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

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. 

@mikhailark Don’t worry. The disagreement originates from misunderstanding.  The factory PS for micro DAC is indeed SMPS, a good low noise one. However, the micro DAC takes 15V 2A and you could throw in 15V, min. 30VA LPS to power it.  A good LPS with low ripple noise at both empty and full loads ranges from $120 (like LHY) to a few hundreds.  Soundnews actually tests both options and find the factory SMPS is ’good enough’.

One other space-saving aspect of the micro DAC is that it only comes with XLR output.  Also, according to a reliable source, the dual beefy transformers in the Denafrips Pontus account for roughly 24%–32% of its total weight. After subtracting those, along with associated components and the chassis weight that would no longer be needed with an external power supply, I’m afraid what remains might be roughly equivalent to the Harmony DAC.

The small form factor offers necessary space savings for some users, and as long as it doesn’t compromise quality, I’m more than willing to accept it. However, to claim that the physical size of a device directly impacts its sonic quality — I just haven’t seen any evidence to support that. So for now, I’ll sit tight and wait for the next reliable review I’ve been looking forward to.

@lanx0003 So, I decided to try the direct USB connection between my streamer and dac eliminating the DDC.  It still sounds really good, but I do notice a little bit less detail and clarity.  Like you said, that could be the DDC, or it could be that my dac is optimized for I2S.  I have no way to test it because my Innuos only has USB outputs.  

Anyway, I'll leave the DDC in the chain.  

Thank you for the feedback, @sls883.  Have you also used 10Mhz clock into U18?