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Thread: WANTED - DAC for 15k scanner

  1. #11
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    That looks like a whole new DAC...
    Love, peace, and grease,

    allthat... aka: aaron@pangolin

  2. #12
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    Quote Originally Posted by Eliezer
    Hello, andy_con:

    I have just for Sale what you need:

    http://photonlexicon.com/forums/viewtopic.php?t=823

    Price: $490.00 include DAC and shipping cost by DHL to your home door.

    Can contact me: export@artlaser.net

    Sincerely,
    Eliezer
    i dont have $500 sadly.
    Eat Sleep Lase Repeat

  3. #13
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    Quote Originally Posted by Spec
    Quote Originally Posted by andy_con
    ignore the price for a min, is the DAC Alphalite PRO and software any good??
    Short answer: No.



    Long answer: Maybe, if you want to put more time and money into it than BILDA.

    It has potential but the design is too simplistic and lends itself to terrible output. I had to add the decoupling caps out of necessity, change the DAC's, cut the ground loop out, add external adjustment pots, and a slew of other crap but that still didn't help much... serious issues like the software-based timer are not fixable without a serious code overhaul.

    I lost the PM I sent to buffo a year or so ago... I went on for a solid 2 pages on its "limitations".

    Save your money for something better. I am expecting good things from the upcoming Pangolin "Hobbyist-o-matic" or whatever its trade-name will end up being.
    how can it be that bad??? does it not work???
    Eat Sleep Lase Repeat

  4. #14
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    The Alphalite DAC does work, yes. And you can display both beams and graphics with it. However, it is not an optimal solution. There are problems when you use the parallel port of a PC to control something that is timing-critical. This is because the data flow to the parallel port can be interrupted by any number of system events. When this happens, the beam will "freeze" in position. (This problem affects ALL parallel port DACs, not just the Alphalite.)

    Using the Alphalite, you'll see this problem manifest whenever you switch between file directories. As the computer loads up the next set of files, you'll have a static beam shooting off in a random direction for about a second or two. Then, once the files are loaded, it will start displaying the new file as if nothing happened.

    Likewise, there are system events (housekeeping tasks) that can also cause the beam to freeze momentarily. And even when the file is being displayed, there are small timing shifts in the Alphalite hardware itself that cause the image to distort slightly. (This is known as sample jitter; basically it means that some points come out earlier than they should, while others come out a little later than they should.)

    There are some modifications that you can do to improve the stability and reduce the noise in the Alphalite's output (see Spec's picture above), but there is nothing you can do about the timing problems inherent in a parallel port DAC.

    Now, how big of a deal is all this? That depends. If you're just trying to get an image, any image, displayed on your wall in your living room, then the Alphalite will do that. It may not be the best quality image, but it will display an image. It will also display beams, fans, and sine waves. It has a decent abstract generator that will create interesting lissajous patterns. It also has a text-display tool, and an auto-trace tool that works at least as well as some of the other one's I've tried. (Which is to say that none of the autotrace tools work very well.)

    In all, the Alphalite is a bare-bones product that tries to do a lot of different things, and while it doesn't do any one thing really well, it will give you a taste of what is possible with a laser and a set of galvos. It is also relatively inexpensive. Note that you will NOT be able to syncronize a show to music using the Alphalite, but you can assign ilda files to function keys and "play along" on the keyboard in real time to music that is playing from another source.

    However, once you've used the Alphalite for a while, you begin to notice that your images have annoying tails at certain points where there shouldn't be any beam visible. You notice that the lines don't always overlap perfectly on a scanned image, giving a blurry-edge effect. You'll see hot spots and "sparkles" in a scanned image as the scanners halt for the briefest of moments while drawing the image. You'll also notice that if you aren't careful with the abstract generator, you can send some signals to the scanners that can actually harm them.

    To avoid these problems, you'll need to upgrade to a better DAC. And while Pangolin products are more expensive than the Alphalite, they are also higher-quality products that will not exhibit any of the problems listed above. So it comes down to your budget, and how fussy you are about the quality of the finished product. And if you're thinking about doing shows for the public, you definitely want to upgrade to a better DAC.

    I've owned an Alphalite for a year now, and I've decided that it no longer meets my needs, which is why I'm looking to trade up. The combination of the Mamba Black software and the EasyLase USB DAC seemed to be the ideal solution up until last weekend, when we discovered that even the EasyLase USB DAC exhibits some sample jitter. Truthfully, I didn't notice it when watching a laser show that was playing, but when we brought up certain test patterns it was evident. Checking the signal with an oscilloscope proved that the problem was in the DAC. Connecting the projector to a Pangolin board solved the problem... (Score one for Pangolin!)

