ILDA specs

If I remember right the brightness control is 0-5 volts, I have a Laserdoc as the DAC but I am not seeing voltages that hig, I am thinking it just may be the drop across my cable but I was also wondering is the signals from the DAC need a buffer, can you directly connect the lines to the driver boards (i.e. for the intensity ) or should I build a buffer into the projector for that? I know there is very little current but I don't want to damage my DAC as well, line drivers and buffers are easy to come by and was wondering if I should put a buffer on the receiving end? I have the brightness control on the software at full output but still only seeing about 2 volts at the driver, I don't want to load down the DAC , but it could just be the voltage drop across the cable, I made the ILDA cable my self from a printer cable just with the compatible DB25 connectors on the other end and it's all working but just not seeing the full voltage on the other end

The drivers I am using are the Simple Drive 2500 units modified per BBE's recommendations to drive lower current single mode laser diodes, I like that model driver as in the future I may convert them back to there original current ratings

Thanks

Have you tested at the DAC with no cable to see if that is the issue?
I have never had the need to do anything special. It could be a bad cable or bad DAC.

If you're only seeing 2V at the driver then something is wrong, but it's hard to say what without more info. The cable should definitely not cause any appreciable drop at any reasonable length. It's possible that the DAC actually has symmetrical differential outputs, and is putting out +2.5V/-2.5V on the modulation +/- lines, but I would be very surprised if that were the case.

Testing the DAC and cable independently would be a good place to start.

Can you give us a look at how your projector is wired up?

it's very possible his meter is too slow and he's trying to measure a modulated output.

Quote:

---

Originally Posted by aberry

If you're only seeing 2V at the driver then something is wrong, but it's hard to say what without more info. The cable should definitely not cause any appreciable drop at any reasonable length. It's possible that the DAC actually has symmetrical differential outputs, and is putting out +2.5V/-2.5V on the modulation +/- lines, but I would be very surprised if that were the case.

Testing the DAC and cable independently would be a good place to start.

Can you give us a look at how your projector is wired up?

---

Agree with Chris. You need an oscilloscope to properly check modulation signal intensity.

Even when displaying a solid circle that is completely white, the controller will still be blanking the lasers periodically. A multi-meter will not interpret a modulated (blanked) color signal properly. The only way to be sure is to check it on an oscilloscope.

I'm not saying that it's isn't a problem with the controller, or the cable, or whatever. It very well could be that the voltage is in fact too low. But the readings on the multi-meter are basically useless; until you check it on a 'scope you can't be certain what the voltage level is.

Note also that a "buffer board" won't solve the problem if you really are losing voltage down a lengthy cable. Buffers by definition take whatever they see on the input and re-create that signal on the output. Unless you also include a GAIN ADJUSTMENT stage, a buffer by itself won't amplify the signal back to the 5 volt level.

Adam

Good advice. Lacking an oscilloscope, he could just provide +5v directly to the modulation inputs of each laser to see what that does powerwise. If that does the trick, then start working backwards to isolate the problem to a controller board, cable, DAC, or software.

David

It totally slipped my mind that the modulated signal would be out of range for a DMM, when I set the gain on the driver it was with a DC signal, I will check it with my scope when I get the chance.
Thanks

Quote:

---

Originally Posted by buffo

Agree with Chris. You need an oscilloscope to properly check modulation signal intensity.

Even when displaying a solid circle that is completely white, the controller will still be blanking the lasers periodically. A multi-meter will not interpret a modulated (blanked) color signal properly. The only way to be sure is to check it on an oscilloscope.

I'm not saying that it's isn't a problem with the controller, or the cable, or whatever. It very well could be that the voltage is in fact too low. But the readings on the multi-meter are basically useless; until you check it on a 'scope you can't be certain what the voltage level is.

Note also that a "buffer board" won't solve the problem if you really are losing voltage down a lengthy cable. Buffers by definition take whatever they see on the input and re-create that signal on the output. Unless you also include a GAIN ADJUSTMENT stage, a buffer by itself won't amplify the signal back to the 5 volt level.

