CYGN-B

[laserist]

Wow those are really ugly. One technique I used was to pump up the gain like 30 db (or more) and then clip it back down to move things back near a bipolar square wave.

[Greg]

Here's an analysis of an ADAT show that had no trouble yielding quality data.


length of audio segment of data for Flashback80s = 23:36


data frames collected = 59732


so
23:36 = 1416 seconds


and
1416 seconds x 40 fps = 56,640


which shows more frames collected than maximum possible if the data is an accurate 40 fps.


conclusion: The poor signal is from The Doors tape. Which is too bad, but some other shows are fine.

[Greg]

Problem solved! Full Doors data recovered. Following line of code was all that was needed:

// reject a range of values
if ((aByte < -1) || (aByte > 1))

[Greg]

Here is an excerpt to make scholarly points about laser shows.

https://www.youtube.com/watch?v=JRTmLngpfos

[lasermaster1977]

Here is an excerpt to make scholarly points about laser shows.

https://www.youtube.com/watch?v=JRTmLngpfos

And I think there are many scholarly examples of good laser show points in this excerpt. Nice work.

[Greg]

Ron correctly observed a few posts ago that I haven't proven the KQO works in the 4 channel system yet. This video does that. https://www.youtube.com/watch?v=r09_2HxrQo4

Missing is the effect where it looks like there is a sinusoid imposed on the amplitude of the spiral on the way down. I'm not sure if that would be the effect of the Burr Brown chip shaping the spiral ramp, or if that is something else.

I'm posing this before I look again at the schematics, but I'm wondering, did the PDM signal sometimes suppress the KQO reset? Or was the KQO always "keyed" by a free running on board 555?

[ronhip]

In that Dark Side number we used swept diamond spirals. My memory of most of our choreography isn't the best (I haven't done a show for 25 years!). However, since I performed Dark Side more than 3000 times, by my estimation, THAT show's choreography remains a bit clearer. I think I performed that album WAY more than the group ever performed it! And I STILL love that album!

Your KQO's look perfect!

Ron

Ron correctly observed a few posts ago that I haven't proven the KQO works in the 4 channel system yet. This video does that. https://www.youtube.com/watch?v=r09_2HxrQo4

Missing is the effect where it looks like there is a sinusoid imposed on the amplitude of the spiral on the way down. I'm not sure if that would be the effect of the Burr Brown chip shaping the spiral ramp, or if that is something else.

I'm posing this before I look again at the schematics, but I'm wondering, did the PDM signal sometimes suppress the KQO reset? Or was the KQO always "keyed" by a free running on board 555?

[laserist]

KQO was free running.