[Nympho]

I need a USB in for my Microsoft Surface Pro and Optical SPDIF out for my Digital Sound Processor in my car. Are there any cheap DACs with decent quality?

 

[billybob_jcv]

Hmm - I can't think of any portable DACs with an optical out. The Fiio E10K has a coax out, but not optical.

I'm curious - why go from USB->Optical? Why not just go USB->analog line out and just let your car provide the amp? Does your car DSP have any better of DAC than you could get for the USB port?

 

[Nympho]

Doesn't need to be portable I already am going to make a 12volt distribution block. It is a Helix DSP and it needs an optical in, I am trying to go without a head unit. I am going fully active in the car with channel separation so I am using the DSP to control everything.

 

[PurpleAngel]

  I need a USB in for my Microsoft Surface Pro and Optical SPDIF out for my Digital Sound Processor in my car. Are there any cheap DACs with decent quality?

Going from USB to optical is not a DAC function.
What you are looking for is called a converter.
 
There are USB DACs that also come with the converter function.
http://www.ebay.com/itm/130854717769?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

 

[Nympho]

  Going from USB to optical is not a DAC function.
What you are looking for is called a converter.
 
There are USB DACs that also come with the converter function.
http://www.ebay.com/itm/130854717769?_trksid=p2060778.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

I saw that but how much distortion is it going to add to the signal?

 

[seeker moc]

I would assume none, as long as it's properly designed. It's just converting digital USB/electrical data to digital SPDIF/optical data. There should be no change in the data itself. As stated before, this is not working as a DAC in this configuration, as there's no digital-to-analog conversion involved.

 

[billybob_jcv]

Ahh - OK, your Helix is a preamp/DAC with a SW equalizer and other tricks built into the firmware. Looks like it has a good Burr-Brown DAC. I agree with the other posters, you are converting USB digital to SPDIF/TOSLINK digital. With digital-to-digital, as long as the bits and timing are good, there shouldn't be audible distortion. I'm sure someone would be more than willing to sell you super special $500 USB & optical cables that will claim otherwise, but that's a debate for another forum.

 

[Nympho]

Thank you everyone for your help!