Adam

---

Actually an actual buffer amp is a high impedience device that will pretty much ignore the trivial amount of resistance from a long cable...

Hehe, finally someone complaining about the color signals not reaching a full 5 volts, and not accusing Pangolin of being too dumb to make hardware capable of doing that, and accusing us of completely overlooking the fact that USB is rarely a full 5 volts...

I used to love those conversations (not!). Of all of the things we got right, the single thing we overlooked is that you need 5 volts on the color signals and this would be IMPOSSIBLE with a USB device. (They'd overlook the fact that the X and Y signals did swing the full 5 volts...)

Anyway, getting back on topic, yes, using a volt meter you will NEVER see the color signals reach a full 5 volts UNLESS the driving software asserts the color signals to hold the maximum voltage. In all of our software we prevent permanently holding color signals at 5 volts for safety reasons. (And we would not use a sound board to control a laser, again for safety purposes, but that's a different story... What people do in the privacy of their own home is their business :D )

Bill

Quote:

---

Originally Posted by Pangolin

In all of our software we prevent permanently holding color signals at 5 volts for safety reasons.

Bill

---

Thanks Bill, this bit of insight is very interesting. Using Quick Show or LSX with my Chinese Magnum Lighting 1W projector color on/off transitions are quite smooth. Using a 74HCT TTL buffer to drive the colors through TL084 gain-control opamps I noticed on/off transitions are not as smooth as QS or LSX over a range of output voltage maximums (4-5v). Colors initially come on bright then dim a little almost like they are becoming over-damped in the projector electronics then settle down very quickly. This only occurs at the initial frame of an image while repeating frames are not.

Being and old laser fart "new" to ILDA based projectors and standards I'm interested in insights to this behavior.

In terms of DVM vs scope we used to say "you got to see it to believe it".

Hard to say what's the cause -- whether it is purely visual (i.e. in your mind), or the fault of that which is driving the laser, or the laser diode driver. Nothing would be surprising...

If you scope the input to the laser diode driver and it's nice and square, then you could look at laser output using a photodiode and see if that it equally as square.

But there sure are a lot of crappy laser diode drivers out there...

Quote:

---

Originally Posted by Pangolin

Hard to say what's the cause -- whether it is purely visual (i.e. in your mind), or the fault of that which is driving the laser, or the laser diode driver. Nothing would be surprising...

If you scope the input to the laser diode driver and it's nice and square, then you could look at laser output using a photodiode and see if that it equally as square.

But there sure are a lot of crappy laser diode drivers out there...

---

Thanks Bill, done that already, which leads me to know that it is the signal conditioning being presented to the projector's ILDA input connector. An the surge is measurable with a laser power meter, it's not in my mind. The initial "brightness surge" does not occur with the projector laser diode outputs when driven by an EtherDream2 or FB3QS, (and these and my outputs are perfectly square as seen on a scope), only when driven by a perfectly square, TTL derived blanking signals whose peek voltage is adjusted via a TL084 opamp to be at or below the respective diode's near max voltage. I noted these two DAC's max RGB ON voltages, having been adjusted for proper blanking with LSX and QS respectively, and my circuit is replicating these full ON voltages.

Maybe the difference is that I'm not conditioning the RGB diode blanking singles to swing between near turn-on threshold and near max. on, just 0v to near max. I don't see how this could make a difference, though, could it? I should add I'm only trying to turn each color ON or OFF where ON is near but not at full intensity.

I'll take a closer look at the EtherDream2 and FB3QS blanking signals.

Just because the laser doesn't exhibit problems when driven by QS doesn't mean it's not a crap laser!

(Similar to "Just because you're paranoid doesn't mean they're not out to get you" ;) )

Bill

Quote:

---

Originally Posted by Pangolin

Just because the laser doesn't exhibit problems when driven by QS doesn't mean it's not a crap laser!

