Computer audio advances rapidly. Shortly after I reviewed LH Labs’ Geek Out 450 amplifier/DAC (Issue 251), an improved version appeared. Named the Geek Out V2, the new model offers some interesting improvements on the original Geek Outs. If you’re wondering what a Geek Out is, well, it’s a combination DAC and headphone amplifier built into a very small (1.48″ x 0.51″ x 3.07″), light (1.2 oz.) package. As was the case with the original, power for the V2 comes from a USB port on a computer, which is also the only signal input for the V2. There are several different models of the Geek Out V2; this review deals with the basic one, which sells for $299. There’s also a larger V2+ model that includes a battery and uses a smartphone as a source instead of a computer.
The Geek Out V2 is functionally similar to the Geek Out 1000; both amplifiers can produce 1000 milliwatts (that’s a whole watt) into 16 ohms. A 1000mW power output will comfortably drive most headphones on the market today. The V2 also has a setting that resembles the Geek Out IEM 100 USB DAC and headphone amplifier that produces 100mW into 16 ohms. “Why,” you might wonder, “would I want an amplifier that produces so little power if it also produces ten times as much?” The answer is that a lot of in-ear monitors, a.k.a. earbuds, require very little power, but need a very quiet source, which is what the 100mW setting of the V2 offers. A button on the side of the V2 switches between power settings. It’s audibly obvious which setting has been selected, but there’s also an LED to let you know.
The original series of Geek Out DAC/headphone amplifiers was housed in an aluminum chassis that got surprisingly hot, thanks to the use of a Class A headphone amp and the fact that the case was not ventilated. Class A amplifiers produce top-notch sound, but run very warm. The Geek Out 450 wouldn’t burn you, but it would surprise you when you grasped it. One of the V2’s major upgrades is that it’s housed in a case manufactured on a 3-D printer and has lots of heatsinks and vents to dissipate the heat from its toasty Class A amplifier. In another improvement, the amplifier parts are better distributed on the tiny printed circuit board inside the case, which also promotes heat dissipation. The case is made of high-temperature resin.
It’s just my opinion, but to me, the V2’s case, decorated with interesting scrollwork, looks much more elegant than that of the original Geek Out. This was the first item I’d seen that was created by a 3-D printer, and I was surprised to see how intricate the design and execution were. I expected the case to be larger than that of the original Geek Out, but it was approximately the same size. The V2 did not come with a USB dongle extension cable, and the original did. That dongle was very handy for a couple of reasons: 1) it didn’t put as much strain on the computer’s USB connector as plugging the V2 directly in did; and 2) if you plugged the USB connector directly into the computer (without the dongle), it would block adjacent USB ports. LH Labs offers USB dongles at extra cost, or you can use any cable with a male Type A USB plug on the origin end and a female Type A plug on the destination end.
The V2’s DAC chip is an ESS SABRE9018AQ2M DAC (an upgrade over the 9018K2M in the previous version), and it’s pretty impressive: It plays PCM files up to 384kHz/32-bit and DSD files via DSD-over-PCM (DoP) up to DSD128. Although a few DSD256 albums are beginning to be released, their number is limited so far, so the V2’s inability to play them isn’t a serious problem—yet. The V2 offers two filter settings, explained in the manual as follows: “TCM (Time Coherence Mode) uses LH Labs minimum-phase digital filter and time-optimization algorithm, which removes all pre-ringing from the converted signal and realigns the impulse response, [presenting] the listener with a more well-defined and natural soundstage; FRM (Frequency Response Mode) uses a slow roll-off digital filter and frequency-domain-optimization algorithm to provide a smoother and clearer sound with even lower THD+N in the high frequencies.”
The button on the side of the V2 furthest from the USB connector switches between the two settings, with a colored LED indicating which is selected. This button, plus the one for the power setting, are the only physical controls on the V2. The manual says a green LED indicates the FRM filter, while a red LED indicates the TCM filter. However, the two LEDs on the review sample were green and blue. Volume is a 64-bit digital arrangement controlled by the computer. I had some problems with the original Geek Out 450’s volume control, which I later discovered were peculiar to the computer I was using, but the V2’s volume control operated just as advertised.
LEDs on the side of the V2 show the sampling rate of the files being played. You have to look carefully to see the labels printed on the V2, because the LED colors don’t tell you the precise sampling rate. The LEDs indicate the following: 88.2/96kHz (white), 176.4/192kHz (white), 352.8/384kHz (white), DSD64 (blue), and DSD128 (blue and white). If music is playing but none of the sampling-rate LEDs is lit, that means you’re playing a 44.1 or 48kHz file.
