Re: [linux-audio-user] Clipping from USB audio device [WAS: command-line recording software?]

Kai Vehmanen wrote: Works, I've attached the output of 30 seconds analysis from my amp as source, as well as the portable CD player which doesn't have the clipping problem. I've also attached kern.log messages, which will explain why alteration of my mixer controls makes no difference to the clipping. This USB audio device is very simple, all it does is convert analogue to digital signal. Its worth noting that the clipping also occurs within windows and on another PC. aumix -d /dev/mixer -I aumix -d /dev/mixer1 -I are accessible, however make no difference to the clipping from the amp source, including IGain. Muting all parameters within aumix makes no difference to the signal. Would it be possible I've bought a dud analogue-digital converter, which suffers clipping at normal line volume? Thanks again for your help. Tim sig@debian:~$ ecasignalview -f:16,2,44100 /dev/dsp1 null (audiofx) -- Amplitude statistics ----------------------------- Range, pos/neg, count,(%), ch1...n Pos -1.0 dB: 27873,2.08% 34558,2.57% Pos -2.0 dB: 16638,1.24% 18953,1.41% Pos -4.0 dB: 48725,3.63% 52037,3.88% Pos -8.0 dB: 139288,10.38% 144902,10.79% Pos -16.0 dB: 247324,18.42% 239696,17.86% Pos -32.0 dB: 168665,12.57% 158772,11.83% Pos -64.0 dB: 30891,2.30% 29415,2.19% Pos -inf.0 dB: 1330,0.10% 1214,0.09% Neg -inf.0 dB: 1273,0.09% 1233,0.09% Neg -64.0 dB: 30584,2.28% 28874,2.15% Neg -32.0 dB: 160975,11.99% 152850,11.39% Neg -16.0 dB: 229714,17.11% 225017,16.76% Neg -8.0 dB: 140411,10.46% 142400,10.61% Neg -4.0 dB: 51498,3.84% 55201,4.11% Neg -2.0 dB: 17539,1.31% 19828,1.48% Neg -1.0 dB: 29608,2.21% 37386,2.79% (audiofx) Peak amplitude, period: pos=0.99997 neg=1.00000. (audiofx) Peak amplitude, all : pos=0.99997 neg=1.00000. (audiofx) Clipped samples, period: pos=22779 neg=29496. (audiofx) Clipped samples, all : pos=22779 neg=29496. (audiofx) Max gain without clipping, all: 1.00000. (audiofx) -- End of statistics -------------------------------- sig@debian:~$ ecasignalview -f:16,2,44100 /dev/dsp1 null (audiofx) -- Amplitude statistics ----------------------------- Range, pos/neg, count,(%), ch1...n Pos -1.0 dB: 0,0.00% 0,0.00% Pos -2.0 dB: 0,0.00% 0,0.00% Pos -4.0 dB: 47,0.00% 20,0.00% Pos -8.0 dB: 13221,1.01% 6771,0.52% Pos -16.0 dB: 211236,16.07% 189655,14.43% Pos -32.0 dB: 372602,28.34% 394014,29.97% Pos -64.0 dB: 61800,4.70% 67646,5.15% Pos -inf.0 dB: 2547,0.19% 2768,0.21% Neg -inf.0 dB: 2406,0.18% 2687,0.20% Neg -64.0 dB: 60550,4.61% 66711,5.07% Neg -32.0 dB: 361757,27.52% 384739,29.27% Neg -16.0 dB: 216409,16.46% 194953,14.83% Neg -8.0 dB: 11982,0.91% 4596,0.35% Neg -4.0 dB: 3,0.00% 0,0.00% Neg -2.0 dB: 0,0.00% 0,0.00% Neg -1.0 dB: 0,0.00% 0,0.00% (audiofx) Peak amplitude, period: pos=0.69818 neg=0.65366. (audiofx) Peak amplitude, all : pos=0.69818 neg=0.65366. (audiofx) Clipped samples, period: pos=0 neg=0. (audiofx) Clipped samples, all : pos=0 neg=0. (audiofx) Max gain without clipping, all: 1.43229. (audiofx) -- End of statistics ------------------------------- Jun 5 18:36:32 debian kernel: hub.c: USB new device connect on bus1/3, assigned device number 2 Jun 5 18:36:32 debian kernel: usbaudio: device 2 audiocontrol interface 0 has 1 input and 1 output AudioStreaming interfaces Jun 5 18:36:32 debian kernel: usbaudio: valid input sample rate 44100 Jun 5 18:36:32 debian kernel: usbaudio: device 2 interface 2 altsetting 1: format 0x80000010 sratelo 44100 sratehi 44100 attributes 0x00 Jun 5 18:36:32 debian kernel: usbaudio: device 2 interface 1 altsetting 0 does not have an endpoint Jun 5 18:36:32 debian kernel: usbaudio: valid output sample rate 44100 Jun 5 18:36:32 debian kernel: usbaudio: device 2 interface 1 altsetting 1: format 0x80000010 sratelo 44100 sratehi 44100 attributes 0x00 Jun 5 18:36:32 debian kernel: usbaudio: registered dsp 14,19 Jun 5 18:36:32 debian kernel: usbaudio: constructing mixer for Terminal 3 type 0x0304 Jun 5 18:36:32 debian kernel: usbaudio: no mixer controls found for Terminal 3 Jun 5 18:36:32 debian kernel: usbaudio: constructing mixer for Terminal 7 type 0x0101 Jun 5 18:36:32 debian kernel: usbaudio: no mixer controls found for Terminal 7 Jun 5 18:36:32 debian kernel: usb_audio_parsecontrol: usb_audio_state at c2509e40