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Thread: CYGN-B

  1. #131
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    Actually, your comment that a frequency could be driven to zero by fm may be part of the answer. I think I remember doing that. You'd have a dot that would sit there, and then whip around once. But you would adjust a frequency and synch it to the music, and that was a lick.

  2. #132
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    You are such a laserist...

    Quote Originally Posted by Greg View Post
    Actually, your comment that a frequency could be driven to zero by fm may be part of the answer. I think I remember doing that. You'd have a dot that would sit there, and then whip around once. But you would adjust a frequency and synch it to the music, and that was a lick.
    "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. #133
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    I looked at the wire lists and the center osc's AM and FM signals are the top osc's sine output. The bottom osc's AM and FM signals are from the center osc's tsin. The top osc's AM is from bottom osc bipolar squarewave, and its FM is the bottom osc's unipolar squarewave. Sorry for the confusion.
    "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

  4. #134
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    Splendid! I wasn't sure if you were joking about "wire lists", but fortunately you weren't. Everything falls so nicely into place with that scheme. To me at least, that has a very satisfying sense of Ah yes, OBVIOUSLY that's how it would have been done. Sin, triangle, and square, as per a conventional sound synthesizer. And the unipolar square for fm looks more correct. Any comment(s) on the correctness of the AM / FM phase relations are welcome, as are suggestions regarding max modulation depths in the attached graphic. I'm not forgetting that there was a triangle primary output on the center oscillator, but I'll get to that shortly.

    This discussion appears to have set the stage for consideration of an important point you raised a while back: that the type of 555s used synced through the power supply. I have little to go on regarding the implication(s) of this characteristic.
    Attached Thumbnails Attached Thumbnails cycloid_test_008.png  


  5. #135
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    Actually that was with a krypton laser, I shot that on a Sony 850 and it sees 559nm as green. That's a single scan pair...

    Quote Originally Posted by Greg View Post
    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.
    "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

  6. #136
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    If you're trying to emulate a 555 timer in code...

    As it was explained to me (by Carl Hannigan long ago) when two 555 are close to firing at the same time the first timer to transition will trigger the second timer to fire early.

    Quote Originally Posted by Greg View Post
    Splendid! I wasn't sure if you were joking about "wire lists", but fortunately you weren't. Everything falls so nicely into place with that scheme. To me at least, that has a very satisfying sense of Ah yes, OBVIOUSLY that's how it would have been done. Sin, triangle, and square, as per a conventional sound synthesizer. And the unipolar square for fm looks more correct. Any comment(s) on the correctness of the AM / FM phase relations are welcome, as are suggestions regarding max modulation depths in the attached graphic. I'm not forgetting that there was a triangle primary output on the center oscillator, but I'll get to that shortly.

    This discussion appears to have set the stage for consideration of an important point you raised a while back: that the type of 555s used synced through the power supply. I have little to go on regarding the implication(s) of this characteristic.
    "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

  7. #137
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    Single scan pair... In which case I don't know how you did that.

    Did fm on an osc have an effect on the modulation signals provided BY that osc? For example, bottom osc is primary with am / fm by center osc. If then center osc fm depth is brought up, then top osc frequency modulates center, which in turn modulates bottom?

    In the attached emulator output, would the fm be like the image on the top, and not with the peripheral loops like on the bottom?
    Attached Thumbnails Attached Thumbnails cycloid_test_009.png  


  8. #138
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    Laser Warning

    That image is a time exposure of an image that has two nodes, but was rotating over time. (Where your example has three nodes, and stable) I was playing with the mark 6 looking for different "stuff". The mark 6 had six switches in a horizontal row over the beam tourquer knob The first three summed the CYGNA oscillators to the colormod 2 output signal, the next three selected for fm and am of colormod 1, and finally selected ramp color mod 2. (which was all most laserists ever used the color mod 2 in performance.)

    Quote Originally Posted by Greg View Post
    Single scan pair... In which case I don't know how you did that.

    Did fm on an osc have an effect on the modulation signals provided BY that osc? For example, bottom osc is primary with am / fm by center osc. If then center osc fm depth is brought up, then top osc frequency modulates center, which in turn modulates bottom?

    In the attached emulator output, would the fm be like the image on the top, and not with the peripheral loops like on the bottom?
    "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

  9. #139
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    Great info on the color mod, I was just going to ask about that. Ron and Brian, thank you immensely for continuing to share your wealth of knowledge. The emulator now resembles the original circuit more closely than prior to this most interesting discussion. So... if anyone is interested in an abstracts generator that is at this time, probably the closest available thing to a real CYGN-B, this is the place to request the code.

    A short demo of some output may be viewed here:

    https://www.youtube.com/watch?v=OWTDCTi1W6w
    Attached Thumbnails Attached Thumbnails CYGN-B_emulator_demo_02.jpg  

    CYGN-B_emulator_demo_03.jpg  


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