PT-30K scanner troubles

[Theoneinformant]

So I'm relatively sure that we've met. I worked with Karl at the laserdome. I'm pretty sure you where there to assist us in getting our new projectors up and running with digisynth. Summer 2006 timeframe.

[buffo]

if playing back from an audio software automatically mixing a track or two of multichannel into the wrong channels, you can get some oddities there.

Thinking the same think, Chuck. To me when he said the test pattern looked "tilted", that screamed cross-talk between x and y signals to me. (I've run into that so many damned times due to shitty cabling inside projectors - grrr!)

So that would be one thing I'd check for - ensure there's no cross-talk between the X and Y. Agree it's hard to imagine it being a wiring issue since you're using a stanwax ILDA break-out board, but the cross-talk could be happening at the Alesis board.

If you have an oscilloscope that supports X/Y mode, I'd check the signals on the output of the Alesis first and verify that they look correct.

So I'm relatively sure that we've met. I worked with Karl at the laserdome. I'm pretty sure you where there to assist us in getting our new projectors up and running with digisynth. Summer 2006 timeframe.

Considering that Laserchuck is, in fact, Chuck Rau, I'd say you're right! Chuck and Matt are absolutely the guys behind Digisynth. (Haven't heard from Mr. Polak in ages though... Wonder what he's up to these days?)

Adam

[Theoneinformant]

Ok, so after finally getting some test equipment I have figured out what the problem has been! It was a device setting deep in windows that was blending the outgoing channels... That explains why I was getting some parts of the test pattern. Now I just need to fine tune the scanner amps. I got color and blanking up as well.... but somehow in the process killed my red diode . Now I just need to figure out why the image flickers alot. LFI says 30kpps output, but it seems slow, at 10* I should be able to get 30k, I'm thinking its just tuning at this point.

[buffo]

It was a device setting deep in windows that was blending the outgoing channels.

Interesting. Sounds like a driver issue.?. Normally the USB Streamer defaults to discrete output on all channels, but I can see how things could be mixed together if Windows tried to use it like a standard stereo output device.

And yeah, mixing between channels is exactly what it sounded like to me, although admittedly I assumed it was in the wiring and not coming straight from the source like that. Glad you got it sorted though.

somehow in the process killed my red diode

D'oh! Might want to consider Lasorbs, at least for the reds. Granted, they won't do anything to help you in a case of back-reflection, but they definitely eliminate static as a source of premature diode death. Cheap insurance...

Now I just need to figure out why the image flickers alot. LFI says 30kpps output, but it seems slow, at 10* I should be able to get 30k, I'm thinking its just tuning at this point.

If your tuning is off, you'd see it in the ILDA test pattern. (Circle too small and not touching inner square, or worse not a circle at all but more of an elipse.) However, if the test pattern looks even remotely normal and you still have lots of flicker, then it isn't a tuning issue. Visible flicker on normal images means you are not actually outputting points at 30Kpps.

Put another way, your tuning needs to be *way* off (like, terrible, worst-case tuning) before it will be bad enough to cause the image to flicker. If you are seeing flicker on a simple image that should otherwise display normally, then somehow your point speed is not correct. (Note that the ILDA test pattern is a rather demanding image and will normally display some visible flicker even at 30Kpps. But something like the LaserMedia test pattern should be rock-solid stable at that speed.)

Adam