[ddgtr]

Hi,

I have a few questions about the BDA-1 and I apologize in advance if they have already been discussed...

I am mainly streaming music from my pc to the bda-1 via usb because I do not trust my sound card (realtek) to output without messing with the sound at all.

As I am getting more 24bit 96KHz recordings in FLAC format via foobar2000, I would like to know how the BDA-1 handles such an incoming signal via usb when it can only accept 16bit 48KHz.  Assuming I have the upsampling disabled,  what exactly is going on?  Does the BDA-1 take the incoming 24bit 96Khz and downsamples it to a 16 bit 32KHz or 48KHz?  Because it obviously cannot pass it.  When that happens, how much of the quality is lost?  I have quite a bit invested in audio equipment and want to be sure I am getting the cleanest possible signal path to my speakers.

I thought the whole point of having a USB input was to bypass unreliable sound cards.  In my opinion, a high quality dac should be able to accept higher bit rates via the usb input.  We would really like to see Bryston address this in an upcoming firmware.

If I am off on any of the above points someone please correct me.

That said, I really like the dac.  It has been working great without a single problem.

Thanks in advance

[drubin]

I believe it will require more than a firmware upgrade for the Bryston to handle higher sampling rates via USB.  The high-rez files are great and it would be a shame to downsample them.

If your computer has Toslink output, that will give you what you want and should sound better than the current USB solution.  If not, I recommend you get a USB to S/PDIF converter that can process 24/96, such as the Bel Canto, Empirical Audio or Wavelength.  Or, if your computer has Firewire output, go that route instead.

[ddgtr]

Thanks drubin!

My pc does not have an optical out, but it does have a spdif digital coax out.  The card can also output 24/192 but I do not know what goes on there as I could not find enough documentation on that.  I just want to make sure that the signal gets out to the dac in it purest form and I was under the impression the usb was the way to go in this case.

You mentioned firewire, how would I connect that to the BDA-1?

I've tried to research sound cards, but either I'm not good at it or there just isn't enough info out there.  Do you have any suggestions as to which brand makes a card that can just pass through an incoming signal?

Thanks again!

[alexone]

Hi,

I have a few questions about the BDA-1 and I apologize in advance if they have already been discussed...

I am mainly streaming music from my pc to the bda-1 via usb because I do not trust my sound card (realtek) to output without messing with the sound at all.

As I am getting more 24bit 96KHz recordings in FLAC format via foobar2000, I would like to know how the BDA-1 handles such an incoming signal via usb when it can only accept 16bit 48KHz.  Assuming I have the upsampling disabled,  what exactly is going on?  Does the BDA-1 take the incoming 24bit 96Khz and downsamples it to a 16 bit 32KHz or 48KHz?  Because it obviously cannot pass it.  When that happens, how much of the quality is lost?  I have quite a bit invested in audio equipment and want to be sure I am getting the cleanest possible signal path to my speakers.

I thought the whole point of having a USB input was to bypass unreliable sound cards.  In my opinion, a high quality dac should be able to accept higher bit rates via the usb input.  We would really like to see Bryston address this in an upcoming firmware.

If I am off on any of the above points someone please correct me.

That said, I really like the dac.  It has been working great without a single problem.

Thanks in advance

hi, ddgtr!

the BDA-1 can 'only' handle 16bit 32k-48k with USB. good question what happens if you feed it with hi-res music...maybe a downsampling? not sure on that. i've never tried it as i find that USB is not the best solution for music signal transport. but my understanding is that the BDA-1 will upsample low res music (even via USB) by engaging the upsampling button (as you know).
however, if your card has a coax out then try to arrange a 44.1k output and let the BDA do the upsampling.
if you are looking for a soundcard that can handle higher formats try ESI Juli@. the interesting thing about this card is that it can be used in balanced OR unbalanced mode (analog).


al.

[James Tanner]

Hi ddgtr

On the BDA-1 if you use USB it is capable of anything up to 48/16.  The way USB works is it handshakes with your computer and tells the computer what resolution the BDA-1 is capable of.  So if your sending a 96K file 'YOUR' computer will down-sample the signal before it is sent to the BDA-1.   

We use what is called 'I2S' instead of SPDIF (which eliminates one interface step) at the USB input on the BDA-1 and then WE use a very high quality state of the art up-sample chip in the BDA-1 to do the up-sampling rather than allowing the unknown computer up-sampler to do it. If you play a 96/24 file you will see that the BDA-1 will accept it as a 48/16 file and then you can up-sample that to 192/24 using the up-sampler in the BDA-1 if you wish.

USB is only capable of 96/24 at this point (as far as I know) and then only with companies writing proprietary software to implement it. When USB chips become available that can do 192/24 (as all the other inputs on the BDA-1 are capable of) then we will certainly look at adding higher res capability to the BDA-1 USB input.

Also, in my opinion, if you want the highest quality playback you are going to use SPDIF, BNC or AES-EBU inputs with a quality soundcard. Also as I have said many times I find that just because a specific DAC can do hi-resolution it does not automatically mean it has superior performance.  We have found that things like sophisticated power supply design, independent ground plains for digital and analog signals, separate circuit paths for digital and analog signals, Class A discrete analog circuits etc. far outweigh whether a specific file is 44.1 or 96K or a specfic DAC can do hi res playback..

James

[ddgtr]

James,

Thank you very much!  It is this kind of service that we customers really appreciate and this is why we keep coming back!!  And I do agree with your statements about a better power supply, etc that are more impotant...  Like I said, I really like the dac and I highly recommend it!

If you can clarify one thing in your answer above:  "So if your sending a 96K file 'YOUR' computer will down-sample the signal before it is sent to the BDA-1."

Does this mean that even though I use the USB interface, my computer's sound card will still get involved and WILL down-sample the signal before sending it out?  Or is it the program I'm using (in my case foobar2000) that will down-sample it?
The foobar2000 "sees" the BDA-1 in it's "preferences" menu, where it allows me to select it over the computer's sound card.

Also, you are recommending spdif for highest quality playback.  I am not overly concerned about 24 bit hi rez playback at this time because I don't have enough of it.  So given the 16/44 material, for best playback quality would you still advise SPDIF over USB?

If I do get one of the highly recommended sound cards, I would need to disable any kind of processing or upsampling in it so that the BDA-1  can do its thing, correct?

Last, based on your lab testings, is there a particular card you recommend that will allow for unaltered signal passthrough to the dac?

My main thing is that I do not want a signal to pass through 2 dacs, once in the sound card's dacs and the second time through the BDA-1...

Thanks again, James!



alexone, thank you for the reply... I will check out the card you mentioned!!

Cheers!

Dan

[James Tanner]

Hi,

Foobar 2000 is more than likely doing the downmix or it could be the windows ASIO driver - not sure on this one. The soundcard is definitely not involved in the output on USB.

I prefer the AES-EBU or SPDIF input on my windows systems at home. I have 3 setups:

1. Mac pro Laptop - optical out to BDA-1
2. Windows XP with MAUDIO 192 Sound Card SPDIF out to BDA-1 BNC in
3. Windows XP with Lynx 16E Sound Card AES-EBU out to BDA-1 AES-EBU in.

james

[ddgtr]

Thank you James!!