Before asking about digital audio: READ this Digital Audio Primer

[ldj325]

Some of what's in this thread I've known, and a lot that I haven't known. On both accounts this thread is very useful to clarify and educate.

I also appreciate that this thread has been kept on track towards the intent of the OP.

Thanks for the great work from Fallen Angel and the others knowledgeable posters who've been doing the heavy lifting.

 

[anoobis]

Just one comment on an otherwise very educational post.

I can understand the dislike of the term 'USB DAC' as it is not entirely accurate, however, what else do you suggest?

People are going to use abbreviations and short phrases and I don't think 'USB DAC' is particularly ambiguous. In fact, I think adding USB to the name helps as it immediately indicates a specific use (with a computer).

 

[DoYouRight]

Thanks! I just wish I could get a way to use optical with my linux laptop

 

[nickfrye]

Great infos there mate. pretty much answered my questions i was about to ask. Thanks.

 

[kraychik]

Great thread, it's mostly over my head, but hey that's what homework is for. Thanks to all the contributors!

 

[DoYouRight]

What do I need to buy to hook i2s on buffalo to my laptop? would a modded 0404 do it? any help FallenAngel, is greatly appreciated, master -_-

 

[FallenAngel]

That's quite a specific question, please start a new thread. You need something that plugs into your laptop and outputs I2S (stating the obvious, but that's kind of the idea). What plugs into a laptop: USB or PCMCIA. As I know of absolutely no PCMCIA card that outputs I2S, lets go with USB: For that there are a few USB to I2S converts, including one by TwistedPearAudio, there's an idea.

 

[DoYouRight]

removed - pointless, no bearing on this particular post.

 

[DoYouRight]

removed - pointless, no bearing on this particular post.

 

[DoYouRight]

thanks for the detail and care for this, helped me out alot with my system FallenAngel your the man!

 

[the chemist]

Hopefully this is within the scope of this article. In reference to DAC with USB receivers, I was curious if you could clarify this statement "Even USB 1.1 is capable of 24bit/192kHz, it just needs drivers to be written and USB receivers to be made to those standards." My computer knowledge is a bit lacking but what exactly needs to be done for drivers and USB receivers to be made in 24bit/192kHz?

I see your example of EMU 0404 USB for USB 2.0 protocol, do you have one for USB 1.1? Maybe this is not a huge deal as most computers seem to be USB 2.0 by now. Also is there a difference if you choose a method such as the Xindak-05 DAC which can upgrade the digital signal recorded in PCM format of common CD player to 24Bit/192Khz vs something like the EMU?

I would hate to get an amp that is working with a 16-bit depth and 48kHz sample rate.

Edit: sticky this great thread!

 

[FallenAngel]

USB 1.1 standard (at 12MBps) is fast enough to transmit a 24bit/192kHz stream without being the bottleneck.

What needs to be done is "simple" in theory - code the receiver to understand the stream, code a driver to send the data at whatever bit rate you want.

I don't know what you're asking regarding the Xindak-05 DAC, nothing can "upgrade" a signal - perhaps you mean upsample, in which case, lots of DACs upsample, in fact, most "modern" ones do. This is not upgrading a signal, it's resampling it.

Amps don't work in the digital domain, they are analog. Bit depth and sample rates are irrelevant.

Consider the fact that CDs are recorded at 16bit/44.1kHz.

 

[the chemist]

Quote:

Originally Posted by FallenAngel /img/forum/go_quote.gif USB 1.1 standard (at 12MBps) is fast enough to transmit a 24bit/192kHz stream without being the bottleneck. What needs to be done is "simple" in theory - code the receiver to understand the stream, code a driver to send the data at whatever bit rate you want. I don't know what you're asking regarding the Xindak-05 DAC, nothing can "upgrade" a signal - perhaps you mean upsample, in which case, lots of DACs upsample, in fact, most "modern" ones do. This is not upgrading a signal, it's resampling it. Amps don't work in the digital domain, they are analog. Bit depth and sample rates are irrelevant. Consider the fact that CDs are recorded at 16bit/44.1kHz.

yes, upsample was the word I was looking for and thank you, you cleared everything up! I did a bit more research on 16 vs 24 bit and found this thread http://www.head-fi.org/forums/f133/2...ploded-415361/

with gregorio's wise words and can't thank the both of you enough, great reads!

 

[xxbaker]

I could be wrong, but when you say "Optical TOSLINK is not a mechanical connection" did you mean to say "Optical TOSLINK is not a electrical connection?"

 

[darkarn]

Quote:

USB : This gets a little interesting as there is no all-encompassing standard. Since USB is a computer connection, it is not restricted to send-and-forget. Generally the standard employed and used is USB Audio 1.1 as the drivers for this standard are distributed with most operating systems. USB Audio 1.1 is a streaming non-error-corrected protocol with a limited of 16-bit depth and 48kHz sample rate. The PC being a smart device so Audio over USB is only limited by the drivers and interfaces. Some devices like EMU 0404 USB have used the USB 2.0 protocol and with their own drivers (as well as firmware on the unit) can achieve higher bit depth and sample rates. Even USB 1.1 is capable of 24bit/192kHz, it just needs drivers to be written and USB receivers to be made to those standards.

There seems to be a lot of confusion regarding USB Audio with terms like "USB DAC" and without a doubt, it can be confusing when such things are said. There is no such thing as a "USB DAC", there is such a thing as a DAC that has a USB receiver, sometimes they are even on the same chip, but nevertheless, it is easier to understand that those two separate devices are there even though they may not necessarily be physically separate.

Just to really hammer this down, USB is the protocol, a USB Receiver receives the data (after it has "agreed" with the computer how it will communicate and drivers have been loaded) and the computer sends the data (in which case it acts as a transport).

 
I am not sure if I am reading this wrongly; I noticed that there are USB soundcards like the Creative X-Fi HD that also allow recording from analog inputs besides playing audio as explained above. Hence, my question is, what would allow such transmission to occur? And thus, how would this affect my purchasing decision?