I was lent two trial v5i opamps to test out for my honest impressions and here they are: I used the v5i in my hattor preamp with speakers and with my lehmann headphone amp in a vinshine audio dac-r2r-ref dac/amp. Replacing the Burson V5 opamps with v5i in my opamp didn't yield much perceptible change, they share a sound signature so sounded extremely similar with the fully discrete V5 edging out the V5i in blackness of background.     Replacing the stock TI opa2134pa opamp with the v5i in my lehmann headphone amp yielded night and day dramatic...

This DAC was good enough for me to buy twice.  90% of the sound quality of a odac for cheap.  Buy it from the oregon warehouse website if you're impatient, shipping from china is slow.  New savitech usb receiver version adds support for 88.2khz and an ASIO driver which is a nice option instead of wasapi.  Haven't heard the asynchronous version but it can only be even better.  Extended highs.  Nice fast bass.  Switching to this dac got rid of noise from scrolling web pages I had when using motherboard audio.