(I'll try answering some of my questions.) John Sigler wrote: > I have an RME AES-32 PCI board. > http://www.rme-audio.de/en_products_hdsp_aes32.php > > [...] > > When I boot, every channel has its volume set to 0. > Is this done by the board's firmware? http://lxr.linux.no/linux/sound/pci/rme9652/hdspm.c#L3396 http://lxr.linux.no/linux/sound/pci/rme9652/hdspm.c#L965 Apparently, it's not the board's firmware, it's the device driver which mutes every channel at initialization. Does anybody know why this is done? > I used amixer to change the volume. > > Simple mixer control 'Chn',1 > Capabilities: volume volume-joined > Playback channels: Mono > Capture channels: Mono > Limits: 0 - 65536 > Mono: 32768 [50%] > > What is the meaning of the level? > Does 100% mean the signal is left unmodified? > and 50% means the amplitude is multiplied by 0.50? http://lxr.linux.no/linux/sound/pci/rme9652/hdspm.c#L377 #define UNITY_GAIN 32768 #define MINUS_INFINITY_GAIN 0 So, volume = 32768 means "leave the signal as is" and volume = 0 means "mute the channel". Is that correct? What would volume = 16384 and volume = 49152 mean? (What is the scale?) Regards. ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Alsa-user mailing list Alsa-user@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-user
