alidaf wrote: > To answer another question about why....Using LMS (I think) changes the > input level, which leads to a gain structure with less fidelity. As far > as I know, for digital processing or line level devices, the input gain > should be fixed and the volume increase based on amplifier gain rather > than input gain. My squeezebox has a fixed level that feeds a dac built > into my Moon amplifier and I use the amp's volume control. I used to be > able to do it via the IR blaster but that doesn't work any more. I want > to build a custom headphone amplifier with alarm clock etc., and I would > like to be able to control the volume on the box with a rotary encoder. > More for convenience than anything. Ultimately I'd like to build the > full functionality of the squeezebox, with song selection etc (also need > rotary encoders) and possibly some real analogue VU meters. Yes, I'm a > dreamer.
Hi alidaf, You need to be thinking analog and digitial volume controls. Generally an analog volume control is simply a voltage divider (pot). This changes the voltage. Most digital controls fiddle the digital signal which usually results in a loss of fidelity. Some people can hear it, I can't. So in our Squeezebox system, LMS, ALSA and some CODEC chips can adjust the volume digitally. Squeezelite has the following option to link LMS to ALSA volume control. -V <control> Use ALSA control for volume adjustment, otherwise use software volume adjustment What you really need is an ordinary pot in your analog line level signal just like traditional pre amps/power amps - i.e. an analog solution. BTW: Amplifier gain usually refers to the feedback loop which sets to overall gain of an amplifier. This is very rarely adjustable. It is usually set by 2 resistors. regards Greg ------------------------------------------------------------------------ Greg Erskine's Profile: http://forums.slimdevices.com/member.php?userid=7403 View this thread: http://forums.slimdevices.com/showthread.php?t=97803 _______________________________________________ unix mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/unix
