Recently I installed Linux Mint 17.1 KDE on a brand new computer. So far, only this problem. Using Audacity, I'm trying to capture audio streams from an external DAC-tuner connected by optical cable to a Xonar D2/PM sound card's S/PDIF input. But there's no sound input detected by Audacity or by headphones plugged into the Xonar's headphone output jack. However, music files played on the computer can be captured by Audacity and are heard through the headphones.
In PulseAudio Volume Control it's not possible to unmute the Xonar card, the onboard audio, or the graphics card – clicking on the red X beside the speaker icon associated with each of these devices doesn't remove the X. In KDE Mixer the sound devices can be unmuted/muted, and opening alsamixer in the terminal shows that nothing seems to be muted.
I want to record radio streams from the external DAC-tuner as I had been doing using Audacity and the same Xonar sound card in my previous old computer running Debian XFCE, with only ALSA and no PulseAudio. Then, whenever the sound system was playing and the computer was also on, the sound was always audible through the headphones connected to the Xonar. I've checked and rechecked the optical cable and headphone connections several times and they seem fine. Would greatly appreciate any helpful advice. I would think that sound must be audible from the headphones if it's being processed by the Xonar and before it has any possibility of being captured by Audacity.
Some relevant information:
0 [D2 ]: AV200 - Xonar D2 Asus Virtuoso 200 at 0xd000, irq 16 1 [HDMI ]: HDA-Intel - HDA Intel HDMI HDA Intel HDMI at 0xf7930000 irq 49 2 [NVidia ]: HDA-Intel - HDA NVidia HDA NVidia at 0xf7080000 irq 17 3 [SAA7134 ]: SAA7134 - SAA7134 saa7133 at 0xf7800000 irq 17
System: Host: desktop Kernel: 3.13.0-37-generic x86_64 (64 bit, gcc: 4.8.2) Desktop: KDE 4.14.2 (Qt 4.8.6) Distro: Linux Mint 17.1 Rebecca Machine: System: Gigabyte product: Z97-D3H Mobo: Gigabyte model: Z97-D3H-CF version: x.x Bios: American Megatrends version: F7 date: 06/17/2014 CPU: Quad core Intel Core i7-4790 CPU (-HT-MCP-) cache: 8192 KB flags: (lm nx sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx) bmips: 28800.2 Clock Speeds: 1: 800.00 MHz 2: 800.00 MHz 3: 800.00 MHz 4: 800.00 MHz 5: 800.00 MHz 6: 800.00 MHz 7: 3601.00 MHz 8: 800.00 MHz Graphics: Card-1: Intel Xeon E3-1200 v3/4th Gen Core Processor Integrated Graphics Controller bus-ID: 00:02.0 Card-2: NVIDIA GF119 [GeForce GT 610] bus-ID: 01:00.0 X.Org: 1.15.1 drivers: nvidia,intel (unloaded: fbdev,vesa,nouveau) Resolution: email@example.com GLX Renderer: GeForce GT 610/PCIe/SSE2 GLX Version: 4.4.0 NVIDIA 331.113 Direct Rendering: Yes Audio: Card-1: Intel Xeon E3-1200 v3/4th Gen Core Processor HD Audio Controller driver: snd_hda_intel bus-ID: 00:03.0 Card-2: C-Media CMI8788 [Oxygen HD Audio] driver: snd_virtuoso port: d000 bus-ID: 04:01.0 Card-3: NVIDIA GF119 HDMI Audio Controller driver: snd_hda_intel bus-ID: 01:00.1 Sound: Advanced Linux Sound Architecture ver: k3.13.0-37- generic Network: Card: Intel Ethernet Connection I217-V driver: e1000e ver: 2.3.2-k port: f080 bus-ID: 00:19.0 IF: eth0 state: up speed: 100 Mbps duplex: full mac: <filter> Drives: HDD Total Size: 1000.2GB (0.7% used) 1: id: /dev/sda model: ST1000DX001 size: 1000.2GB Partition: ID: / size: 28G used: 6.6G (26%) fs: ext4 ID: /home size: 875G used: 408M (1%) fs: ext4 ID: swap-1 size: 16.00GB used: 0.00GB (0%) fs: swap RAID: No RAID devices detected - /proc/mdstat and md_mod kernel raid module present Sensors: System Temperatures: cpu: 29.8C mobo: 27.8C gpu: 0.0:36C Fan Speeds (in rpm): cpu: N/A Info: Processes: 221 Uptime: 1 min Memory: 895.0/15909.2MB Runlevel: 2 Gcc sys: 4.8.2 Client: Shell inxi: 1.8.4