 29, 2010
    7,685
    1,548
    hi HX2,
    Look at this LTS plot and circuit.
    You will have to replace the potentiometer and OPA models with your version of the models.

    E
     
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