Record .ILD show help

So lets say I have a few scanners and just one dac. Is there anyway I can send a show from the dac to an external recorder and then just play that show off the recorder looping all-night?


Something like this DMX version but for Lasers and the .ILD format??
ELATION DMX recorder DR-512 - eBay (item 290322742512 end time Jul-07-09 14:05:16 PDT)

I can't see any reason why, if you designed a small 6-channel amplifier, you couldn't just split the signal from one DAC to multiple scanners.. It would be a somewhat complex undertaking, since you need six channels minimum per amp per scanner, but it could be done nonetheless.

You could also build a soundcard DAC for each scanner, use laserboy to convert your shows to .wav files, and then play the files on a pc connected to each scanner. The main drawback I would see with this is that you'll need a computer and DAC for each scanner.

I've mulled over this myself for some time now, but none of the options I've considered hav been very practical. DMX works so much differently than ILDA DACs and I'm unaware of any ILDA device that would do what that device does.

The idea of splitting the cable would work EXCEPT the scanners I want to run are 1, 2, and 3 color channels so I would have pieces of projection missing if I were to do it like this

why dont you know up a one 25pin in, to 3 25pin out.

that way you can connect 3 scanners to one dac??

I don't know how much processor you need to run each setup. Could a Netbook run the required software? They are so small and inexpensive @ $300.



Jon

andy_con said:

why dont you know up a one 25pin in, to 3 25pin out.

that way you can connect 3 scanners to one dac??

Click to expand...

if the scanners have ILDA in and out isnt this the same thing.....the problem comes when one laser is argon 488nm, the second is RGY and the third is RGB....I would drop color channels if i made that cable..like my argon would be missing 2 chanels per frame and the RGY would be missing one color. They would make incomplete frames.



@k1kb0t- My full rig for lighting +visuals uses 3 pc's already so I could have 3 dacs but this is something I relay don't want to do b/c 1 PC is running Light Jockey, PC#2 is running Resolume (VJ) and the third is already running another laser

indeed it would. the only proper way is 3 dacs.

or to run the setup i said but using single colour on each projector.

andy_con said:

indeed it would. the only proper way is 3 dacs.

or to run the setup i said but using single colour on each projector.

Click to expand...

Is there anything that i could do to the cable at the projectors end, like combine the r,g and b pins, so no matter what channel was on it would make all channels turn on? or am I not making any sense now :thanks:

By my reckoning, you couldn't even run 3 monochrome scanners by splitting a DB-25 into three. The signal loss would be too great since each signal would be cut down to 1/3 the original amplitude.. That's why an amp of some sort would be necessary for each scanner.

ElektroFreak said:

By my reckoning, you couldn't even run 3 monochrome scanners by splitting a DB-25 into three. The signal loss would be too great since each signal would be cut down to 1/3 the original amplitude.. That's why an amp of some sort would be necessary for each scanner.

Click to expand...

100% TRUE, the 5v modulation signal would be destroyed without an amp

I've been spending all this time dreading the prospect of building a six-channel amp, when the work has already been done for us by the great drlava. I'm almost certain that mounting a soundcard DAC correction amp in each scanner would do the trick.. and at a nice price as well. You'd still be limited to scanners of all the same type though, like all RGB, or RGY, etc.

i disagree...

i know someone who runs 6 projectors from a single fb3, he has no problems with loss.

Check out this resource. It should give you some idea of what to do.

andy_con said:

i disagree...

i know someone who runs 6 projectors from a single fb3, he has no problems with loss.

Click to expand...

That may be, but the link Jaseth posted just above this talks about utilizing a a simple op-amp circuit to boost the signals (very similar to the drlava correction amp concept..) There's a possibility that the fb3 might have the capability of driving more than one scanner built in or it might output a more powerful signal, although I don't know as I don't own one. It's also possible your friend is using some form of small amplifier in each scanner. Any time you split a signal, you get losses depending on how many times you split. That's just a fact of electricity. Whether or not it would be enough to lower your scan angle or mess with modulation, I don't know for sure but I imagine it would depend on the DAC. TTL modulation doesn't necessarily require 5V, but analog does so an analog system would be much more susceptible to these losses. I would still recommend at least being prepared to use some form of amplifier to boost your signals..

hes not using any amplifier.

ive have 50metres of cable then split the signal to run two scanner again no loss

^Your losses may not be high enough to be noticeable.. I guarantee they're there, though. If there's no signal boosting circuitry, then there are losses when you split a signal. It's the laws of physics that dictates this, not me..

An example of this is an audio system (which works just like a galvo amp, even at the same frequencies). Let's say it's a stereo system with only two speaker outputs. If you attach only two speakers to the system, then each speaker will get the full output from each amp output. If you split each channel off to two speakers (for a total of four) each speaker will only receive a portion of its original signal. In an audio system, you can counter these effects (to a certain degree) by using speakers with a lower impedance value, but even then each speaker is not getting the full input signal.

The bottom line is that the output from the DAC is only so powerful. This power gets distributed across the entire network of conductive material that the outputs may be attached to. Unless there is a source of more power somewhere, as the network increases in size the more the power decreases at any single point on the network. Also, the number of connectors and wire length play into this to a large degree, although how much exactly is determined by the frequencies involved.

With 50m of cable, you may even be getting a little loss from the cable length. What I think is the case is that you are only splitting once off of the original outputs. Most likely this is not causing enough of a loss for you to notice, but if you were to connect more scanners and split more and more off the same source, the more you would notice the losses. You can't just keep splitting a signal over and over and over and expect it to remain at the same power. It's just not possible. Since the connection between the DAC output and the galvo amp input isn't really impedance dependent (in contrast to the speaker outputs I mentioned above), the losses aren't really as large as I previously stated so splitting only two or three times might work out.. Still I say to be prepared to use an amp, especially if you're trying to split many different ways. Not only will it overcome any of these issues, the drlava correction amp provides pots to tweak each channel for maximum signal quality. If you were to build an amp, most likely you'd end up incorporating a method of adjustment into it as well.