(Similar to "Just because you're paranoid doesn't mean they're not out to get you" ;) )

Bill

---

Ok Bill, you are just forcing me to use logic to diagnose this. :)

Thor makes a series of "amplified photodiodes". You can find them here:
https://www.thorlabs.com/navigation.cfm?guide_id=2171

You connect this to the scope and then compare the driven waveform to the light coming out of the projector. (Of course you must use appropriate filters to attenuate the beam going into the detector to prevent overloading it...)

This can help you to understand the quality / crappiness of the laser...

Bill

Quote:

---

Originally Posted by Pangolin

Thor makes a series of "amplified photodiodes". You can find them here:
https://www.thorlabs.com/navigation.cfm?guide_id=2171

You connect this to the scope and then compare the driven waveform to the light coming out of the projector. (Of course you must use appropriate filters to attenuate the beam going into the detector to prevent overloading it...)

This can help you to understand the quality / crappiness of the laser...

Bill

---

Much appreciated. Thanks.

Quote:

---

Originally Posted by Pangolin

In all of our software we prevent permanently holding color signals at 5 volts for safety reasons. (And we would not use a sound board to control a laser, again for safety purposes, but that's a different story... What people do in the privacy of their own home is their business :D )

Bill

---

As a soundcard geek I'm a bit confused here, please elaborate.

Sound card DACs do not blank the signal between frames. (In fact, the very concept of "frames" is rather arbitrary, if not irrelevant, when talking about sound card DACS.) However, most commercial laser show hardware will, in fact, blank all the lasers in-between frames.

The idea is that if you have a system failure, the laser will only stay on as long as it takes to complete the frame. Then it blanks. If the next frame never arrives (due to a software crash, or any other failure, really), the laser stays off. The alternative is a risk of a single, static, full power beam being emitted from the projector when Windows inevitably crashes.

This is what Bill meant when he said he wouldn't use a sound card to drive a projector "for safety reasons".

Adam

Speaking from experience with the CM-6206 USB sound device that is a popular choice for sound card DACs, if the driver for the device is left at the default setting of stereo or headphone output, the device will set all the color channels full on! So you need to know this before you power on your laser projector. You have to open the driver applet and set it to either 6 or 8 channel operation mode. You can also edit the ini file that initializes the driver so that it will only operate in 6 or 8 channel mode, so that is no longer an issue.

Quote:

---

Originally Posted by dchammonds

As a soundcard geek I'm a bit confused here, please elaborate.

---

Sound cards are made to drive speakers. If "shit happens", nobody is going to be blinded as a result...

For example, let's say you make laser software that is driving a sound card. And lets say that Windows decides to "beep", or that some generic sound software decides to output a sound. Although Windows provides the ability to select the default sound card for "beeps", what if something goes wrong? What if the selection doesn't stick, or is forgotten??? After all, we're talking about Microsoft Windows here! In such cases, at best you get scribbles on the wall. At worst, the beam is projected into an audience area...

I can't speak for the way anybody else designs their laser controllers, but one very important role of *our* software is that it "serializes access to the hardware". It means that it prevents two pieces of laser software from accessing the same laser output controller at the same time. In fact, we've made BEYOND be a kind of arbiter. Now we don't have SDKs that directly access the hardware any more. We have BEYOND. Want to talk to the hardware? Talk to (or actually through) BEYOND! The benefit is that BEYOND is able to prevent "scribbles on the wall" by serializing such hardware access. Another benefit is that right now, people who "talk to BEYOND" are able to use any connected laser hardware (QM2000, FB3, FB4, and in the future other hardware), and so this is a hardware agnostic approach. Another benefit is that BEYOND can effectively apply additional things on top of their input -- for example, additional effects or even safety-related features such as BAM, beam-velocity monitoring, feedback and such... But enough about BEYOND... (I just mentioned this to answer the question why we don't allow direct access to our laser hardware any more...)

Another thing is that we make our laser hardware to be "fault tolerant". It means that if something goes wrong inside the box, it won't result in an unsafe exposure. For example, if the negative power supply goes away in a sound card (or interface box), good luck holding the color outputs low! (Heck, from what James wrote, good luck holding them low anyway!!!)

