LFI modulation/blanking

[Benm]

I've been using LFI for some time, but i've never been able to get analog modulation to work properly. No matter how i configure things, it seems to output TTL - dimming individual color channels seems to have to effect whatsoever, unless i dim them to zero.

I've been looking at the soundcard output on a scope, and that confirms it eiter modulates at 100% power (ttl style), or not at all. Does anyone have any insight in what i may be doing wrong?

 

[ElektroFreak]

What palette setting are you using? For analog you need to be using the "normal" palette:

If those settings are correct, are you 100% sure the frames you're using are analog?

 

[Benm]

I have put it on 'normal' mode, although i did try all the other ones too just to check if it made a difference. It does, invert obviously results in inverted blanking etc, so the controls work.

Do you have some ilda frame for me that you are sure provides analog modulation? I'd really appreciate that.

Problem is that i first thought i miswired something, but looking at the soundcards output on the scope, it just provides maximum or no output if it adjust the color sliders in the main screen.

 

[ElektroFreak]

I'm at work right now, but I should be able to provide you with an analog frame sequence this evening..

Since the sound card only does what the computer tells it, I doubt the problem is your DAC. It almost has to be either a software setting or TTL frames..

 

[Benm]

I agree with that assesment. When i play audio files through those channes i can clearly see the analog modulation at work, so the hardware should be okay. Please send me some test frame(s) to verify the problem

 

[ElektroFreak]

This is a common frame for testing color.. it should provide you with several different signal levels other than just off or on.

http://dl.dropbox.com/u/2843911/Color.ild

 

[ElektroFreak]

So did you have a chance to try the above frame yet Benm? If so, did it help you get things sorted?

 

[Benm]

I did.. with somewhat surprising results, see these scope shots of the frame you posted. The yellow line is the idle state (i.e. no show running), all traces are DC coupled to the scope.

The red blanking signals look okay, but the green ones look to be inverted in a strange manner. These traces are the direct output from the soundcard, no compensation amp in between or anything.

There is definitely something wrong here: i wonder why the blanking singal actually goes below its idle state, and why the outputs of the green and red channels look so different.

 

[Benm]

Oh, and this is what the projection looks like - ignore the blanking delay errors for now.

 

[ElektroFreak]

Hmm.. I'll have to think about that one..

You're using the c-media card?

 

[Benm]

Yup, the one from dealextreme.

I think i'll have to plough through the ini file to find any errors, the blanking on the green channel is mucked up for sure. At least its not a hardware problem, since that is equivalent to that of the red channel.

 

[ElektroFreak]

Out of curiosity have you tried reinstalling the drivers? Also, if you're referring to ezauddac.ini, you could always just overwrite it with a fresh copy by reinstalling your software.

 

[Benm]

I'll try installing a fresh copy to make sure... gotta make time for some serious scope staring i'm affraid though