USB Audio DAC mod + LaserBoy Correction Amp

[James Lehman]

Relax. Today is really Wednesday!

James.

[allthatwhichis]

Relax. Today is really Wednesday!

James.

Heh, I get to work from home on wednesdays... although we worked from home last thursday, and I am taking Friday off this week, and well, dammit I got confused on several fronts.

[drlava]

Here is a wav file that maxes out the DAC, so you can set the gain pot accurately without an oscilloscope. Just be sure to compensate for windows media player channel gain offsets as shown in previous posts in this thread (if you use WMP to play this file). When playing this file, after the offset pot has already been adjusted for 0V output during mute, adjust the gain pot till your multimeter reads 5V (or -5V for inverting audio cards).

[Things]

I'll probably make another one just for kicks.

James.

Damn, I dont even have 1, and your making them for fun!

[James Lehman]

Damn, I dont even have 1, and your making them for fun!

I have made several, including the very first one, ever, sometime in 04, before I even had a laser projector. I used an old vector scope.

James.

[drlava]

So did anyone demonstrate playing laseroids with this at selem?

[James Lehman]

No. As a matter of fact, very little of LaserBoy was shown on my laser projector. Most of the time was spent adjusting and aligning it with still images like circles and stuff and the rest of the time Dean was playing his abstract creations from his Visual BASIC project he calls LaserWave.

James.

[seanharrison]

Here is a wav file that maxes out the DAC, so you can set the gain pot accurately without an oscilloscope. Just be sure to compensate for windows media player channel gain offsets as shown in previous posts in this thread (if you use WMP to play this file). When playing this file, after the offset pot has already been adjusted for 0V output during mute, adjust the gain pot till your multimeter reads 5V (or -5V for inverting audio cards).

I have done this, i have 5 channels setup to 0volts silent, and 5volts with that wave file, But my 6th channel just wont set. i can get it to 5volts with the wave playing, but when i stop the wave or mute then mixer it reads bout 2.6volts no matter when i do to the offset, Any idea's ?

Sean

[drlava]

I have done this, i have 5 channels setup to 0volts silent, and 5volts with that wave file, But my 6th channel just wont set. i can get it to 5volts with the wave playing, but when i stop the wave or mute then mixer it reads bout 2.6volts no matter when i do to the offset, Any idea's ?

Sean

My guess is a bad solder joint. measure the voltage out of the sound card at that channel and compare it with the other channels. If it's the same, inspect that channel for cold or broken solder joints and lifted traces.

[Fripz]

I'm having a little problem with the Dac/Amp card and blanking on my newwish 100 mW laser. I'm getting tails on the lower dots in the ILDA frame.
Is there anyone else running these cards with Spaghetti and TTL controlled laser module?

// Fredrik