The V2’s circuitry is fully balanced. A second headphone jack, which comes with a plug inserted, makes it possible to connect balanced headphones or connect the V2 in balanced mode to your amplifier using TRS-to-XLR adaptor cables. Output impedance is 0.47 ohms, which should be sufficiently low enough to drive any headphones or earphones you might want to use, no matter their impedance.
The V2 plays PCM files up to DXD level (384kHz/32-bit) and DSD128. LH Labs believes it will be able to upgrade the firmware to play Meridian’s Master Quality Authenticated (MQA) files in the future, which is something you should look into before buying any DAC. As of late July 2015, I haven’t personally heard any MQA-encoded recordings, but every report I’ve seen about MQA gives a glowing account of its sonics.
Setting Up and Using the Geek Out V2
The V2 shipped in a standard U.S. Priority Mail carton double-packed with a second box. When I unpacked it, I found a user manual printed in four-point type, which even my strongest reading glasses plus a magnifying glass couldn’t decipher. Fortunately, there’s a readable version on the LH Labs website. Since I use a Windows computer, I needed to download and install a driver; Macintosh and Linux computers don’t require that annoying chore. However, LH Labs provides instructions for the installation, so the process was routine. After the driver was installed, I checked the Windows Sound settings in the Control Panel to be sure the LH Labs V2 was identified as the default sound system, and changed the Audio Device setting in J. River Media Center Version 20 to select the LH Labs Geek Out V2 [WASAPI] driver. Then I selected a song in J. River, clicked Play, and enjoyed a rich, detailed sound right out of the box.
I used my desktop computer, an ancient (in computer years) Dell Inspiron 530 as the source, borrowed the dongle from my Geek Out 450 to connect the V2, and used a variety of headphones, including NAD Viso HP50, Audeze LCD-X, and AKG K712 headphones. I also used some Sony SBA-H1 earphones to try out the V2’s low-power settings. On most pieces, the low-power setting drove the Sony earphones, the NAD Viso HP50 headphones, and even the Audeze LCD-X headphones as loudly as I wanted; on a few recordings, made at a very low level, I preferred to switch to the high-power setting. Fortunately, the high-power setting was plenty quiet with the more sensitive headphones/earphones. The high-power setting was sufficient for all the headphones at my disposal, although none of them is a real power-hog. To be sure I got the measure of the V2 with different cans, I used two considerably different headphones—both of which are pretty sensitive, low-impedance designs that don’t require a lot of power: the Audeze LCD-X, an open-back planar-magnetic design which sells for $1699, and the NAD Viso HP50, a conventional voice-coil closed-back design that sells for $299.
I experimented with the V2’s filter settings. The differences were subtle, and somewhat dependent on the music played. Thank goodness there were only two filter settings; I’ve seen DACs that offered as many as seven. That’s a cruel thing to do to a poor audiophile trying to find the best sound. And the V2 really did run considerably cooler than the Geek Out 450; it was very comfortable to touch.
With all music I played through it, the V2 produced a wide-open soundfield that was more spacious than I expected from headphones. Some headphone amps make everything sound like it’s coming from the middle of your head—but not the V2.
Classical music conductors and composers seem to have fun taking pieces from various operas by late baroque French composer Jean-Phillipe Rameau and recombining them into new works. In heavy rotation at Casa Forrester recently has been the album Le Grand Théâtre de l’amour (96kHz/24-bit AIFF, Erato/HDtracks), which is precisely such a work, performed by soprano Sabine Devieilhe and assorted other singers, accompanied by Les Ambassadeurs under the direction of Alexis Kossenko. Through the Audeze headphones this album was presented with a big sound—big in several respects. Dynamic range was big, from the opening piece with lots of percussion; the soundstage was big, spanning from ear to ear; frequency range was big (wide), from powerfully impressive deep bass to the highest notes in the sound effects of the track “Les Indes Galantes” (“Vaste empire des mers”). There was plenty of detail evident in both voices and instruments. The performance was energetic and spirited, and the V2’s quickness accurately reproduced this re-composed album as though it had actually been written by Rameau. Through the NAD headphones I got similar sound—wide, though more diffuse soundstaging, surprisingly good bass, but lacking the fine detail afforded by the Audezes.
