I have to be honest, while I had seen the promotional photos with various items providing scale, I laughed out loud when I first opened the GO blu box to reveal the Bluetooth DAC/Amp in all of its diminutive splendor. Pictures can’t prepare you for how small this thing is. This isn’t a model of a DAC/Amp for ants. No, it will fit perfectly in any ant-sized personal audio or home entertainment stack. In short: it’s small. But can it do big things with its small stature?
Build and Design
You may have gathered this from my opening paragraph, but GO blu is not very big. The official dimensions are 2.2" x 1.3" x 0.5”, which means that my thumb is both longer and thicker (though not quite as wide) as this particular all in one Bluetooth receiver, DAC, and Amp. It features a very well executed volume knob, with a design inspired by Swiss chronographs, and three total buttons serving various functions. In terms of things you can plug various wires into, there’s also a USB-C charging port, a 3.5mm single-ended output and a 4.4mm balanced output.
GO Blu is also very lightweight, but seems to be quite solidly built. It’s so light, that when I had my headphones plugged in, it would frequently fall off my desk – dragged down by the weight of my headphone cable. There’s a nice feel to the overall fit and finish to the device. The front features a plastic faceplate with a copper-like look to it, while the rest of the device has a rubber coating which provides a nice grip with a feeling of greater quality than hard molded plastic would have.
Interface and Features
As mentioned above, most of your interaction with GO blu comes from three buttons and the volume knob. The volume knob works to control the volume on your phone or other connected device and is not an independent volume control for the GO blu itself. There appears to be some level of intelligence to the volume control based on the outgoing impedance, as the volume control felt just as smooth with sensitive IEMs as it did with over-ear headphones with a much higher impedance.
On the side of the volume knob, you have a playback control button, which can be used to pause, play, skip tracks etc, depending on how many times (or how quickly) you press on the buttons. On the right side of the unit, below the volume knob, you have the button which controls both sound filters and Bluetooth pairing. Short presses on the button cycle between standard, XBass, XSpace, and XBass + XSpace. A long press activates Bluetooth pairing mode.
Other than the soothing voice which alerts you that the headphones are on, pairing, connected, etc. the only direct feedback you get from the device is an LED which changes color based on the active sound filters or blinks during the pairing process. Like many devices of this sort, there’s a factory reset button on the bottom side of GO blu. You’ll need to use a pin or similar tool to press and hold the button to trigger it.
The pairing process was quick and painless with the devices we had around the office, including an iPhone XS, a Samsung S21 Galaxy Ultra, and an Astell&Kern KANN Alpha. I would say that GO blu has a simple “plug and play” setup, but I guess it’s “don’t plug, but still play.”
Sound and Performance
GO blu not only exceeded my expectations in how small it could possibly be, it also exceeded my expectations in its sound quality and output. In GO blu, iFi delivers sound quality that’s in a class with its classic ZEN DAC desktop DAC – with a similar generally neutral sound with a touch of warmth – in a form factor that can fit, not just in your pocket, but in that tiny fifth pocket in your jeans.
The power output isn’t anything to write home about, maxing out at 5.6V in balanced mode, but it should be enough to drive any number of typical over ear headphones, and, of course, just about any IEMs. In my testing, I used Meze 99 Classics, HIFIMAN HE400se, and then pulled out the Meze Elite just for fun.
I found the IEM performance to be pretty consistent. There was no audible hiss with anything I tested, good detail for a mobile device at this price point, and a balanced to slightly warm output. With an IEM like the 64 Audio U6t, GO blu does a good job of bringing out the deep bass response, while on the flipside with the 64 Audio Nio or Noble Tux 5, the bass doesn’t become overpowering or bleed into the mids.
The 99 Classics can’t handle too much additional warmth without getting muddy, and GO blu managed to not cross that line, though the treble ends up feeling a little light. The HE400se was the headphone I was most impressed with. On low power sources, it tends to have good detail, but sound thin and bright. GO blu provided a balanced sound, turning on XBass really brought the low end alive with a good bit of slam, and XSpace provided the needed support for the soundstage.
There are probably not a lot of situations where you want to listen to $4000 open-back headphones on a $199 Bluetooth DAC/Amp. If you do run into one of those situations, GO blu does pretty well. There was good low end presence and some slam, and while the detail wasn’t anywhere near the level of detail Elite is capable of delivering, it would work for casual background listening – like something to sneak away with on a busy family vacation. The overall balance was warm, but there were some feelings of harshness in the upper registers on Elite, especially with the percussion and cymbals. Again, probably not a top choice for pairing, but considering Elite is 20x the price of GO blu, GO blu holds up quite well.
The Bottom Line
While Bluetooth tech has yet to catch up with USB or WiFi as a truly lossless delivery system for music, for times when convenience is king, Bluetooth 5.1 helps deliver that convenience with higher fidelity than ever before. GO blu delivers extreme portability, along with performance that sacrifices very little fidelity for your convenience.