Stereo Tool

When I set up an Input into the SCA Input I need to reduce the Post Amp to -4 to stop the output from overload (flashing red). The SCA signal is compressed/limited before it goes into ST as in a previous message Hans mentioned that the SCA Input was not processed in any way other than placed onto the MPX output.

My guess is the output meters read the output of the combined MPX signal and not just the main program component?

Clipper

Hm, this might be a bug. Can you check if it works with/without composite clipping? I might have missed this one in composite clipping mode...

Hi Hans,

I will do some tests tomorrow to look further into this, as I just tried it with the 32 bit version and it is fine. It is the 64 bit version I have on the station machine which gives me the trouble. I'll be in there tomorrow so I'll check it with the 32 bit version on that machine and see if I get the same peaking results.

Thanks,
Clipper

Hi Hans,

Checked it out and it seems to be the interface we are using. We're setting it up on machine we'll use for a demo on our network monthly Techo's Day this Saturday and we have used a USB Audio Interface to get the signal for the SCA into the machine. Signal monitors fine but causes the Output meters to flash red, well more like stay red.

We weren't suspecting the interface so looked and checked everything else. Unplugged the USB audio interface and replaced it with a second audio card and there was no issue any further. When the rep who left us the interface to have a "play" with returns we'll mention it to him.

Thanks,
Clipper

Now I'm completely confused... The SCA signal is FM-modulated, so it doesn't make any difference what signal is transmitted - it's always equal in strength. And the sound card should not have an effect on the ST meters....

Hans,

You're confused? I wish we had some documentation to know what we are doing is right.

I am only having that issue on the station machine running Windows 7 x64 with the 64 bit version of ST.

I am going to try it with the 32 bit version of ST tomorrow.

On both versions when I select to have the SCA on a 2nd thread the display of the SCA on the output scope disappears. Comes back when I select the 2nd thread off.

Clipper

Hans,

What level should the SCA be to the input of ST? We're presenting an input to the machine that gives "0" peak to the input level meter of the sound card but what I notice is, it sends the Declipper meter to (mostly) full red display. Using this analogue input for the SCA signal I have to turn the Post Amp down to -1.6 to stop the output meters giving a constant red display.

I noticed FM Transmitter -> SCA, the input is set at 10% which I am guessing does the reduction in level to that required. Or do I need to reduce the input to the sound card accordingly?

Thanks,
Clipper

SCA signal is FM-encoded in the audio signal. Which means that it doesn't matter for the output level how loud you input it - the only thing that influences that is the slider that you mentioned.

If you need to lower Post Amp that's a bug in the software. (If the signal itself is ok I wouldn't do that, and instead just lower the volume going to the sound card).

The declipper meter is always red! - it shows input level (red) and output level (center bar, also red).