DDC Sound Improvements???

Yes, I would look into the LHY models. Alvin should be helpful in leading you on that decision. I honestly don't know much about master clocks other than getting the best OCXO you can afford. Denafrips makes a couple master clocks too. 

I don’t why I didn’t think of looking at the GUSTARD brand? As you introduced me to that brand.

lhy makes good stuff, excellent quality of parts and assembly, alvin is very responsive and a nice guy to boot

paul pang (taiwan) and afterdark (in hong kong) also make excellent, cost effective standalone ocxo word clocks, with 50 or 75 ohm outputs

with my ether regen, adding a strong clock on the clean side unit made a substantial difference in sound quality, as much as i did not want to believe that would be the case before trying it

I'm using an Innuos Zen MKiii streamer with a Gustard U18 ddc and a Gustard X-30 dac.  I'm also using a LHY ock-2 clock which is connected to both the U18 and X-30.  I've tried both sine wave and square wave.  I prefer square wave in my system.  The LHY clock definitely made an improvement. 

I've connected the U18 to my dac via i2S and coax.  With a good coax cable (Black Cat Silverstar 75), I hear little difference between i2S and coax.  I couldn't say which one is better.

When I got my X-30, I reached out to both Gustard and Innuos to see if they thought that I should connect the streamer to the dac via USB and eliminate the DDC.  They both suggested that I continue to use the DDC. 

The U-18 works quite well.  I doubt that I would see much improvement, if any, by going to the U-26.  I've posed this question to Gustard and haven't gotten a response. 

@stillbuyingtoys 

$1,000 for a DDC vs $4,000 for a transport is pretty tempting.  In my head this additional filtering in the DDC would give me the sonic improvements of a great streaming transport.

What are your thoughts and experience?  

I play 100% of my digital files, directly from my laptop (no internet).  Using a good Audioquest USB cable, and it sounded very good.  But I have heard better, with the same DAC, using its CD transport.

My solution was to have my laptop feed a Berkeley Audodesign Alpha USB Series 2 re-clocker, and have that re-clocker feed my DAC via AES/EBU.  It sounds amazing.

But the price exceeds your $4,000 price that you mentioned, mostly due to the USB cable and the AES/EBU cable.

The Berkeley re-clocker was $2,245.50 (they have a reference model that is twice that price).

I can't say how important the role of quality cables are, for connecting that re-clocker.  I purchased very good ones, and have no other cables to make a swap for comparison.

That Berkeley re-clocker lowers the noise floor, and reduces jitter, and the results are impressive.

Note that that re-clocker has only one input option: USB.

And it has only two output options: SPDIF and AES/EBU.  Berkeley recommends using the AES/EBU option.

Be careful of USB cable lengths.  Try to keep it short.  AES/EBU can be much longer, without being a problem -- although, Shunyata Research recommends keeping their AES/EBU cable at 1.5 meters.  I needed a longer one, at 2.5 meters, and it sounds great (but would I hear a difference if it was 1.5 meters?).

From reviews, that Berkeley re-clocker makes any streamer / DAC combination sound better.  But I can't speak on such usage, because I use mine with locally stored wav and flac files.  But if I had to make a wager, I would confidently say that that Berkeley re-clocker would do wonders for your streaming.