I observed that the input level to the soundcard
- Soundblaster with PCI 64V - is indicated on screen by its mixer
when using Argo.

if SpecLab is used there is no indication - see attachment.
how come that? is it intenionally done?

I think one of the differences between Argo and SpecLab is, that SpecLab makes no attempt at all to change the soundcard's mixer settings (you must do that manually) while Argo has a kind of setup routine which modifies the settings to achieve a reasonable input level (that means without overloading the analog input and without wasting too much of the ADC's resolution).

   Wolf is mixing up Spectran and Argo....  what Wolf describes is more or less what Spectran does,
but not Argo... Spectran, as it does real-time filtering of the audio signal to apply bandpass, noise reduction
and CW peaking filters, needs to use the sound card in full-duplex mode.  This implies messing a bit up
with the mixer.  Argo, on the other side, just reads from the sound card the incoming audio, no audio output
is done by it, so Argo keeps its fingers far away from the mixer... the compatibility problems that
Spectran experiences with some sound cards (notably the PCI-64 and some laptop chips) derive from this,
i.e. the variety of different mixer implementation architectures found around, thanks to the sloppy specifications
in this area published by some Bill's underling.

About Uwe's question, frankly I have no answer... Uwe, how does that level meter behave when no
program (neither Argo nor Speclab) is running ? That could give some hints.

73  Alberto  I2PHD