Exploring Visual Analyser (VA)

[Terry McGee]

Ah, Pano, perhaps you're running the 2011 Version (last stable version)? I'm confidently striding off into the future (probably at some personal risk!) on the 2012Beta version. Seems pretty solid.

Go to:

Visual Analyser 2011 XE

Click on "Beta available" at top right of screen.

You can "Log on as guest" to avoid needing to register. Click Latest VA version, then
click on VA2012beta.zip at bottom

Terry

[Pano]

Got it, thanks. I was on the 2011 version.

Funny to watch a spectrum analyzer in action that has the 88 piano notes

[Terry McGee]

Are some of them black and some of them white?

Terry

[Terry McGee]

I've just posted something on the Equipment forum which relates to integrating computer-based testing with pre-existing hardware gear. It may spark some thoughts if you are thinking about using VA with a front end, eg the one in Nuova Elettronica.

An audio test bench control unit?

See you over there if it's of interest!

Terry

[Pano]

Originally Posted by Terry McGee

Are some of them black and some of them white?

LOL! No, that would be cool, tho.

[bcmbob]

Here is a real back to basics question.

My primary use of this software for now, is getting information on power amps. The docs deal with feeding the signal to both the program and a speaker. What is the preferred method for this setup - the use of "Y" cabling or a mixer arrangement. I'm assuming the mixer would require an additional calibration step.

[Pano]

I do this by using the right channel out to the amp, the left channel of the soundcard as input. Would that do what you need?

[bcmbob]

That sound simple enough. Also allows for checking possible differences between channels with a simple swap.

Thanks

[MelB]

Terry thanks for putting this together. Great job! I await your next installment.

[Conrad Hoffman]

Using two signal generators I fooled with the A cross B and B cross A. It definitely seems to be a correlation function, but after reading about such I may not be smart enough to know what to do with it. Both signals seem to be displayed in the spectrum area in a combined fashion. The scope area appears to give the correlation function, going off scale when the frequencies match. Maybe somebody can give a better description of what cross correlation is good for. It might be useful to download the manual for a commercial 2-channel vibration analyzer like SRS and read the section on correlation functions, as I know they have them.

BTW, I plugged in my Wavetek and my HP8903, which have an order of magnitude THD difference, and VA seemed to read them perfectly after using the calibration button. It read more than 10X too high before doing that. I'm not exactly sure why that calibration is even necessary.