Convert USB to SPDIF

You can’t.  You need to add a DAC, and one that will accept usb.  And you probably need a “Player” and that can read the files on the flash drive and send them to the DAC

Hello Mahler123, I do not have a solution for your question, but a question myself. May I ask for your expertise and guidance? ow can I connect my music collection on a FLAC USB to my pre-amp listed here? My sound system is an early 80s ‘stack’ system.

None of the components are digital: Bryston 2B solid state amp, Conrad-Johnson PV-11 pre-amp, MIT 330 interconnects, MusicWave phase-equalized speaker cables, California Audio Labs CD Alpha and Delta drive, Dual 1129 turntable. B&W 803 speakers.

I would appreciate your suggestions and guidance on the matter.Thank you.

Mark Saracino

Here is an affordable solution: https://www.electricalengineering.xyz/videos/lt-usb-to-spdif-converter/
If you want something more better here it is as auxinput already mentioned.
https://apos.audio/collections/brand-spotlight-matrix/products/matrix-x-spdif-2-usb-interface

I'm running from Windows 10 laptop to Schiit Wyrd( decrapifier) then in Project box S2. Will converting usb to spiff always sound better?

There may be a cheaper way to improve your sound.  Replace your wall-wart power supply on the Project Box S2 DAC with a linear power supply such as this one:

https://www.ebay.com/itm/Hifi-Linear-Power-Supply-for-Pro-Ject-Pre-Box-S2-Digital-Preamp-and-DAC-L17-48/143261499196

That would significantly improve your sound quality at a lower cost of about $136 USD. 

You could also get a better power supply such as the LKS:

https://www.ebay.com/itm/LKS-Linear-power-supply-DC-5V-USB-5V-for-DAC-with-25VA-Talema-transformer-PSU/133558190349

Then buy a USB cable with a "Micro-USB" connector on one side for your S2 dac.

Ok, the proverbial dumb question, I'm reading this post and others, my question. is it always advised to convert USB to Spdif? I'm running from Windows 10 laptop to Schiit Wyrd( decrapifier) then in Project box S2. Will converting usb to spiff always sound better? Better in all respects. Thank you, Otto

It depends on how good the USB receiver board is in your DAC.  If your DAC has an Amanero USB receiver board with really good power supply, it's likely that you may not get much (if any at all) if you put in a USB-to-SPDIF converter box.  Also, Amanero boards usually have two separate clocks that generate the proper timing on the two main audio format sampling rates.

If you have a cheap DAC without a good USB interface, then a USB-to-SPDIF converter box is likely to improve things significantly.  In this situation, the relatively lower cost solutions such as the Matrix solution mentioned above or the Wyred 4 Sound Remedy Reclocker for $299 could be good options.  It's a little more expensive, but I would choose the Matrix X-SPDIF 2 USB Interface for $379 because it uses Accusilicon clocks which I know are excellent and I think better than the Crystek clocks typically used in these devices.  The Wyred4Sound and Matrix both use wall-wart switching power supplies (which can be upgraded to linear power supply if you want).

Or you could go for something totally high end such as Singxer SU-6 or Audio-GD DI-20HE interfaces. (full internal linear power supplies and high end digital clocks).

Your Project Box S2 really doesn't have any sort of good USB receiver / clocker, so I would definitely recommend a USB-to-SPDIF box for this DAC for sure.  If you did do this, I would just remove that Schiit Wyrd decrapifier because it's really not doing anything that these USB-to-SPDIF converters are already doing and it would be just another device and usb cable in the chain.

a further update...I have an Audioengine Bluetooth DAC in the basement system and discovered that it has a usb input, so I run the usb 2 from the MacAir to the Audioengine.  I hardly stream in the basement and frankly mile files streamed from my phone to the bluetooth part of the Audioengine DAC don't sound that different from the PC directly connected to the DAC, so I do either.

Ottoa63,
USB works great and is often preferred for connections of up to 10 feet.  Mahler123 is running from upstairs to his basement, so SPDIF cabling is indicated.

Ok, the proverbial dumb question,  I'm reading this post and others, my question. is it always advised to convert USB to Spdif? I'm running from Windows 10 laptop to Schiit Wyrd( decrapifier) then in Project box S2.  Will converting usb to spiff always sound better? Better in all respects. Thank you, Otto

The laptop-Dragonfly-mini cable into the analog inputs of the AVR seems to work o.k.  I had bought a mini cable from Best Buy late yesterday but then didn’t have much time for comparative listening.  I don’t use this system for streaming very much, it’s primarily for video and surround sound music.
  Searching through my pile of unused equipment I came across a Musical Fidelity VLink.  I had bought one when it came out because I had a DAC that didn’t play asynchronous USB.  If I remember it worked for a few days then would sputter during replay.  I think it was a demo unit from a dealer who was going out of business so no refund.  Ultimately I bought an Oppo 105 which had asynchronous USB

Try reset on the Node.
It worked on mine.

Or just try the $20 one short term.
You're already sacrificing SQ playing a laptop.

Why don’t you do a Roon/Pi setup with a HiFi Berry output card?

https://www.hifiberry.com/shop/boards/hifiberry-digiplus-standard-version/

I've got the vlink mentioned above.  How about $50 shipped?

You can get low cost options like a  Behringer UCA222 for part time duty. 

Schiit Eitr. Add an Acoustic Revive REM-8 to clean up the AC noise and the quality is superb

yeah, I don't want to spend more on the converter than the price of the AVR.
djones51 suggestion might work, although that is getting towards the price of buying a budget streamer.  I just wanted a quick fix to replace my Node2 in this system which is dead in the water after the last update and since I am not using this MacAir with Audirvana loaded at the moment I thought I might try to repurpose it.  There is a bargain basement convertor out there for about $20 but that can't be much good.  I have a first gen Audioquest Dragonfly that I am not using maybe I can stick an RCA cable (are they called mini cables?) that is single ended on one side and double ended on the other and attach to the analog inputs of the AVR while I try to get the Node fixed

I have a Melodius Audio MX-U8 that replaced my Musical Fidelity V-Link II.
The V-link II is 24/96.
I will sell it if you are interested for $100 usd which includes shipping to the lower 48 . Contact me if you are interested. It is actually very good sounding

This should work.
https://apos.audio/collections/brand-spotlight-matrix/products/matrix-x-spdif-2-usb-interface

The Berkeley Alpha USB and Denafrips Gaia converters are both well regarded, but probably overkill for an AVR.