To DDC or not to DDC. That is the question.

I use Galvanic isolation and DDC  each one  paired with Buffer/filters and each one powered by LPS.

I used my ears to decide to upgrade or  not my optimization process ...

Everything cost peanuts (from China) 

 Each time was improvement ....

@jacupmakeup 

I also use 2 DDC's between my streamer and DAC as it is better than direct USB.  I think the clock in the DDC does not have to be better than the DAC's for the DDC to provide benefit.  Just avoiding USB noise can have enough benefits that an inferior clock can still benefit the DAC's performance.

@rikkipuu yep I believe you are correct

If you are using a computer as your streamer, I think a DDC will almost always help.

If you are using a dedicated audiophile streamer, it's very hit or miss.  

I contacted Merason directly and the DAC designer and founder of Merason responded. The DAC1 is built with the USB input optimized and he does not believe that an additional DDC would be of benefit unless I was using coax or AES/EBU. I’m using an Eversolo A6 with Beatechnik LPS as streamer.