@jaytor thx for giving potential technical reasons for selecting one streamer over another, but I believe there is an easy solution for the issues you describe.WIth your assumption that streamers can get bits correctly to the DAC, all the DAC designer would need to do is put a simple memory between the input bits from the streamer and the rest of the DAC. This memory can be designed so each side has its own power supply and clocks. My understanding is that DAC analog noise and timing errors occur in the digital processing and conversion to analog circuitry. The memory would assure that the analog noise and timing errors from the server would not affect this DAC circuitry.
why expensive streamers
@soix and others
I am unclear about the effect on sound of streamers (prior to getting to the dac). Audio (even hi-res) has so little information content relative to the mega and giga bit communication and processing speeds (bandwidth, BW) and cheap buffering supported by modern electronics that it seems that any relatively cheap piece of electronics would never lose an audio bit.
Here is why. Because of the huge amount of BW relative to the BW needs of audio, you can send the same audio chunk 100 times and use a bit checking algorithm (they call this "check sum") to make sure just one of these sets is correct. With this approach you would be assured that the correct bits would be transfered. This high accuracy rate would mean perfect audio bit transfer.
What am I missing? Why are people spending 1000's on streamers?
thx
- ...
- 191 posts total
That is not quite correct. The buffer memory on the DAC is there to ensure there is no underflow - that is the data will always be there. The memory buffer is not intended to isolate the noise. The noise from the streamer can potentially affect the DAC timing. This is true for asynchronous USB. The noise on the ground and supply of the streamer can inject directly to the DAC circuitry. That is why some DAC uses optical isolation which minimize the coupling hence reduce the noise. For S/Pdif it is a little bit different but in this case instead of a streamer, you have the transport noise affecting the DAC.
|
@andy2 there are many types of memory and storage. I am saying if there is an issue with noise coming through the streamer interace a designer could easily solve the issue. All they need to due is use something called an asynchronous fifo. The sole purpose of this fifo would be to take care of the streamer noise. The buffer memory you mention would be a conmpletely different piece of hardware performing a different function. I sure there are multiple different memory elements in a DAC. |
I don't think the FIFO (or what I called a memory buffer) can isolate the noise. I think you may be referring to data jitter - I am talking about ground and power supply noise. The noise from the streamer can inject directly to the ground and power supply of the DAC. I am not sure that the FIFO can fix that. As for data jitter, yes the FIFO can eliminate that if you are using asynchronous USB interface. All you have left is the jitter of the DAC clock itself. |
- 191 posts total