Ifi Micro USB 3.0 impression:
I use this device with a Holo Spring KTE DAC in 3 different settings and each had a different sound:
1. MacBook (Audirvana) - Mercury 3.0 cable - Micro USB 3.0 - Gemini 3.0 cable (data and power from Micro USB 3.0) - Holo Spring KTE
In this setting the sound is very clean, detailed, good bass and trable, very good timbre of acoustic instruments but vocals are a little aggressive and abrasive on top. (I don’t have an Igalvanic to see if it could be improved with that). Overall makes the Holo sound V shaped like a forced Hi Fi sound.
2. MacBook (Audirvana) - Gemini 3.0 cable (data cable directly from MacBook and power cable from Micro USB 3.0) - Holo Spring KTE
In this setting the data signal has no treatment form Micro USB 3.0, only the power part of the USB was sent to USB module of the DAC from Micro USB 3.0
The sound with this setting is phenomena! Very natural, unforced, very clean, a realistic presentation like I never heard before. Everything is just right. It keeps the good parts from the previous setting but without the negative aspects. Now I understand why it is really important to have clean power to feed the onboard USB module of any DAC. No laptop or computer can provide this clean power.
3. MacBook (Audirvana) - Gemini 3.0 cable (data cable directly from MacBook and power cable from Micro USB 3.0) - Micro USB 3.0 - Mercury 3.0 cable (out from data together with power from Micro USB 3.0) - Holo Spring KTE
So this setting was a risky one. To feed the power from Micro USB into the same device (Micro USB) was a dangerous move but it is possible. In this way I thought I can give the Micro a clean data signal to process and filter without the Igalvanic.
The sound is more like the first setup but the midrange and vocals are more natural now. It is definitely cleaner then the second setup but in an almost unnatural way. If I want to analyze music I can listen to this setting (or for very good recordings) but to just enjoy music, I am listening to the second setup.
To conclude, my reconstruction after this experience is to buy the Gemini 3.0 and maybe the Nano USB3.0 (because it is chipper as a clean power supply) and use it as in the second setup if you like your DAC sound but want to have everything much better.
Otherwise the Ifi Micro USB 3.0 alone can be use in a setup where details need to be forced to be heard.
My other components were: Niimbus US4 headphone amp and Hifiman Susvara with Cardas Clear cable.