Anyway, there are huge differences between sound cards and the laser controllers manufactured by us (and I hope other laser companies do similar things). But what people use in the privacy of their own homes is their business. Scribbles on their walls or blinded (or at least visually annoyed) pets or family members are not our business. We do hope that people will "drive responsibly" when the sound cards are used with lasers outside the confines of homes...

Bill

I think my message was to say it's a good thing to know what you are doing.

I've never had any problem using a sound card DAC.

Nor have I ever had a problem using a modified ADAT machine.

Using DC capable digital audio streams to send signals to laser projectors is probably a lot more common than one might think.

Just about any permanent laser installation in planetariums or museums probably have some way to play shows from digital multi-track audio recordings.

Professionally programmed shows are available in multi-channel wave format.

And why on Earth would you ever point a laser projector in such a way that it could EVER scan into an audience?

Quote:

---

Originally Posted by Pangolin

Sound cards are made to drive speakers. If "shit happens", nobody is going to be blinded as a result...

For example, let's say you make laser software that is driving a sound card. And lets say that Windows decides to "beep", or that some generic sound software decides to output a sound. Although Windows provides the ability to select the default sound card for "beeps", what if something goes wrong? What if the selection doesn't stick, or is forgotten??? After all, we're talking about Microsoft Windows here! In such cases, at best you get scribbles on the wall. At worst, the beam is projected into an audience area...

I can't speak for the way anybody else designs their laser controllers, but one very important role of *our* software is that it "serializes access to the hardware". It means that it prevents two pieces of laser software from accessing the same laser output controller at the same time. In fact, we've made BEYOND be a kind of arbiter. Now we don't have SDKs that directly access the hardware any more. We have BEYOND. Want to talk to the hardware? Talk to (or actually through) BEYOND! The benefit is that BEYOND is able to prevent "scribbles on the wall" by serializing such hardware access. Another benefit is that right now, people who "talk to BEYOND" are able to use any connected laser hardware (QM2000, FB3, FB4, and in the future other hardware), and so this is a hardware agnostic approach. Another benefit is that BEYOND can effectively apply additional things on top of their input -- for example, additional effects or even safety-related features such as BAM, beam-velocity monitoring, feedback and such... But enough about BEYOND... (I just mentioned this to answer the question why we don't allow direct access to our laser hardware any more...)

Another thing is that we make our laser hardware to be "fault tolerant". It means that if something goes wrong inside the box, it won't result in an unsafe exposure. For example, if the negative power supply goes away in a sound card (or interface box), good luck holding the color outputs low! (Heck, from what James wrote, good luck holding them low anyway!!!)

Anyway, there are huge differences between sound cards and the laser controllers manufactured by us (and I hope other laser companies do similar things). But what people use in the privacy of their own homes is their business. Scribbles on their walls or blinded (or at least visually annoyed) pets or family members are not our business. We do hope that people will "drive responsibly" when the sound cards are used with lasers outside the confines of homes...

Bill

---

God I wish your controllers where cheaper I would love an FB3, my employer uses them but they are still out of my price range as I don't do any for profit shows on my own, my home made stuff is just that, made for my home.

this has been a great thread and the Laser Dock DAC is doing the best it can from USB and now I do know it is working correctly, it will never hit 5 volts as it is powered by USB and I think on my current computer is about 4.2-4.6 volts give or take.
I ended up getting my Laser Dock DAC on sale when they first came out so I bought it for half of what they cost now, too bad I can't get an FB3 for 100 bucks, that would make my year and maybe next year as well

Quote:

---

Originally Posted by Draco

God I wish your controllers where cheaper

---

I wish iPhones were cheaper but they're actually going up in price not coming down...

At least our hardware isn't going up in price ;-)

If you are only getting 4.2 to 4.6 volts on your USB, you should think about getting a powered hub. I know it's an extra item and it takes another outlet, but it might help.

I don't think the 5 volts you are supposed to see on the color channels is directly from USB voltage. There must be some kind of DC/DC converter in there because the scanners have to get both positive and negative voltage with respect to ground.

