I bought a used Denafrips Iris and have had no problems whatsoever nor have I heard of anyone having issues with their DDCs, and the Singxer SU6 is maybe even a little better and have seen no issues with that unit either.  Not sure what you’ve been reading, but I wouldn’t hesitate to buy another ChiFi DDC. 

I use a Mutec MC3+USB    It’s a reclocker and converts inputs to Coax , TOS, or AES.  It does a great job of converting USB to Coax. 

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.

Regarding reliability with ChiFi, I have a Gustard x20 pro. The display has paritally failed. I also read some threads online about similar display failures in their headphone amps or preamps, and in the case of a headphone amp, a failure of the volume control relays.

I bought a used Iris12th from Denafrips repair center and it failed, maybe it was a faulty unit that was sent in for failure, repaired and failed again, sent it back. Bought a used one off USAM and it did fine, sold it still playing with no issues. 

@magon 

"Regarding reliability with ChiFi, I have a Gustard x20 pro. The display has paritally failed. I also read some threads online about similar display failures in their headphone amps or preamps, and in the case of a headphone amp, a failure of the volume control relays."

So, because Gustard has quality issues, you feel free to paint all Chinese products with that brush? Sounds like you have an issue with China.

@tony1954 Whoa, you're projecting. I'm bringing up a concern that I've encountered all over the forums. If it's not reality, then it's not.

@mitch2 Thanks, the Holo Red looks interesting.

While the MC3+USB isn’t cheap, it’s made in Germany.   For owners of R2R DACs that can only do 24/192 it will accept up to DSD256 and sample rate convert to 24/192.  It can also simultaneously output across all outputs with each digital input. Let’s say you have two sources plugged in one via USB and one via Coax.  If you select the USB you will get output on TOS, coax 1, coax2 aes 1v pp, and AES.  If you aren’t using USB inputs , it can output via USB to your PC and any Coax or TOS , AES input will appear as USB out.  
 

Also if you have an input that you want to sent to two DACs at the same time you can.  Your primary and a headphone / DAC.    It has a lot of cool features, it has an internal clock , can be a word clock and has a 10m input that I use with it and my CD transport.  

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.

@mitch2 

You're missing out on a lot if you're limiting yourself to SPDIF.

What front end and DAC do you have?

@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.

@magon 

The internet is full of "opinions".

We, as individuals, choose which ones we believe and whether we promote them.

I've never had an issue with either Singxer or present Denafrips Gaia DDC, and for that matter any Chifi audio component. Based on my experience, China and Asia in general offer major bang for the buck digital and streaming components, and they can also play the game at the much higher end of these components.

@mitch2 

I think the best solution for you is the Denafrips Gaia https://www.denafrips.com/gaia

If you go with the Mutec MC3+ USB to get the best out of it you will need to attach a 10Mhz master clock, the internal clock is trash.

Cybershaft in Japan make great clocks, no need to spend more.

Of the thousands of ChiFi DDCs sold this is the first post I’ve seen here about any units failing, which is a pretty strong indication there is no widespread issue with these products or we’d undoubtedly be hearing a lot more about it.  I’ll also say Gustard in particular has had reliability issues in the past so may not the best indicator of overall ChiFi product reliability.  So avoid these DDCs if you want, but it does not seem justified by the overwhelmingly positive experiences and comments made by people here. 

On a good dac or streamer dac combo, the equivalent of ddc function should already be built in. It should happen right before the conversion with negligible signal travel, etc.

You could screw it up when you have a separate ddc box to do such things, run a wire from it and so on..

@tony1954 

Bye.

@deep_333

The main issue is that I have a DAC with only S/PDIF in. No USB.

I also have a DAC with USB in and I probably wouldn't use the DDC with that.

Bel Canto Design – REF Link USB Converter