Topic: USB Soundcard based on the CM6207

[Frixxion]

A while ago I bought a Trust  SC-5500P 5.1 External Soundcard:

This is the circuit board that is inside:


As you can see the circuit board looks pretty straight forward and the raw DAC signals are very easy to find. First I desouldered all the jack's and decoupling caps. Then I shortened the board a bit, because I wanted to put the USB in on the outside of a box and some of the board was in the way (look at the pics and you'll understand).

After this is done you can find the signals as in the picture below:

The +5v can be found on either the USB-in or you can follow 5v line on the board and take it from there. My 5v is the most left green cable on the board.

Now in this threadhttp://www.photonlexicon.com/forums/showthread.php?t=4920&page=3  (post 38) you can find which channel (FL, FR, CEN, SUB, etc) is going to be RGBIXY. James also desribes how to tune all the pots on the correction amp kit.

After all this I put the correction amp kit and the soundcard in a neat aluminium box:





I have not yet tested it with my scanners, but have tested it thoroughly on several scopes. It works fine, but the only problem is that the images are not very stable yet. But it might be that this won't be visible when scanning, but I'd have to try it out. The testing is going to be a problem at the moment since I have broken my ankle this weekend and I am not able to walk for the next few weeks  . If anyone has questions or tips on how to improve this thread please say so!

,Jordy

[BlinkenLights]

sweet setup... James will like it im sure

[James]

Jordy !!!

First let me say you made a beautiful box.

But I also must say OH! I'm so sorry you broke your ankle! Don't get me started! I have two fake hips and my right ankle is no good anymore. My tibia, talus and calcaneus are all pinned and screwed together into one mess. I really hope you mend well. Keep your weight off of it until it heels!

Now for the box...

Sweeeeeet!

What is the problem with the output?

Can you take pictures of the scope?

James. 

[Frixxion]

Hi all,

Srry for the long radio silence but last weeks haven't been going too well for me... Friday I had surgery and they put 7 screws and 1 plate in my ankle so that wasn't a nice experience. Right now I feel alot better and the pain in my ankle has gone  .

But now the fun stuff. I have hooked the DAC up to my DT's and the problem is now very visible. When I project anything the scan angle varies from time to time.

So, it pops from (for example) 6 deg to 7 deg about twice every second. But the image looks extremely clear and lines and stuff look very nice! The same thing is visible on my scope so the problem isn't in my scanners.

I'll try to shoot a video tonight and post it up here and I hope you can help me

Jordy

[drlava]

well I just got a few of these in and saw the same thing.  It's a design flaw in the audio card!  Note that the first CM106 usb card that I tested with had a secondary low voltage regulator for the analog side of the sound card chip and its output was rock solid.  With the new L-shaped board, and probably your board, they have left this regulator out!  This regulator is important for eliminating the noise and fluctuations from the computer power supply due to varying loads.  It is fixable, basically you need a 4 or 5V post regulator to feed the analog section of the sound card chip.  It could  be driven from the correction amp boost circuit, and simply use a lm7805.

[BlinkenLights]

can you draw that up?

[drlava]

I'll test it out and if it works, sure.

[James]

BTW How are you getting all of your color channels out of the box? Is that an XLR jack with 3 pins or some sort of multi-pin DIN?

I'm sending you all the good vibes I can for you ankle.....

I REALLY feel for you man!

Get well soon!

James. 

[drlava]

allright, the 5V reg mod works, for audio dacs that don't have a separate analog regulator.  just connect the Vin to the +9V on the amp board, gnd to analog gnd on the sound card, and +5V to the AVDD1 pin on the chip (for the L-shaped boards, solder it to the side of the diode with the white ring).  For yours, frixxion, I don't see a diode so you'll have to trace where pin 37 of that chip goes.  it's the 7th one from the top right in your photos.

[Frixxion]

Ok thank you for helping me with this! I can't make a video atm because my red diode has given up on me.... (again...) but I'll see if your solution will work for me

And btw james I don't use XLR, but it is a ethernet socket from Neutrik . So I have 8 pins :D

[Frixxion]

O yeah and thanks for the ankle vibes very much appreciated . But really I should stop visiting these laser forums, they make me wanna buy MORE laserstuff, but with my ankle, my cashflow is really low. So no more laserbuying until I can get back to work and earn some money 

[James]

My suggestion all the way around would be to take it slow and easy. Work with what you can get your hands on. Take the time to get to know everything about what you have now before you spend a lot of money on something that is just a more powerful version of what you already have. Good galvos are probably a decent investment, as they will serve your needs well for just about any combination of colors or power levels.

LaserBoy is free! The time it takes to learn how to use it is priceless!

James. 

[James]

And btw james I don't use XLR, but it is a ethernet socket from Neutrik . So I have 8 pins :D

OK. Cool.

Are you going to use shielded cable with a grounded shield?

James. 

[BlinkenLights]

you guys are skating on thin ice here with all this accurate technical discussion...

[Frixxion]

Hi James,

I already have everything figured out  but I do not have the funds right now to buy anymore stuff since I'm not able to go to work right now. So I have to try to keep as much money in my pocket as I can since I still have to save up for my party holiday  . But I have already bought a set of DT-40's so I have those already. I even have the aluminium base plate and all the combining optics . I'm planning on using a 150 mw green module, 2x200mw red DVD burner diodes and 1 or 2 PHR-800 blu ray diodes. I'm not really aiming for a perfect white balance or perfect colours. I just want to build a nice projector for now and I might upgrade those blurays to a nice decent blue laser. But I just don't have any funds for it right now . So I'll probably wait until after summer vacation when I can walk and stuff..... life sux...

I haven't really thought about using which cable yet, but is there so much signal interference when not using a shielded cable?

,Jordy