Quote:

---

Originally Posted by james

I think my message was to say it's a good thing to know what you are doing.

---

I'd say that statement applies to all things laser related, whether you are a professional or a hobbyist.

I believe your average hobbyist is likely willing to accept more risk in exchange for a lower price. Also, quite a few hobbyists have used sound card DACs and gotten good results. But you also point out that it's trivial to make a settings error in windows that will cause a sound card DAC to create a spurious output. If this happens in your living room it's probably no big deal. But if it happens at a wedding reception, that's a problem!

For this reason alone, most people would consider a sound card DAC to be inappropriate for commercial use. Bill certainly thinks so, and I happen to agree with him. If you're doing commercial shows, you can afford to do them correctly and safely. There's no reason to take a short-cut.

Quote:

---

I've never had any problem using a sound card DAC.

---

Yet you also showed how anyone could get tripped up by not changing the default settings on a popular sound card DAC. You even suggested editing the .ini file. This is something that is natural to someone who is well-versed in IT, but it's not something your average consumer would think about. More importantly, none of the commercial laser controllers I'm aware of require the end user to adjust any system settings to prevent any un-commanded laser emissions.

Like I said - there's a difference between a hobbyist messing around in his basement vs someone doing commercial shows. And Bill is looking at this from the perspective of the commercial industry.

Regarding ADAT, HD-24s, Planetarium shows, and other venues/applications that use pre-recorded multi-channel audio files, remember that these are all using dedicated playback hardware. They're not running Windows, and they're not playing the audio through an inexpensive sound card purchased for $30 either.

Quote:

---

why on Earth would you ever point a laser projector in such a way that it could EVER scan into an audience?

---

I agree that masking the aperture should be part of any show setup. But I've seen cases where this has not been done. I've also personally performed shows where I could not rely solely on the mask due to the long throw of the projector. (You always get some diffraction around the edge of the mask when the beam hits it, which lowers the resulting cut-off horizon.) I've had cases where I would lose half my vertical scan field size to this diffraction when I positioned the mask to fully clip at the 3 meter line. And even if the mask will prevent accidental audience scanning, you still have beams being displayed when you don't want them to be. That's not acceptable for professional grade equipment.

Adam

Quote:

---

I'd say that statement applies to all things laser related, whether you are a professional or a hobbyist.

---

Well shit. Now you tell me.

Hang on a minute. It's not like the sound card DAC flips the colors on full at any random time. I did not say that and this does not happen. When Windows boots up and initializes the sound card driver, if it is set to stereo or headphone out, the other channels go high. How many times does this need to happen before you figure out not to turn on your laser projector until Windows is fully booted and you have opened the sound card driver applet and made sure it is set to 6 or 8 channels? Or alternatively, you are prepared for the beam to come on when it does.

Quote:

---

Originally Posted by james

If you are only getting 4.2 to 4.6 volts on your USB, you should think about getting a powered hub. I know it's an extra item and it takes another outlet, but it might help.

I don't think the 5 volts you are supposed to see on the color channels is directly from USB voltage. There must be some kind of DC/DC converter in there because the scanners have to get both positive and negative voltage with respect to ground.

---

Yeah I think I will put it on a hub but I am satisfied that it is working correctly and I was measuring the signal voltages with a DMM instead of an Oscilloscope

Quote:

---

Originally Posted by Pangolin

Sound cards are made to drive speakers. If "shit happens", nobody is going to be blinded as a result...

For example, let's say you make laser software that is driving a sound card. And lets say that Windows decides to "beep", or that some generic sound software decides to output a sound. Although Windows provides the ability to select the default sound card for "beeps", what if something goes wrong? What if the selection doesn't stick, or is forgotten??? After all, we're talking about Microsoft Windows here! In such cases, at best you get scribbles on the wall. At worst, the beam is projected into an audience area...

