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FrozenGate by Avery

PICS: Sound card DAC / Spaghetti problems

carmangary said:
You're missing the point. It isn't about how complex it is to build, it is about how complex it is to use. The sound cards are not opening the doors to newbies like I thought they might due to the fact that they aren't easy to build and use. In my opinion, it's easier to just save up the extra $125 or so and buy a pre-made RIYA.

What I want to see is something like a RIYA or EasyLase but without the TTL, DMX, and SD cards at a price of $99 or less. Maybe in a kit form with no case or connectors added... I think it could be done, though.
Click to expand...

I'd buy that for sure... I'm not even building this thing for me.. its for a DJ for him to have a laser show with his DJ services. I'm going to miss his Halloween 10/31 deadline because I have never done this before and I'd be more than happy to pay to get a working DAC.


anyways, I took some pics of whats going on in my Sound Card DAC and laser scanner, sorry for them being so big but if they're small no one can see anything.

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Also I have some good news, I set the sound card output to 6 channel and now when I display the test frame in Spaghetti the laser actually does a small change, it keeps projecting the demo programs from the Program board but does seem to flash around and moves the laser around very slightly like every 10 ms, it doesn't actually look anything like the ILDA test frame but at least its doing something when it is supposed to...

I'm going to try re - tunning my sound card DAC and see if that does anything. Also I'll check out that link about the projection connections and put 7 and 14 (or whatever pins it was) together on my DB25 cable, I guess I can do this by just shorting those pins on my Breakout board. Anyone know if I need to put anything into the other inputs on the Breakout board?

thanks for the help everyone.

-Kendall
 
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sounds like your DMX board isn't in ILDA passthrough mode. If it came with instructions, read up on how to set it into passthrough. Maybe someone who has used one can tell you how.
 
On your correction amp, there seem to be 3 missing capacitors around that transistor near the correction amp inputs...
 
carmangary said:
You're missing the point. It isn't about how complex it is to build, it is about how complex it is to use. The sound cards are not opening the doors to newbies like I thought they might due to the fact that they aren't easy to build and use. In my opinion, it's easier to just save up the extra $125 or so and buy a pre-made RIYA.

What I want to see is something like a RIYA or EasyLase but without the TTL, DMX, and SD cards at a price of $99 or less. Maybe in a kit form with no case or connectors added... I think it could be done, though.
Click to expand...

In terms of electronic skill, it doesn't get much easier than a sound card DAC, and aside from some very minor learning-curve issues I've never had any problems with mine. If a person is not comfortable working with electronics, or has very limited experience, then the soundcard DAC is not a good choice for them, even as easy as it is. That's an issue with the builder, though, not with the device itself. It's really not that hard to get them to work extremely well, and I have lots of raw video to back that up. I've run my system for 8 hours straight at a time without a hiccup, it works every time, and now that I have everything set up, I don't have to mess with anything. It may as well be a factory-assembled DAC. If you upgrade the DC-DC converter to one that gives +-12V, you even get the full scan angle that a commercial DAC provides.

I agree wholeheartedly that a stripped down RIYA kit would be awesome.. but that might never happen. For now, the soundcard DAC is the best, most practical DIY DAC option.
 
Riddle me this. If you give your sound card DAC to your neighbor and tell him to get it working on his computer with no instructions, how long do you think it will take for him to figure it out? Next, if you wrote down the instructions step by step for every current O/S (XP, Vista, Win7), how many pages would it take to describe the steps so that a complete novice could get it working?

Why do I ask? Because that is what you will face when you haven't used it for a year or so and try to use it again. How much pain will it take to refigure it out? And how much pain would it take to document it all, assuming you won't lose the documentation.

I'm not trying to convince people that sound card DACs are inferior in terms of performance. I just want people to be aware that if you just hold off for a few months you can probably save the money by eating smaller lunches to buy a real DAC and in the long run it will be more than worth it.

I suppose the same could be said in regards to buying Spaghetti vs a Pangolin system. But, in the long run I do hope that I get Spaghetti to be easier to use than Pangolin systems and powerful enough to do what most home-laserists are interested in.

But ultimately, my complaints against the sound card DACs are explained by the title of this thread: "Sound Card DAC / Spaghetti Problems".
 
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Really it's not too bad, even with no experience. ESPECIALLY with Spaghetti. The only thing a person needs to do once they have built and tuned that DAC (tuning will require you to install the drivers) is set Spaghetti to use the card (easy since there is a drop-down list) and adjust certain things like any inverting you might need, adjust the pitch and yaw, blanking timing, etc.. Then you just need to adjust color balance (also quite easy).. Other than that, if it's not working at that point you need to look at your wiring. A lot of the simplicity of using the sound card DAC can be attributed directly to Spaghetti IMO. It was pretty easy for me to figure out how it was supposed to go. You can't DIY anything if you're not prepared for a little more work than if you just went out and bought whatever you're trying to build.. For me, the feeling of having built and customised my own DAC interface as well as the scanner itself is quite rewarding. To each his own, though..

