Topic: 8 Channel USB sound device for LaserBoy

[James]

The Sweex appears to be the same as the USBGEAR 8 channel USB thing.

Nice!

James. 

[Frixxion]

hmmm, is that a good or a bad thing :S because I read that it leaves some of the colors on and stuf :S and I really don't want that to happen!

[James]

Keep in mind, it is just the DAC! There are some other electronics that need to be developed in order to make this a more intelligent laser projection control system.

BTW there are a few good choices out there for 8 channel PCI sound cards too.

James. 

[Frixxion]

Never mind, I just mail ordered a trust 5.1 USB sound card and got it in today. Immediatly opened it up and it looked extremely simple . I could post a picture if you like?

[James]

Pictues!

Yes please!

Someone posted a pic of a 6 channel "blue box" that he just got and the card inside was different than the original ones that I and drlava worked with. The new one appears to use the same chip as the 8 channel device that is the object of this thread.

http://www.photonlexicon.com/forums/showthread.php?t=6940

The first chip was a CM-106L.

The newer one is a CM-6206.

They are both 8 channel DACs with USB smarts and Dolby 7.1 capability.

James. 

[Frixxion]

Ok, here it is:


It looks pretty straight forward to me where to get the signals from... Also, the IC is a CM6207, is that a good or a bad thing (A)?



BTW I have already boxed the soundcard, but I'm still waiting for my correction amp... Dr sent it out past monday, so it should be here any day now

[James]

What is that !!!

I think you found a whole new animal there!

I've never seen that board or heard of that chip before.

This sould be interesting!

James. 

[Frixxion]

What is that !!!

I think you found a whole new animal there!

I've never seen that board or heard of that chip before.

This sould be interesting!

James. 

Ah crap..... And I was hoping there would be tons of people with the same card so I could ask all my questions...

Oh well, I'll just wait for my correction amp to arrive and then I'll see

[James]

Ah crap..... And I was hoping there would be tons of people with the same card so I could ask all my questions...

You're a pioneer!

There are things you can measure right now that will be very important to know!

Have you found all of the direct outputs from the DAC chip?

Are they as easy to get to as to simply tack wires on the signal sides of the output decoupling caps?

When you have the card up in Windows and set to the 8 channel mode, what is the DC offset voltage that you read on the direct output of each channel of the DAC?

If you want to, we can also go over how to use LaserBoy to make waves that will tell you which wave channel comes out which DAC channel.

We can also set the levels of each channel to just below digital clipping (requires a scope).

What OS are you using?

Do you have Spider Player, WinAMP and VLC?

James. 

[Frixxion]

Ok, I've got it al finished up .

When at silence, the card (raw signal) puts out 2,2 vdc (don't remember if it is -or +). These raw signals are extremely easy to find. They are the only 6 lines that run to the (only) 6 caps on the card. Then with some reasoning it is easy to figure out where the XYRGB signals are going to come from.

So, I have hooked up my correction amp and got it all running. The board also has a very cool feature of a blinking LED when a sound is played. This LED also goes to full on when no sound is played, very handy!

Also James, this thing doesn't have an 8 channel mode, there are only 5 jacks on it, mic, line, front, rear, sub/center. So it is only made for 5.1 sound. Also, there is not really a driver provided with the box so I am forced to use the windows soundconfigurationscreen.

I'll open up a thread on PL with some pics and info on where to find the signals. I can post this on here also if you want to?

And also, what is this digital clipping? And is it required? Because I've got it all set up already, haven't hooked it up to my scanners yet because I first want to test it on my uncle scope . I'll post some pics of the results of the scoping next week or so, because I'm going to my uncle on sunday .

Btw, I absolutely hate winamp so I won't be using that , VLC looks easy and I might try Spider Player, but I prefer to use a proper laser program, so I might look at buying HE-Laserscan

Jordy

[James]

Of course I want you to post pictures and stuff here!

Digital clipping is what happens when the sound card driver multiplies the numerical data (obviously on the digital side) by some number greater than 1 to boost the output before it goes into the DAC. This works OK for digital information that doesn't come too close to the absolute maximum and minimum values that can be stored in a 16-bit signed integer, but if you KNOW you have signals that hit the extreems, they will be clipped. Meaning, the tops and bottoms of the waves will get chopped off. Your full-scan-sized circles will have flat sides and your color modulation will lose variation at the top end.

VLC might put your wave channels in a weird order.

So this USB thing came with no driver at all?

That's weird!

Could you please post a link to the exact device that you bought?

James. 

[BlinkenLights]

what are the VEN and DEV for that device

[Frixxion]

Happy eastern everyone!

Ok, so I just checked my DAC out on my uncle's scope and found out that it was working fabulous! Only one downside, the 5v from the USB was all over the place  (4,940 - 5) . So the scope images weren't still, they where moving . But still the Ilda pattern showed up nicely . I did make some pictures, but I forgot to take my camera cable with me, so I'll post them soon .

Ven and Dev means Vendor and Device I assume? If so  Vendor is Trust and it is the SC-5500P 5.1 External Soundcard. It did arrive with a driver disc, but nothing fancy, the driver is only to make it work if windows doesn't have a built-in driver for it.

My uncle has a very stable 5v PSU, so we're going to see if that improves things

[James]

Sounds good!

I've seen USB voltages below +5 lots of times; more often than not.

I've never seen a USB voltage that changed a lot over time.

One of the easiest ways to get around this is to get a powered USB hub.

James. 

[BlinkenLights]

Install the driver that came on the disk.. Windows drivers suck and the mfg driver often comes with a nice control pannel