Bill

---

One of the available Windows sound schemes is 'No Sounds'; also if you're using EzAudDac, you can choose what sound device to talk to so you're not stuck with the selected Windows default device. If Windows fails, or your computer fails (much more likely), it's game over no matter who's laser controller is connected.

It's also worth noting that unlike many other laser DACs, a sound card is not tethered to only Microsoft Windows. So if you are not confident of Windows' stability, you have other options.

The general concept of using multi-channel digital audio streams to control a laser projector is hardware and OS agnostic. As a matter of fact it doesn't even require a computer with an OS.

If "the industry" has told us anything, it is that laser signals fit entirely inside of the general definition of digital audio.

There might be a lot of proprietary hardware and applications out there, but at the end of the day the output of any DAC can be recorded as digital audio.

(mic dropped)

James.

Oh, I forgot the most important rule when driving a laser from a soundcard:

Stay off of Snapface or Instachat or whatever!*nyancat

https://youtu.be/UwMBhQdsvoI

What should be stressed in the world or laser entertainment (professional or personal) is safety, safety procedures and best practices. For any given situation there may be appropriate, calculated minor deviations as long as safe practices are observed. It is great to have inherent, automatic, built-in safeguards is any product, but it doesn't amount to anything if the operator is not educated in how to deal with best practices in setting up, starting up and use of laser projectors and equipment.

This forum to me has shown to be a place where valuable knowledge is shared and exchanged generously, including laser safety. The key is and has always been to seek, learn or develop a safety best practice for your given situation, one that protects you and others. We used to always have a goddamn mechanical, or better still, an electro-mechanical shutter that blocked the output aperture of any and all laser beams to be output by projection devices that defaulted to blocking the aperture whether device power was on or off, regardless whether there was subsequent high-speed blanking devices up or downstream. Only when the shuttered device's electro-mechanical aperture was energized was an output beam allowed to exit. This is old school, yes, but still a best practice.

In the news last night, a story of a man charged with a DUI who was driving a self-driving Tesla. The only way the police could stop him since he was asleep at the wheel was to pull in front of him and stop, so the self-driving car would stop. Just because safety is built-in doesn't mean it will work as needed for all situations.

You can kick around Microsoft Windows all you want. Although if your choice of DAC only works in Windows, I'm not sure how that bolsters your case. You can pick on an individual sound device if you want. But you can't denounce the general idea of using digital audio hardware to produce laser control signals.

James.

Um... Uhhhhh ..... ummm..... where's Bill?

James. :)

Quote:

---

Originally Posted by james

Um... Uhhhhh ..... ummm..... where's Bill?

James. :)

---

Dude, he's getting the Patriots ready for the next game!:cool:

Quote:

---

Originally Posted by dchammonds

If Windows fails, or your computer fails (much more likely), it's game over no matter who's laser controller is connected.

---

HEHE, the question is how the game is over. If Windows fails and you have a laser controller made by a responsible company, then the beam is blanked immediately. (FB3 has zero internal memory, and requires a constant stream of data fed to it. If data stops, FB3 blanks the beam immediately. Similar story with FB4, but it does have a tiny amount of memory...) On the other hand, it is easy to imagine a scenario that will allow sound card dacs to remain in a constant state in the event of problems.

Bill

Quote:

---

Originally Posted by james

But you can't denounce the general idea of using digital audio hardware to produce laser control signals.

James.

---

This is like saying "you can't denounce standing on a bunch of boxes to change a light bulb located on a really high ceiling". Well, it might work (and I'm not saying I've never done this), but safety-minded folks would not only denounce this, but would also just bring out a ladder!

Dude, we have laser control hardware to produce laser control signals! It's not like laser controllers don't exist! Use the right tool for the job!



Bill

Quote:

---

Originally Posted by Pangolin

HEHE, the question is how the game is over. If Windows fails and you have a laser controller made by a responsible company, then the beam is blanked immediately. (FB3 has zero internal memory, and requires a constant stream of data fed to it. If data stops, FB3 blanks the beam immediately. Similar story with FB4, but it does have a tiny amount of memory...) On the other hand, it is easy to imagine a scenario that will allow sound card dacs to remain in a constant state in the event of problems.

