SPDIF--->USB

Do there exist converters to go from SPDIF to USB? And if so, does a PC need to part of the mix?

Reason for asking: I would like to take the optical out of my Apple Express and run it to a USB-only DAC. Is this possible?

Not aware of any such device. Why not just go USB directly??

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Because the Apple Express does not run audio out of its USB port.

Probably not. I'm not aware of anything with a usb out that acts as an airtunes node, perhaps an appletv though I expect you'd have to patchstick the driver.

I think you'd need a new dac.

A USB device requires a host (computer) and drivers (software). So, a SPDIF to USB converter would require a computer of sorts.

Thanks,
Elias

To use Airport, i have purchase a spitfire from Fubar.
inside you can change the opa like you want and use RCA to connect your amp.
It's a cheap solution witch works fine.

Not sure if such a converter exists. Just go straight for USB if you want it.

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Asked and answered above. Twice.

Please re-read above: Because the AEX does not output audio through its USB port.

I've posted three times now the reason for my question. If I wanted to just go USB, I would, but of course the AEX does not output audio as also noted above. WHAT I WANT TO KNOW IS IF I CAN GO SPDIF--->USB WITHOUT A COMPUTER IN THE MIX. Why? Because I want to. Just go USB is non-responsive.

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go easy on him. he's building postcount

The short answer is NO, you cannot convert S/PDIF to USB because USB is a host-slave system and what you're asking for is likely connecting two slaves together.

The longer answer is yes, but there must be some logic processor in the middle. If there is a chip that listens on the S/PDIF port and translates the data to be sent through USB, it's possible, but of course you must write firmware for this chip and drivers for the computer to communicate with it. A host must understand and know how to communicate with the slave.

Generally this is what happens:

1) USB device (slave) is plugged into PC (host)

2) PC notices that there is a connection on a USB port and pings device for device ID using standard USB protocol.

3) USB device (slave) responds with with it's device ID using standard USB protocol.

4) Host must now check if it has drivers installed to communicate with this device properly. If it does, communication can start (USB host sends requests to slave and slave responds).

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I can see two ways this can be implemented.

1) This device acts as an S/PDIF receiver and sends it's data to the PC (or other smart device) through USB port. What format do you want this in? Some device has to recognize this converter and be able to communicate with it (drivers required).

2) This device complies with USB Audio 1.1, understands when a USB Audio 1.1 compliant device is connected to it and sends data using this format. No drivers necessary except in the device itself. In which case, it sounds simpler in theory but the firmware for this thing will be a headache to write. I know of no commercial product that does this, can't imagine any market that would want this, but sure it's possible and likely what you're asking for.

I think there really is one available. Check for universal adapter.

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Super small market niche that it would be very cost prohibitive to build this. I mean seriously, the only reason anybody would use this is to hook up S/PDIF output from cd player to a USB DAC and considering that I have yet to find a USB-only DAC that can't be bested by another DAC with S/PDIF input for the price of it plus this adapter that I see no reason anybody would make this thing. Well, maybe just for fun, if you consider writing firmware fun.

fallenangel said:

  Quote:

Originally Posted by Sony_R10 /img/forum/go_quote.gif I think there really is one available. Check for universal adapter.

Super small market niche that it would be very cost prohibitive to build this. I mean seriously, the only reason anybody would use this is to hook up S/PDIF output from cd player to a USB DAC and considering that I have yet to find a USB-only DAC that can't be bested by another DAC with S/PDIF input for the price of it plus this adapter that I see no reason anybody would make this thing. Well, maybe just for fun, if you consider writing firmware fun.

Click to expand...

Sorry to revive an old thread, but I'm wondering if there has possible been any change since back then.  
 
You mentioned you didn't know of a DAC of this sort.  A very unfortunate example which now exists is the ODAC.  I haven't seen any DAC which measures up to it at its price range.  I really badly want to use it paired with my interface which I use for tracking/recording and which has a S/PDIF out.  It would be really cool if somebody was able to implement this (or if someone actually did).  Even better would arguably be I guess somebody actually implementing a mod for the ODAC which allows it to support S/PDIF.  However, NwAvGuy, the creator of this device, mentioned that this wouldn't be possible.  That's total tripe however imo.  It's likely of no value to him so he felt no incentive to design it with that in mind.  It's not unheard of for a DAC to have both kinds of inputs, obviously, and it's an achievable goal to not have one stifle the quality of the other.  In any case, at the very least an alternative version can be designed with only a S/PDIF input.
 
 
Anyone know of anything?  Thanks.

Yes, there is a device which will convert USB to S/PDIF : Creative Sound Blaster X-FI HD. This external sound card will also convert S/PDIF to USB and  RCA Analog to USB among other things. It's an awesome device to get LP's to computer or iTunes to HT with or without using your pre/pro DAC.

sterling1 said:

  Yes, there is a device which will convert USB to S/PDIF : Creative Sound Blaster X-FI HD. This external sound card will also convert S/PDIF to USB and  RCA Analog to USB among other things. It's an awesome device to get LP's to computer or iTunes to HT with or without using your pre/pro DAC.

Click to expand...

Wait, you're saying for sure it will also convert S/PDIF to USB?  Really?  So if I connect a S/PDIF input and then connect an external DAC to it through USB, it would work?  It really doesn't look like it.  There's plenty of ones which do USB to S/PDIF.  We're looking for the other way around.
 
Thanks for the suggestion either way!