Do we remember this? http://alsa.opensrc.org/TwoCardsAsOne http://quicktoots.linux-audio.com/toots/el-cheapo/ HW modification , sharing one x-tal
Either just add 2 or 3 PCI or PCI-E soundcards to an old PC. OR building a "low cost pc" with 16 ( or 24 ) channels of sound outputs for around 150 Euro? Mother board have possibility to expand to 3 pci-e soundcards. Can be built as a minitower - I belive the CPU power is good enough for decoding - do I need more than 2 GB Memory for building this as a first degree decoder? http://www.asus.com/se/Motherboards/AM1MA/ 3 PCI-E 299 SEK http://wimages.vr-zone.net/2014/03/am1.jpg AMD e2-3850 350 SEK Memory DDR3 2 GB ? 300 SEK Disc or USB boot - Power and Box - recycling http://www.aliexpress.com/snapshot/6052508040.html 2 PCIE soundcards 31 USD / cards == 420 SEK 2) Based on VIA VT1723 Envy24DT multi-channel audio controller, Sampling rate up to 24 bits and 48KHz for both playing back and recording - 8 channels Would the CPU power and memory 2GB be enough for A6-5350 A4-5150 E2-3850 E1-2650 Cores / Threads 4 / 4 4 / 4 4 / 4 2 / 2 CPU Frequency 2050 1600 1300 1450 2000 1400 GPU HD 8400 HD 8400 HD 8280 HD 8240 GPU SPs 128 128 128 128 GPU Frequency 600 600 450 400 L2 Cache 2MB 2MB 2MB 1MB TDP 25 W 25 W 25 W 25 W Platform AM1 AM1 AM1 AM1 -----Original Message----- From: Sursound [mailto:[email protected]] On Behalf Of Marc Lavallée Sent: den 6 april 2014 15:37 To: [email protected] Subject: Re: [Sursound] Inexpensive USB multichannel sound card Sun, 6 Apr 2014 06:23:37 +0100, Dave Malham <[email protected]> wrote : > Lets not worry too much about silicon - it's ridiculously cheap these > days, so long as you are not going for the top end. If we are to use > cheap, ready built, USB units and not our own purpose built kit (and > that's not unthinkable, this is the age of the maker, right?) I think > it all hinges on two things, synchronisation and bit rate. For 24 bits > and 48 Khz, which is, I guess, about the lowest we'd all be happy > with, that's 1152 kilobits per second, which means for USB 2, a > practical limit of 8/10 channels per plug, all things being equal. > This is why there are 7.1 units out there. Hi Dave. The previously mentioned cheap USB sound modules are limited to 16 bits and 48Khz. When resampling 24bit sources with dithering, 16 bits is enough for domestic use. At 48Khz, that's 768Kbps per channel, and at 44.1Khz that's 705.6Kbs. So the required USB bus speed for 8 channels is 6144Kbps or 5645Kbps (maybe more with some protocol overhead). These modules work with USB 1.1, not USB 2. The USB 1.1 standard have two speeds: low at 1.5Mbps, and full at 12Mbps. So, theoretically, a single USB 1.1 bus at full-speed can handle two 7.1 sound modules at 16bit/44.1Khz. I don't know how a USB 2 hub deal with several USB 1.1 devices. I yet have to test two modules with a RPI. -- Marc _______________________________________________ Sursound mailing list [email protected] https://mail.music.vt.edu/mailman/listinfo/sursound _______________________________________________ Sursound mailing list [email protected] https://mail.music.vt.edu/mailman/listinfo/sursound
