I became aware of Apogee years ago as they make one of the more popular lines of studio Analog to digital equipment and chances are pretty good at least one of your favorite recordings was made using Apogee gear. Two things have conspired to keep me from buying their products until now. First and certainly foremost, cost. Most of the gear Apogee makes is targeted to professional studios and priced accordingly, and second most of their gear is designed for Apple and I have never been a fan of the Mac. Recently though that has started to change. More Apogee products are now Windows compatible and the Groove has come down to a price point that while still high for its class is much more attainable. I purchased the Groove without any incentives or discounts. I have no affiliation with Apogee, nor was I provided any incentives to write this review. If you have an interest in the Groove, the best deals are the bundles with Sennheiser headphones which discount the groove fairly substantially. Alternatively, refurbished models are also sometimes available via Apogee’s website.
Packaging:
Packaging is pretty uneventful. The box is black cardboard with the Apogee logo on front and the specs on the rear in silver. Inside the Groove is protected by a foam surround with the manual hidden below it along with a cloth carry bag and a USB-A to micro-usb cable. The one comment I would make is the bag is oversized for just the Groove and only a single pocket so storing the Groove and the cable together may still wind up scratching the surfaces.
Build:
The groove isn’t much bigger than a pack of chewing gum, but has substantial heft and the build is very solid. The housing is solid metal with a micro-USB port at one end and a 3.5mm female port at the other end. The underside has a rubber pad that covers most of the bottom and provides a non-slip/ non-marring surface. Two large rubber coated buttons on the surface are separated by a string of 3 LEDs. The buttons do not have a positive click to them but are not easily pushed by accident. Internally, the Groove houses an ESS Sabre dac chip and unlike most portable arrangements, the Groove uses the full desktop chip with 8 paths rather than the mobile chip that only contains 2. The Grooves uses 4 paths per channel to yield a lower noise floor and better SNR than found on the average portable 2 channel model.
Operation:
The other claim to fame for the Groove is that it is a constant current design rather than a constant voltage design that is more common in portable audio gear. (The drawback to that is the output impedance is rather high. I sent my Groove to ASR to test, and it tested very well with the exception of a 20Ω output impedance. For more details, see the measurements here.) Because of its high output impedance, the groove is best suited to being used with high impedance headphones (150Ω and up), or as a DAC into another amplifier. I had no trouble powering Sennheiser HD700, HD650s, and Beyer 990 (600Ω) models to any desired volume using the Groove. I did find that when paired with low impedance headphones such as the Campfire Cascade or Hifiman He4xx that the Groove tries to protect itself by cutting out when the volume is set too high. I also found that I could not have worn either headphone at anywhere near the volume required to cause cut-outs without causing permanent hearing loss. While not optimal for low impedance headphones or iems, the Groove still performed admirably. For sake of sound notes, I have used only the HD650s and Beyer 99os in order to eliminate any issue that might be caused by impedance mismatch.
Volume control is tied to the software volume control in Windows so you can use the buttons on the Groove or the slider in Windows to adjust volume rather than having to remember to use one or the other. Mute is only available from the Windows volume controls. The LEDs on the Groove are well designed to serve several purposes rather than cluttering up the device with more stuff. A single blue LED means power is on, but no signal is being recieved. When a signal is received, all three LEDs are used to show the digital signal input level. A single Green LED mean -20 to -30 dB, two green LEDs mean -4 to -10 dB, and all three LEDS lit green means >= -3bB. If clipping occurs, the top LED will go from green to red to indicate it. When volume levels are changed, the LEDs light purple to indicate the direction and amount of change
Interestingly, I found that the Groove continues to be powered even when the PC sleeps and draws roughly 1.6 Watts of power the entire time it is plugged in. This causes the Groove to be very warm to the touch after use but never particularly hot even after long listening sessions. I also found little or no difference in heat after 45 minutes of listening to the 990s vs the same length of listening time using the HD700s so impedance does not seem to contribute to heat production as it does on some other designs. (Granted this test was entirely unscientific and was just it doesn’t feel notably hotter so some minor differences may be lost to method here.)
Sound:
Reviewing the sound of a DAC amp is a difficult proposition as in a perfect world, it shouldn’t have one. The Groove does not make that job any easier as it does a good job of not adding anything to the music. I did notice a very slight warming of the sound when paired with the Cascade but think this may be more due to the impedance mismatch than anything else. The Groove does show some characteristics of its SABRE implementation as it leans toward the analytical with a slightly cold sound as a result.
Comparisons:
I pulled out several other portable DAC/Amp combinations to compare to the Groove. Amongst them were the Fiio E07K and E17K, Sabaj Da3, smsl idea, ifi xDSD and nano BL. The Groove easily outclasses the Fiio, Sabaj, and SMSL idea when comparing output power but is clearly aimed at a different target market. Were I to be pairing the device to high sensitivity low impedance in-ears, I would go with the Sabaj or SMSL. When powering anything over 150Ω both the Sabaj and SMSL are very limited and cannot provide enough power to really open up more power hungry cans. The Groove on the other hand had no trouble pushing 600Ω Beyers to volumes that would cause hearing loss.
When compared to the xDSD or nano BL, we have a closer fight. The Groove provides nearly the same amount of power as the other two but lacks the filter options and is not battery powered as the Ifi products are. The Ifi products are both bulky when compared to the Groove and while the xDSD and Groove both have LEDs to show volume range, the Groove is a bit more intuitive as it takes a bit to memorize the color patterns used by the xDSD.
When used purely as a DAC paired to my Valhalla amp, the Groove offers performance similar to the Bifrost or Khadas Tone Board I usually use for this.
Conclusions:
Some will immediately read the comparisons and draw the conclusion that the xDSD is a better device. I think that depends on how you intend to use the device. As a dac, both are very good and offer similar performance. As an amp the xDSD is more capable with lower impedance devices while the Groove really starts to show its muscle with 300Ω and above models. The xDSD was designed to be paired with a smartphone for on-the go use while the Groove was designed to pair with a laptop (either Windows or Mac) and used while working. For those who want a simple device that works well and provides all the power they need for studio headphones, the Groove does a very good job. It doesn’t offer a lot of options, but it is plug and go. No fiddling with lots of drivers, settings, or software, just plug it in to an available USB port and plug in your headphones. Most will try to compare the Groove to portable DAC/Amps because of its form factor and this leads to the assumption that the Groove is not price competitive. When instead compared to other desktop combos like the Magni 3/Modi 2 Uber, you have similar price and performance in a more convenient form factor.