Bill

---

What does your controller do when the projector goes haywire?

Quote:

---

Originally Posted by Pangolin

This is like saying "you can't denounce standing on a bunch of boxes to change a light bulb located on a really high ceiling". Well, it might work (and I'm not saying I've never done this), but safety-minded folks would not only denounce this, but would also just bring out a ladder!

Dude, we have laser control hardware to produce laser control signals! It's not like laser controllers don't exist! Use the right tool for the job!



Bill

---

No it isn't. It's just a matter of using a ladder with a different name brand on it.

We've been over this before. There is a huge advantage in recognizing that laser control signals are digital audio. There is a whole world of hardware and software dedicated to digital audio. It just takes a bit of imagination to leverage its use for laser projection. And whether you like it or not, it's been going on pretty much ever since laser projection was a thing.

Quote:

---

Originally Posted by Pangolin

HEHE ..... On the other hand, it is easy to imagine a scenario that will allow sound card dacs to remain in a constant state in the event of problems.

---

Oh really? Then go ahead and image that for me. Exactly how would that happen?

If soundcard DACs would send 0V to all channels when nothing is sent to them then I think they would be as safe as anything. But, that isn't the case, at least for some of them. It's a shame and something that the soundcard manufacturers could easily fix but I don't think they expect them to be used in this manner.

Yes. That's true. Those little capacitors in series with the outputs of the DAC channels can eliminate the issues of what state the DAC is in at any given time. But it's consistent. It is a knowable situation that can be managed. And there are many different devices to choose from.

Quote:

---

Originally Posted by JohnYayas

If soundcard DACs would send 0V to all channels when nothing is sent to them then I think they would be as safe as anything.

---

Sounds like the first step in engineering a dedicated laser show controller. :rolleyes: Well, and removing the DC-filtering caps, and adding the correction amp, and so on...

Also, I should point out that there have been commercial laser show controllers (old school) that were based on sound card designs, but they were heavily modified to add the sort of safety precautions we're discussing here. And yes, those modifications would be pointless if the card were just driving someone's home speakers.

Quote:

---

It's a shame and something that the soundcard manufacturers could easily fix but I don't think they expect them to be used in this manner.

---

In fairness, the laser light show industry is tiny compared to the general market for sound cards, so I can't see why they would bother. Sure, it's an important feature for a laser controller, because you want it to fail in a safe state, but it's certainly not required for any of the more common uses for a sound card, so why spend the money adding a feature that would be useless to most of your market?

Adam

Quote:

---

Originally Posted by buffo

Sounds like the first step in engineering a dedicated laser show controller. :rolleyes: Well, and removing the DC-filtering caps, and adding the correction amp, and so on...

Also, I should point out that there have been commercial laser show controllers (old school) that were based on sound card designs, but they were heavily modified to add the sort of safety precautions we're discussing here. And yes, those modifications would be pointless if the card were just driving someone's home speakers.



In fairness, the laser light show industry is tiny compared to the general market for sound cards, so I can't see why they would bother. Sure, it's an important feature for a laser controller, because you want it to fail in a safe state, but it's certainly not required for any of the more common uses for a sound card, so why spend the money adding a feature that would be useless to most of your market?

Adam

---

Well, of course, those are good points. I wasn't claiming that soundcard DAC manufacturers should make a change for laser show use, I'm just saying that it is a shame that they aren't already sending them to 0V as a general practice, because then all would be fine. The firmware change to do that would be cost nothing (when factored into the life of the product). In actuality, the filter caps will cause the output to be 0V when there is no signal so they already ARE paying to do that with every unit. It's just that the caps get removed when modding them.

The real shame is that laser controller DACs are so expensive and every one of them has their own oddball API. I can't wait for IDN to pick up and end this nonsense.

Quote:

---

Originally Posted by JohnYayas

The real shame is that laser controller DACs are so expensive and every one of them has their own oddball API. I can't wait for IDN to pick up and end this nonsense.

