As readers may know, I don't focus too much in the portable audio space unless I have a good use case for one. So when iFi offered me a chance to review the Go Blu, I almost passed That is until I realized the GO blu wasn't any AIO DAC/headamp dongle, but that it was a Bluetooth dongle. Bluetooth you might say? Yuck, bad sound quality. Actually, that's not true with today's codecs. So I went ahead to iFi's Go blu product spiel page (which I know annoys the heck out of more than a few members here) and did a ctrl-F find on "LDAC". Yup, the Go blu supports LDAC (as does my Android phone.) Before I say more, I should mention that the iFi GO blu sounds fricking great as long as we are using efficient IEMs and headphones. I tried a Sennheiser HD600 via the balanced out but presentation was one the soft side. However, I would expect the HD660S, HD560S, HD558 do do well. Personally, I been using Grados with the F pads and the Oriolus Isabellae IEMs for the past few days, obtaining excellent results. Yes, the iFi Go blu is tiny. The sound of the iFi GO reminds me of the first A&K players which used the Wolfson DA chips. This was before A&K went to Cirrus which IMO were more boring sounding in units at x4-10 the price. Despite Wolfson based DACs having the most varied sound signature compared to DAC using other chips, I've always liked the Wolfson. I've owned the AMB Gamma 2 and PS Audio Perfectwave 1 and 2. Except here's the problem: the Go blu uses a Cirrus logic. This left me puzzled, until I realized that Cirrus had purchased Wolfson many years ago. I'm betting the Cirrus chip used in this thing is based on a older Wolfson design if not recycled outright. I'll leave the rest of you to do the investigation. I have no idea what part is used in the GO blu. Back to the use case: The issue I've been having is that I don't sit around all day in one spot. I get calls, people ask my questions, I need to move audio gear for testing from one place to another, my wife comes by to ask me to do random stuff. In other words, a static desktop rig isn't doing me any favors because I have to walk away from my desk no matter if I'm at home, at a workplace, or at the local coffee shop. I was kind of looking at other folks who had wireless headphones like the Audio Technica M50 series portable, the Sony W1000xm3/4, Apple Air Pods Maximus, etc. The thing is, I really didn't want to use these headphones. I wanted to use what I wanted to use, in particular the Grados. This is because of their open design so I can hear when other people want to get my attention (including incoming dings and calls in Microsoft Teams). This is really where the iFi GO Blu comes into play.