USB Audio DAC mod + LaserBoy Correction Amp

[carmangary]

I need to eventually build one of the Sound Card DACs so I can test and see how it looks. First, I think I just found an issue with the color control in the spaghetti sound card driver. I am working with DrLava to sort that out. Second, Spaghetti doesn't support TTL control. Everything is analog and that will cause problems for TTL modulate laser. I will work on adding support for TTL. It will be easy to do. Also, try playing around with the blanking optimization settings on the Scanner Settings window and make sure it is enabled. It will usually get rid of any tails when everything is working properly.

[James Lehman]

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

Yes. You have a bad solder joint. I did exactly the same thing when I built my first kit. When I snipped the resister lead, I pulled the foil away from the board. It will be somewhere between the output of the negative 5 volt regulator, through the 20K resister and into the input of the 10K offset pot.

James.

[barold]

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

Wow that got there fast! I'm sorry you are having troubles. There goes my reputation for soldering abilities! I hope you can get it working.

If you cant fix it, I'll build up another board, TEST IT, then send it to you.

Nothing ever goes right when I try to help some one out!

Barry

[seanharrison]

Wow that got there fast! I'm sorry you are having troubles. There goes my reputation for soldering abilities! I hope you can get it working.

If you cant fix it, I'll build up another board, TEST IT, then send it to you.

Nothing ever goes right when I try to help some one out!

Barry

I am not really sure, getting a little confused with things, lol....

What are the output pinout's from the OpAmp board, is it:

1 X+
2 X-
3 Y+
4 Y-
5 R+
6 R-
7 G+
8 G-
9 B+
10 B-
11 I+
12 I-

If so its my Intensity Channel on the sound card that is dead, I tested the outputs from the sound card between the Negative and each channel reads at 2.20volts apart from the 3rd (I+) which only reads at 0.01volts. Also the processor on the Soundcard is extremely hot. Im guessing its fried.

[drlava]

If the output from the sound card for the I channel is 0V, check your speaker settings. Also, it's possible that the solder joint that the I wire connects to the card with is connecting to the ground plane around that pin, through the solder mask (assuming you're using the USB card).

[carmangary]

First make sure you are sending a signal to I. Until last night, Spaghetti would not send anything on the I channel.

[barold]

yes that is the pinout of the op amp board. The first sound card I ever had fried itself somehow also. That same chip would get really hot, but all the channels were smoked.

[James Lehman]

1 X+
2 X-
3 Y+
4 Y-
5 R+
6 R-
7 G+
8 G-
9 B+
10 B-
11 I+
12 I-

NOT QUITE! There is nothing differential about this device at all! It is purely single ended in and out. So it would be much more accurate to say this:

1 X
2 GND
3 Y
4 GND
5 R
6 GND
7 G
8 GND
9 B
10 GND
11 I
12 GND

All of the grounds are common in and out.

Since we are on this very specific subject, how do you guys deal with hooking this up to an ILDA compliant connector? My gas RGBB laser is not exactly compliant. It's got its own thing going on, so I went with that. While I was at SELEM, I finished up a USB sound card + LaserBoy Correction Amp set for buffo. His RGB projector is compliant with the ILDA spec and won't even come on unless there is an interconnect between pins 4 and 17 and +5 VDC on pin 13 to open the shutter. Pin 1 is X. Pin 2 is Y. Pin 5 is R. Pin 6 is G. Pin 7 is B. Pins 14, 15, 18, 19, 20 & 25 all need to be tied to GND. (All of this is in reference to the DB25 ILDA port, not the correction amp.) Do you have anything to add or report, buffo? Did I get it right? Have you done the "smoke test" yet?

James.

[allthatwhichis]

Have you done the "smoke test" yet?

James.

Don't mess around man... I never pass these...

[James Lehman]

Don't mess around man... I never pass these...

I'm not talking about you and your blood. I'm talking about seeing if when you hook this up to your laser projector, anything smokes or not!

James.