---

We used IDN at the 2018 ILDA conference in Montreal. No db25's running to lasers. The ability to dynamically route groups of dacs to groups of projectors without having to do any cable swapping made switching disparate laser sources quick and seamless. It was great, but I would love to see more vendors supporting it natively. Seeing a table full of network dacs plugged into IDN stagemates and then into another network was silly.

Attachment 54811

If you want my IDN Modules, You can peel them from from my cold dead hands.
Love that hardware.

Steve

The ability to reroute IDN signals as well as carry DMX signals is pretty cool. I still have some hesitations at the moment though. As I said at ILDA, I think its fine to integrate IDN directly into DACs as long as the receiving Stagemate in the projector can run alongside a legacy ILDA input. (I currently don't want to put DACs directly in my projectors as I am currently required to reroute signals between projectors externally due to software limitations.)

In addition, Stagemates also need to come WAY down in price as the transmitter and the receiver are currently 350 Euros and 300 Euros respectively. Obviously the cost is lower if you integrate IDN into the DACs themselves and then that DAC into the projector directly. I'm sure there are some advantages to the approach various DAC manufacturers have taken to run their signaling over Ethernet lines that may drive end-consumers to want to choose those alternate protocol(s). Personally, I'm a fan of both (good) standards and control flexibility.

-David

Quote:

---

Originally Posted by dkumpula

The ability to reroute IDN signals as well as carry DMX signals is pretty cool. I still have some hesitations at the moment though. As I said at ILDA, I think its fine to integrate IDN directly into DACs as long as the receiving Stagemate in the projector can run alongside a legacy ILDA input. (I currently don't want to put DACs directly in my projectors as I am currently required to reroute signals between projectors externally due to software limitations.)

In addition, Stagemates also need to come WAY down in price as the transmitter and the receiver are currently 350 Euros and 300 Euros respectively. Obviously the cost is lower if you integrate IDN into the DACs themselves and then that DAC into the projector directly. I'm sure there are some advantages to the approach various DAC manufacturers have taken to run their signaling over Ethernet lines that may drive end-consumers to want to choose those alternate protocol(s). Personally, I'm a fan of both (good) standards and control flexibility.

-David

---

totally agreed. regardless of whatever dac is installed in a projector, i hate to see projectors that doesn't support an external ilda signal.

hardware costs for stagements could be drastically reduced by integrating support into existing dacs.

Quote:

---

Originally Posted by dkumpula

The ability to reroute IDN signals as well as carry DMX signals is pretty cool. I still have some hesitations at the moment though. As I said at ILDA, I think its fine to integrate IDN directly into DACs as long as the receiving Stagemate in the projector can run alongside a legacy ILDA input. (I currently don't want to put DACs directly in my projectors as I am currently required to reroute signals between projectors externally due to software limitations.)

In addition, Stagemates also need to come WAY down in price as the transmitter and the receiver are currently 350 Euros and 300 Euros respectively. Obviously the cost is lower if you integrate IDN into the DACs themselves and then that DAC into the projector directly. I'm sure there are some advantages to the approach various DAC manufacturers have taken to run their signaling over Ethernet lines that may drive end-consumers to want to choose those alternate protocol(s). Personally, I'm a fan of both (good) standards and control flexibility.

-David

---

Well - StageMate ISP _is_ the/a DAC and IDN is just a protocol. Any software system can just output IDN and there are some drivers/implementations already. That way you won't have to do the additional ADC/DAC conversion (this was always thought as a compatibility solution for older - and analog - systems, that can't send IDN).

Best
--Dirk

Quote:

---

Originally Posted by swamidog

totally agreed. regardless of whatever dac is installed in a projector, i hate to see projectors that doesn't support an external ilda signal.

hardware costs for stagements could be drastically reduced by integrating support into existing dacs.

---

Jep - even better would be existing DACs could implement IDN...

Quote:

---

Originally Posted by DexLogic

Jep - even better would be existing DACs could implement IDN...

---

yes.. that's what i was trying to say. ;)