[pulseaudio-discuss] Mic Boost on AC97 audio causes bad behavior of mic volume control

[Wilck, Martin]

On Do, 2015-04-30 at 15:00 +0530, Arun Raghavan wrote:
> > Yes, software amplification will in general cause a more noise than
> > doing the same amplification in hardware (assuming an analog amplifier),
> > but as you pointed out yourself earlier, we can't just switch the
> > Capture and Boost control order, since on some hardware the Boost
> > amplifier is very noisy. You're probably right that the Boost control
> > should be separate from the normal volume slider, but we don't currently
> > have a mechanism to expose the Boost control in UIs.
> 
> We do have the idea of a base volume that provide UI hints for this case.

The base volume may need to be calculated differently then. In my case
the HW base volume ("Unamplified") is 0dB capture (on a -18..+30dB
scale) and 0dB Boost, thus 66dB below the maximum or 8% on the UI scale.
That's a bit low for my taste, it's hard to move the slider correctly in
the small 0-8% range. If the Boost isn't merged, the base volume in the
UI is at -30dB / 32%.

Martin