Just about to pull the trigger on Pontus 15th ...

I’m using a Gustard U18 DDC between my Innuos streamer and dac.  It converts USB to I2S.  I checked with Gustard and Innuos about using the U18 or skipping it and going USB directly from the streamer to my dac.  Both Gustard and Innuos recommended using the DDC, so I never tried it without the U18.  I already had the U18, so I’m using it.

I’ll probably try going USB direct from my streamer to my dac to see if I hear any difference.  I really thought that Gustard or Innuos would suggest skipping the U18. 

It would be useful information to know. However, you wouldn’t be able to tell whether any difference comes from the DDC, the I²S connection, or the combination of both. I recall there were some ‘serious’ discussions on this topic a while ago.  The topic gets even more convoluted once you bring the 'clock' into the picture.

@lanx0003 - "These days, as you know, it’s actually quite hard to find a bad or even mediocre DAC at any price point". Oh yes, you can . Thing is, any DAC has analog parts. There is a price limit on quality capacitors, power supply and sufficient space to isolate, shield and ground components. Plus, each chip and technology calls for different analog parts (filters, etc) so they WILL sound different. This, of course, does not mean that $$$$ is always better than $$, but there is a limit. Always check engineering and photos of unit internals.

Yes, price does not play the music.  And I concur with what you have just said. That’s why I showcased the internals of this micro DAC from the start, including 0.05% precision/tolerance resistor packs, galvanic isolation (between analog and digital), a femto clock, and a discrete Class A output stage that provides low output impedance for better matching.

One way they managed to fit all those quality components into such a small chassis was by placing the power supply externally. In contrast, several bulky and heavy DACs, like the Denafrips Pontus, have multiple transformers built in and shielded internally.  There are pros and cons of doing either way...

@lanx0003 - "we are in a violent agreement"  I do have a little distrust for small form factors from engineering perspective. Placing power supply externally is a good thing, BUT in 90% this will be a switching PS wall wart. This means noise may and will come over the low voltage wire. Second issue is that external simple PS brings a single voltage. This limits circuit design since some may call for multiple power voltages while being isolated. This is why external PS in $$$$ equipment use proprietary connectors since they carry multiple voltages. So Denafrips most probably uses multiple different voltages isolated from each other. This give more freedom to the the circuit designer BUT also calls for better shielding and larger form factor.

Disclosure: I own Terminator 12th with Iris DDC.