So, to answer your question, I don't think it would take much more than a page to scrawl out some instructions..

Personally, I think that Spaghetti and the sound card DAC are a perfect match and together make for quite a good solution.
 
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Just look at the problems he had, shorting PCBs to the case, DMX passthrough problems, they would happen even with a commercial DAC. If a low cost commercial DAC named POGO were marketed, you would get all kinds of threads like "POGO DAC / Spaghetti Problems" and for some people the POGO DAC would start getting a bad rep. Part of the problem is that the sound card DAC doesn't have a user manual, I guess that's my fault partially, and people can get confused while tuning it, but as ElectroFreak said, for most DIYers it's one of the simpler projects they have completed.
 
drlava said:
Just look at the problems he had, shorting PCBs to the case, DMX passthrough problems, they would happen even with a commercial DAC. If a low cost commercial DAC named POGO were marketed, you would get all kinds of threads like "POGO DAC / Spaghetti Problems" and for some people the POGO DAC would start getting a bad rep. Part of the problem is that the sound card DAC doesn't have a user manual, I guess that's my fault partially, and people can get confused while tuning it, but as ElectroFreak said, for most DIYers it's one of the simpler projects they have completed.
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building a phr is easier xDDDDDDDD
 
Updated the sound card DAC tutorial with a complete wiring diagram and detailed tuning instructions. They should help you work out some of these issues..
 
ElektroFreak said:
Updated the sound card DAC tutorial with a complete wiring diagram and detailed tuning instructions. They should help you work out some of these issues..
Click to expand...

Thank you for doing that. Do you have a link to this online somewhere? I would like to add it as one of my links on my website if you don't mind.
 
drlava said:
Just look at the problems he had, shorting PCBs to the case, DMX passthrough problems, they would happen even with a commercial DAC. If a low cost commercial DAC named POGO were marketed, you would get all kinds of threads like "POGO DAC / Spaghetti Problems" and for some people the POGO DAC would start getting a bad rep. Part of the problem is that the sound card DAC doesn't have a user manual, I guess that's my fault partially, and people can get confused while tuning it, but as ElectroFreak said, for most DIYers it's one of the simpler projects they have completed.
Click to expand...

I don't know. When you receive a piece of hardware in a box you usually don't question whether or not it is working like you do a bare circuit board that you wired up. I see your point, though. What would be very helpful would be to have some type of tester that would help determine if the sound card DAC is working. It could be something like speaker jacks and a multichannel wav file that you could play to see if sound is being isolated from each channel. Or maybe leds and a wav file that would turn them on one at a time or something. Just something that can let the user know it is working after they build it. Someone with an oscope wouldn't need it but oscopes aren't everyday items. Improved documentation or any documentation would also help. These would definitely eliminate some uncertainty.
 
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carmangary said:
What would be very helpful would be to have some type of tester that would help determine if the sound card DAC is working.
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I was thinking about writing a mini app that would display the ILDA test pattern and allow output voltage level adjustments. That way people wouldn't question SPaghetti, all the debugging could be done with EzAudDacTest.exe
 
drlava said:
I was thinking about writing a mini app that would display the ILDA test pattern and allow output voltage level adjustments. That way people wouldn't question SPaghetti, all the debugging could be done with EzAudDacTest.exe
Click to expand...


That would be useful. But for a simple sanity check it would be awesome to have a little application with some buttons, sliders, comboboxes, or whatever that would allow you to individually or by some combintation select 0V, -5V, or +5V on X, Y, R, G, B. Then you could easily tune it with a multimeter and verify that all signals are isolated. In fact, you could extend the app to have a wizard with several steps that guides the user through steps such as :
1) Hook multimeter to X and adjust pot 1 for 0V output and then click OK
2) ... same for other channels.
3) Hook multimeter to X and adjust pot 1 to 5V ...
etc etc

You should be able to easily whip up something like that in an evening using VB.
 
ElektroFreak said:
I don't know for sure if you need LPF membership to view it, but here's a link to the full tutorial:

http://laserpointerforums.com/groups/scanner-group/sound-card-dac-tutorial-41.html

If necessary I can put it in a thread so anyone can view it..

Please feel free to point out any errors or discrepancies.
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I don't think I will link to that since it is a forum thread but thanks for pointing me to it. If you or anyone decides to create a webpage or even just an HTML page it would make a great addition to my website and google group so feel free to contact me in the future about it if you are interested. The more that the information is spread out the better. I'll be more than happy to credit the person who created the document and also supply a link to your website if you are selling DAC boards or whatever.
 
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