Pros: Great DAC, able to drive IEMs and most low impedance headphones
Cons: 96kHz limit, not able to drive high impedance headphones very efficiently
Focusrite may not be a familiar name in the Headphone Audiophile community. Many might be more familiar with Creative Labs, Turtle Beach, ASUS, etc. as makers of "entry level" headphone gear, but for those who don't know, Focusrite is a very familiar name in Professional Audio. Focusrite's claim to fame comes from their microphone preamps, which for decades have been found in many commercial recording studios.
Why does this matter to the average Headphone Audiophile? Well, for starters they have experience in Pro Audio and understand that having a good DAC is essential to making critical decisions while working on audio, and so they put a Cirrus Logic 4272 chip in this unit (this is the same chip used on other portable pro audio boxes made by Avid, Apogee, etc.) They also designed this box to be used on-the-go, so a decent headphone amplifier would be important, as many musicians track and mix their songs with headphones. The 4272 chip is well-designed, low cost and does ADC/DAC simultaneously. In my opinion, the unit is worth the cost for just the quality of recordings you can get from it; in addition to the good ADC/DAC chip, you have two excellent, recording studio quality microphone and line preamps (your recordings are likely to sound better than using anything made by the other manufacturers that don't have a pro audio pedigree). The box features low-latency monitoring so you are able to monitor your recordings without having the signal go through your computer's processor first, which would add a lot more delay to the monitored signal; in essence, it is a very decent recording solution for those who might want to record analog sources and convert them to digital formats on-the-go. This all benefits the Headphone Audiophile, who would value having a box with a good DAC chip and clean headphone stage.
How does it perform as a portable DAC and Headphone amp? Well, as someone who primarily listens to high resolution audio through a mastering-grade DAC, here are some of my real world observations on this unit:
Installation was a breeze. I have read many negative comments online regarding their drivers, but these tend to go back to 2012 when the unit was initially released. Two years later, I can only assume that they fixed a lot of those issues because I had no problems downloading and installing the current drivers on a Win7 Lenovo laptop that I use with the unit. Once the drivers were installed, I set the Scarlet as the default audio device and then plugged it into a USB port using the included cable, immediately a green light went on the unit.
As a DAC, I found the quality to be very clean. I've got tons of listening experience with various DACs, ranging from bad to good and a lot of the good qualities I'm used to from good DACs are found here. No noise, a wide sound stage; the DAC is very accurate. The only negative here is that the unit's sample rate tops at 96kHz, which is fine for most audiophiles but it's interesting since the Cirrus Logic chip used here supports up to 192kHz sampling rate (perhaps it's a limitation on this box due to the unit being USB-powered). The 1/4" analog output stage of this box is also very clean and I also use the scarlet's analog outputs to connect to my HiFi receiver whenever I want to play music from my cloud over my home HiFi system, and it sounds great. Here are my comments on the headphone amp alone (which unfortunately isn't as amazing as everything else on this box):
I played back some audio from the cloud (Google music library) and listened to the following IEMs/Headphones: Samsung Galaxy 5 earbuds (which are very good for OEM earbuds), Klipsch S4A, Grado SR80i, and my Beyerdynamic DT770 Pro (80 ohms). The headphone amp is able to drive the IEMs without any problems, and it handled the Grados really well (although I found the quality to be a bit grainy as I pushed the level up a bit higher than my normal listening levels). I was able to drive my Beyer 770s fine as well, but again, the sound was a bit grainy as I pushed the levels up past a nominal level; with higher quality amps, you usually hear a well-defined, non-distorted signal (that simply becomes too loud to handle). It seems the headphone amp in the unit is clean, but past nominal levels with low impedance headphones and IEMs, the quality starts to suffer; the audio starts to distort a bit (I didn't even bother trying my Sennheiser 650s on it).
I don't think that this box beats a dedicated high-end DAC + Headphone Amp combo, but for about $150, this can be a good purchase for those who also want a portable, very decent quality recording solution on top of having a good DAC and clean (although a bit underpowered) headphone amp to drive low impedance cans on-the-go.