    The real wild card here is this new hobbyist board from Pangolin that everyone has been talking about. Given that Bill Brenner has publically stated that his new hobbyist product (which will be based on the Flashback 3 unit) is going to be released in the next few months at a price point of near $500, I'd say it would be prudent for ANYONE thinking of upgrading their DAC to wait until this product is released, and then to at least take a hard look at it before buying anything else.

    There's no question that Pangolin has always stood for quality, but until recently that quality came with a steep price that many in the hobbyist community could not afford. But if this new unit hits the $500 price point, it will be *very* competitive with other systems (including the Alphalite and the Mamba Black/Easylase combination) that are currently popular in the hobbyist market. In fact, I'll go so far as to say that at a price of $500, there really isn't *any* valid arguement to purchase *any* other product. But we'll have to wait until the unit is released to see what it can do...

    That's my opinion anyway...

    Adam

  5. #15
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    at the moment i dont have a dac, only a DMX. so buying this would be a good start into laser shows right???
    Eat Sleep Lase Repeat

  6. #16
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    Andy, if you give me a week I will send you a board for the popelscan.
    I think you will be able to get the bits for it easy enough.

    Jim

  7. #17
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    ive got the chips already, just no board.

    ive been told popelscan and this one are on the same level
    Eat Sleep Lase Repeat

  8. #18
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    That is true. The difference is that Poplescan is free (except for the cost of the parts needed to build the DAC), whereas the Alphalite system costs $350 (and used to cost $750!). Of course, the Alphalite software does a *lot* more than the Poplescan software, but if you're just trying to get your very first image up on the wall, Poplescan will do it.

    There's nothing wrong with working your way up the ladder (both in hardware and software) as you get more and more involved with this hobby. As I mentioned above, I started out with the Alphalite, and now I'm ready to move up. But if I had known about the problems with the Alphalite from the begining, I might have waited a month or two and bought something a bit nicer to start off with. That's the only lesson we're trying to pass on: sometimes it's better to start out with a little nicer unit.

    But if you are on a tight budget, or you feel that you absolutely have to start right now, then the Poplescan unit will get you up and running.

    An Alphalite unit will give you some added features, but will cost you $350.

    The Mamba Black/Easylase combination is very nice, but will cost nearly $800 and will still exhibit some sample jitter.

    Whereas the new Pangolin unit should offer at least the same functionality as Mamba (if not more) while also offering a superior output (better DAC) for around $300 less than the Mamba/Easylase combination. But you'll need to wait a couple months...

    Adam

  9. #19
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    Quote Originally Posted by Buffo
    That is true. The difference is that Poplescan is free (except for the cost of the parts needed to build the DAC), whereas the Alphalite system costs $350 (and used to cost $750!). Of course, the Alphalite software does a *lot* more than the Poplescan software, but if you're just trying to get your very first image up on the wall, Poplescan will do it.

    There's nothing wrong with working your way up the ladder (both in hardware and software) as you get more and more involved with this hobby. As I mentioned above, I started out with the Alphalite, and now I'm ready to move up. But if I had known about the problems with the Alphalite from the begining, I might have waited a month or two and bought something a bit nicer to start off with. That's the only lesson we're trying to pass on: sometimes it's better to start out with a little nicer unit.

    But if you are on a tight budget, or you feel that you absolutely have to start right now, then the Poplescan unit will get you up and running.

    An Alphalite unit will give you some added features, but will cost you $350.

    The Mamba Black/Easylase combination is very nice, but will cost nearly $800 and will still exhibit some sample jitter.

    Whereas the new Pangolin unit should offer at least the same functionality as Mamba (if not more) while also offering a superior output (better DAC) for around $300 less than the Mamba/Easylase combination. But you'll need to wait a couple months...

    Adam
    ignore the price of alphalite, i get discount. well im gona go for it, ive been trying to get a dac for 4 months now with no luck, i cant wait any longer.
    if it does not do the job i can get a refund, so should be cool.

    and thanks for passing on your experiences
    Eat Sleep Lase Repeat

  10. #20
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    I keep seeing mention of a jitter with Easylase DAC. Has anyone noticed this with LDS software? Or is it just Mamba or the DAC itself? Someone elaborate a bit here.... :?: No cluebyfour needed.....just wondering if any comparisons have been made.
    You are the only one that can make your dreams come true....and the only one that can stop them...A.M. Dietrich

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