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Thread: CYGN-B

  1. #121
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    more emulator output for spotting different behavior from circuit
    Attached Thumbnails Attached Thumbnails cycloid_test_004.png  

    cycloid_test_003.png  

    cycloid_test_002.png  


  2. #122
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    I think you might be summing the AM after the gain of the primary. The gain of the primary is after the AM is summed.

    Quote Originally Posted by Greg View Post
    more emulator output for spotting different behavior from circuit
    "There are painters who transform the sun into a yellow spot, but there are others who, with the help of their art and their intelligence, transform a yellow spot into the sun." Pablo Picasso

  3. #123
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    I'm not sure I understand, if

    AM signal is some value

    and

    gain of the primary is some value

    then

    total gain is sum of two values.

    I don't see the entrance of the concept of before / after.

    Do you mean the implementation of the threshold of the primary below which no modulation occurrs is suspect?

    Or which characteristic in which photo suggests incorrect summing?

  4. #124
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    There's too much AM in your images, the AM signal was summed to the primary quadrature signal and not added after the primary gain. It doesn't matter as far as the potential images are concerned, it only matters when you try to reduce the size of a specific image, and don't want to turn two pots to match the two gains as you fade the image down - and don't have a third hand the control the intensity...

    Quote Originally Posted by Greg View Post
    I'm not sure I understand, if

    AM signal is some value

    and

    gain of the primary is some value

    then

    total gain is sum of two values.

    I don't see the entrance of the concept of before / after.

    Do you mean the implementation of the threshold of the primary below which no modulation occurrs is suspect?

    Or which characteristic in which photo suggests incorrect summing?
    "There are painters who transform the sun into a yellow spot, but there are others who, with the help of their art and their intelligence, transform a yellow spot into the sun." Pablo Picasso

  5. #125
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    Quote Originally Posted by Greg View Post
    more emulator output for spotting different behavior from circuit
    You are right, we could not vary the phase of the AM relative to the FM - but interesting! At some point you get to having too many knobs to actually perform with (which we passed WAY by on the 6b console. Still... it was performable!)

    Ron

  6. #126
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    Thanks Ron. And I now see what you mean, Brian, regarding the order of summing. Thank you for recognizing that problem, your words are worth gold. The emulator gets more like what it is trying to emulate. Notice any inaccuracies in this revised statement? How much too much AM is this?
    Attached Thumbnails Attached Thumbnails cycloid_test_005.png  


  7. #127
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    There's still too much AM gain relative to the CYGNB, but that was just an artifact of how they achieved the AM function, and the hardwired gains. Is the duty cycle of your square waves 50%?

    Quote Originally Posted by Greg View Post
    Thanks Ron. And I now see what you mean, Brian, regarding the order of summing. Thank you for recognizing that problem, your words are worth gold. The emulator gets more like what it is trying to emulate. Notice any inaccuracies in this revised statement? How much too much AM is this?
    "There are painters who transform the sun into a yellow spot, but there are others who, with the help of their art and their intelligence, transform a yellow spot into the sun." Pablo Picasso

  8. #128
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    Yes, the duty cycles of the square waves in the emulator are at 50%. This leads into something I'm finding a bit puzzling: Using square waves as modulation signals doesn't seem to produce anything I remember seeing in the shows. Any recollection how a square wave, particularly as an fm signal, would have been used to good effect?
    Attached Thumbnails Attached Thumbnails cycloid_test_006.png  


  9. #129
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    I'm beginning to doubt my memory. I'll have to dig though the wire lists to check my memory of how it worked. If you look at the console and number the channels 1 to 3 bottom to top, the #1 AM/FM signal was definitely bipolar - in fact it would drive the frequency to zero at full gain and low base frequency. #2's AM/FM signal was my favorite to use. #3's AM/FM signal created images a bit more "raw' if I recall correctly...
    Click image for larger version. 

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    This is one of my favorite Osc 2 images with full AM and FM and an odd color mod. I didn't shoot much without multiple things summed in together...


    Quote Originally Posted by Greg View Post
    Yes, the duty cycles of the square waves in the emulator are at 50%. This leads into something I'm finding a bit puzzling: Using square waves as modulation signals doesn't seem to produce anything I remember seeing in the shows. Any recollection how a square wave, particularly as an fm signal, would have been used to good effect?
    "There are painters who transform the sun into a yellow spot, but there are others who, with the help of their art and their intelligence, transform a yellow spot into the sun." Pablo Picasso

  10. #130
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    Mar 2010
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    I believe that is the first actual CYGN-B output to appear in this thread, and is truly music to my eyes. Be aware, any ye following, that is not just a pretty laser image. That is the legendary circuit itself at it's best and in the hands of one of the original masters. I notice that in this and the photos of the diamond spirals, there appears to be no yellow. Not an Ar/Kr source I guess. Guessing that that is more than one scan pair. Interesting (VERY interesting) that there are 32 points in the image. I love how each one is actually a drop across precision resistors for just that point.

    I was able to get what appears to me to be pretty close to this by setting the emulator as you described, without having to change anything. Well, I did have to offset the phase between the am and fm signals, but then, I'm not sure about that exact phase relation in the first place.

    As well, thanks, that's more great info on the characteristics of the modulation sources. I'm considering the mystery still open regarding a good use of a square wave fm signal.
    Attached Thumbnails Attached Thumbnails cycloid_test_007.png  


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