reliable DDC

A lot of DDCs are manufactured in China, although dcs makes one that is manufactured in England.  The Berkeley Alpha USB is manufactured in USA and there are probably more. 

The Singxer SU6 measures well and has worked well for me.  It is not in my system now since the two DACs I currently have are optimized by the USB input. I also owned a Gaia that worked.  If I were buying new, I would look at the Holo Red, which measures well and is also a streamer.

Here is a USB to S/PDIF converter for sale that was made in USA.  The Sonicweld Diverter (link) was well-regarded for sonics.  Here (link2) is some general info and if you do a web search, you will find several reviews.

@lordmelton 

I am not using the DDC currently.  Both my current DACs, Mojo Audio Mystique X SE with Lundahl nano-crystalline chokes and AD-1862Z chips, and an Aries Cerat Helene, sound best through their USB input so that I what I am using.

The USB comes out of a Sonore Signature Rendu SE Deluxe optical that is connected to a SGC sonicTransporter i9 via A fiber optic cable.

I reinstalled my Singxer SU6 DDC the other day so that I could utilize the two S/PDIF outputs at the same time to make my comparisons between DACs in my system easier and quicker.  

Even though the two main DACs I have here are both said to perform best from their USB connections, my initial impression is that feeding them a signal via S/PDIF through the DDC sounds as good as through a direct USB connection.

BTW, to the OP’S question, the SU6 has been totally reliable every time I have used it in my system with no glitches whatsoever, unlike the Denafrips Hermes I previously owned which didn’t want to cooperate with my other digital gear at the time.