Having sat down to listen to music for the first time in ages I noticed that I am no longer getting bit perfect output from my RME card. I'm not sure what has happened, I'm guessing some sort of Windows update, but I couldn't see anything wrong last night.
I'm using the WASAPI interface in Widows 7 x64, co-axial S/PDIF out and tried both XBMC and Foobar2000 to play Apple Lossless files. I have a Natalie Merchant album (Ophelia) which is HDCD encoded and therefore I know all is well as the little light comes on on my DAC. Last night it was sometimes on using XBMC and didn't come on at all when playing through Foobar.
Everything still sounds fine but I know it should be able to pass a bit perfect stream to the DAC so I'm puzzled as to why this is no longer the case.
Has anyone else experienced this or got any advice on how I can get back to where I was?
Thanks
Simon
Having sat down to listen to music for the first time in ages I noticed that I am no longer getting bit perfect output from my RME card...
.... I know all is well as the little light comes on on my DAC.
And you think the red light means "bit perfect"? I don't think is possible for the DAC to know if the S/PDIF stream contains bit-perfect data or not. (It would know if it's uncompressed PCM or Dolby AC3, if the DAC can handle compressed files.)
And you think the red light means "bit perfect"? I don't think is possible for the DAC to know if the S/PDIF stream contains bit-perfect data or not.
Because the HDCD info is encoded into the LSB of the PCM stream, it actually is a very good way to verify a "bit perfect" stream because basically any modification of the audio scrambles the LSB.
Sorry to go on a tangent here,
Why wouldn't you use the DAC on the soundcard instead of SPDIF to an amp?
Wouldn't the DAC on this soundcard be extremely good?
More recent versions of Foobar2000 have built-in HDCD detection and will convert to 24-bit. I'm not sure if this is standard or by default, but if it was happening it would certainly explain the light being off.
I've got a TAG AV32R for surround duties and that's a fairly handy DAC, and a Cambridge Isomagic (if anyone remembers them) for audio - this has the HDCD light. The Cambridge has an onboard clock with a sync output which I can slave the RME's S/PDIF to, in theory reducing/removing jitter. Either way in the past they've both sounded better than the RME's analogue out.
I'll check Foobar to see if I can find any mention of HDCD.
There's still something odd going on, and I've bot changed anything so this does seem odd,
It's WASAPI up to no good.
I just installed ASIO support in Foobar and sure enough, HDCD is and therefore bit-perfect playback is steady as a rock.
So now I just need to get it into XBMC and I'm back to where I started, except perhaps using ASIO will protect me from more 'updates'
Thanks for being a sounding board guys
Simon
More recent versions of Foobar2000 have built-in HDCD detection and will convert to 24-bit. I'm not sure if this is standard or by default, but if it was happening it would certainly explain the light being off.
HDCD requires http://www.foobar2000.org/components/view/foo_hdcd (http://www.foobar2000.org/components/view/foo_hdcd) .