Usb or Optical

Im interested in the Pink Faun Card, how money we talking ?. If im going to notice it and its not to much money im game.

Well did some searching and its not cheap and seems like not a common card you could find on ebay used.  So are we talking like ohhhhh yeah i can really hear the difference ?

It depends on the quality of the USB controller. I've seen some devices (Raspberry Pi) where it seems to make a lot of difference. I always go optical or Spidf whenever possible. 

All things considered, USB should be better. It does depend on the interfaces though. Optical has the advantage of minimal electrical noise contamination, but is, in general, much higher in jitter. I have had very good results with an MIT optical cable but for your application USB is the way i would go. As I am learning of late, jitter has a serious impact on sound quality, much more so (i would think), than ‘noise’. I’ve now heard a jitter-free signal delivered to a familiar system and the difference when clearing jitter is to me, quite remarkable. To me it would suggest that the digital reconstruction filters of average DACs / digital interfaces get the job a bit messed up. I am now a believer that clock-timing is so important for best results.

Just to throw a monkey wrench into this. Another option that hasn't been mentioned is a second ethernet port on server, this way you avoid the lousy motherboard issues with usb or optical. Simplifies network as you can do server>FMC>streamer/usb renderer or streamer dac. I use this configuration with Sonore OpticalRendu as streamer/renderer. You can also do server>whatever ethernet devices you like. This also eliminates the need for a network switch and the added cabling necessary with it.

When speaking of optical here, I'm not talking about Toslink.

People need to keep this conversation on track. Toslink has no bearing in streaming, toslink is inferior optical connection between two digital devices, generally cd transport. This thread is steaming oriented, we're talking about network optical. Network optical does not add jitter, op has rare optical input streamer dac. If his usb sounds better its because either optical out on server inferior or optical input on streamer dac inferior or combo of both. I'd guess usb on streamer dac being superior as this technology has been around long enough so  most dac manufacturers  allocate most resources here. I've observed usb usually outperforms I2S inputs on most dacs, theoretically I2S should be superior as native protocol within dacs.