Hi Folks,
Quick question on bda3. I have mine connected to a Cambridge audio CXUHD which is a blue ray player WITHOUT Dac on board. It outputs video on tv via HDMI and audio to bda3 via hdmi and coax. On hdmi I can send DSD stream if I play sacd or pcm up to 192 if I play a blue ray audio disc, depending on the specific disc.
One strange thing is that when I select coax input (SPDIF1) on bda3 it says the rate is 48 while if I switch on hdmi is 96/24 as it should (same blue ray disc of course). I changed audio output on Cambridge settings from 192/24 to 96/24 to bitstream but on coax the rate is always 48. According to bda manual coax input should be able to accept signals up to 96/24.
Any hints?
Hello!
Your 'quick' question may not have a quick answer
The problem is not in the Bryston DAC but rather in the Cambridge bluray player. Obviously, it down-samples everything above 48kHz through the S/PDIF output. This is not uncommon with bluray players and was actually a major downside of this interface in almost all of the DVD players.
Try burning a CD with a 32 and 44.1kHz file and see if the BDA-3 still shows a 48kHz sample-rate.
Remember that the more modern D/A conversion techniques like delta-sigma were actually introduced alongside the first DVD machines, hence the reason why DVD players were thought to sound superior to many CD players of the time. Even if that was the case, the industry never bothered to 'improve' upon the S/PDIF spec to allow for sample-accurate playback. I seem to remember reading a whitepaper about that back in the day and I think the concern was that it would not be compatible with most outboard DACs of the time which, still depending on traditional linear-type converters, would not be able to work properly. Also, because the recording formats of the time such as Digital Audio Tape and MiniDisc did not work with sampling frequencies above 48kHz (with some exceptions), there was no real need to upgrade the specification. Professional industry didn't care either because the 44.1kHz sampling was chosen specifically to correspond to and synchronize well with the video formats of the time which is all they needed.
In a nutshell, Cambridge must have used an either older or cheaper chipset or did not choose to process the S/PDIF signal on the main DSP instead or quite simply didn't care. Still, I must say, I find it odd because I consider the brand something of a digital specialist and for a while, I was considering the same player. If I had actually bought one, I would have had the same problem as you because that is one of the things I would have liked to do with that player.
Sorry for the bad news, mate. At least I hope I managed to answer your question.
Cheers - Antun