Another new album I’m really enjoying is James Horner’s Pas de Deux (96/24 AIFF, Mercury Classics/HDtracks), a double concerto for violin and cello. Yes, that’s the same James Horner who wrote the soundtrack for Titanic, who tragically died in a plane crash in June 2015. A serene, peaceful, and ravishingly beautiful work couched in Horner’s familiar musical vocabulary, Pas de Deux demonstrates how well movie soundtrack composers can do if they turn their efforts to serious “classical” compositions. Pas de Deux is a useful listening tool because its subtlety can be challenging to reproduce accurately. A well-known DAC costing nearly $2000, currently under review, makes it a little hard to identify what instruments in Pas de Deux are being played. Through that DAC, harmonics don’t seem to coalesce into the sound of real musical instruments. That’s not a problem with the V2. Through the Audeze headphones, the violin and cello were distinctly and realistically depicted, as are the other orchestral instruments. I might add that in this piece, the difference between the Audeze and NAD headphones was quite distinct. The Audezes produced quite vivid portrayals of the solo instruments, with harmonics that were just flaming gorgeous, while through the NAD the instruments sounded a bit more generalized. If the notion of using a $299 DAC/amplifier to drive $1699 headphones seems goofy, the results make complete sense. The V2 is not embarrassed to be in such expensive company. Reproduction was unstrained and effortless. (I have discovered one drawback to using this album for critical listening: it’s awfully hard to turn it off. Check it out on Tidal with the “HiFi” setting, or on your favorite streaming site.)
On the über-familiar La Folia 1490-1701 by Jordi Savall and his band (44.1/16 AIFF, ripped from Alia Vox AFA 9805), the track “Folia Rodrigo Martinez” was reproduced through the Audeze headphones with copious detail, not peaky or etched sounding, just tons of rich musical detail that let me hear more of what’s on this recording than I normally do. The bass drum, which descends into the mid-20Hz range, seemed slightly rolled off, so I didn’t hear the deepest notes present on this recording. All other instruments sounded whole and realistic, and were not temporally smeared. Dynamics were forceful without being overdone. Percussion instruments clattered energetically, with well-defined leading-edge transients. It was a splendid rendition. The NAD headphones did essentially as well, with perhaps even more emphasis on the leading-edge transients, though they still weren’t overly emphasized.
So how did the V2 handle voice? Out came Lyn Stanley’s Potions [from the 50’s] (DSD128 DSF, Downloads NOW!). Through the Audeze headphone, the V2 revealed every nuance of Stanley’s performance of these jazz standards. Bass was deep and powerful. The V2’s precise pace reproduced Stanley’s pinpoint timing, which is a major contributor to her expressive phrasing. Transients were quite realistic—neither too sharp nor too slow. The NAD headphones were a smidgen less smooth but nonetheless very listenable.
My litmus test for soundstaging is the track “Miserere” from The Tallis Scholars’ Allegri’s Miserere & Palestrina’s Missa Papae Marcelli (96/24 FLAC, Gimell). A commonly held belief is that headphones can’t possibly reproduce the spatial aspects of recordings since they are just transducers clamped to the sides of your head, with no chance to detect the ear-to-ear crossfeed that is believed to be the reason we hear soundstages with left and right speakers. However, the V2/Audeze combination blew me away by reproducing a credible version of the entire soundstage of the recording venue, a church. The solo group that’s separated some distance behind the main group upfront was distinctly placed in the rear. Institutional wisdom says that can’t happen—but it did. OK, I’ve heard better soundstage reproduction from some loudspeakers—some, not all. The NAD headphones also produced a wide soundstage, but sounded a little less smooth, grainier. Another way of describing the difference would be that the Audeze headphones had a purer, more natural sound—which is pretty much how they sound through any amplifier.
Given their intrinsic sonic differences, the V2’s presentation through these two headphones was essentially the same. Both sounded outstanding. Through the Audeze LCD-X, the Geek Out V2 was mesmerizing. Whoever says you shouldn’t use a $299 DAC/amplifier with megabuck headphones hasn’t heard them with the Geek Out V2.
For the comparison, I’ll use only on the Audeze headphones, since they provided more information than the NADs—which you’d expect, considering the price differential. I’ll make my job harder by using the Geek Out 450—the original Geek Out—for the comparison. These two units had a lot in common sonically—not surprising, I suppose—so distinguishing between them was a real challenge. However, I was game to try.
On “Miserere,” the 450 also threw a huge soundstage, but the solo group in the distance sounded slightly less well-defined and more mechanical, i.e., less natural. The 450 came close to the V2, however; in fact, I had to don my über-picky reviewer’s hat to distinguish between the two.
“Vaste empire des mers” made for a very close call between the two Geek Outs, but the V2 seemed slightly more open.
On Pas de Deux, I thought the solo violin and cello were more distinct with the V2. I could hear a bit more about the individual instruments—with more precise harmonic definition.
“Folia Rodrigo Martinez” showed several differences: for example, the V2 made the castanets clattering in the background more distinct. This was partly because it portrayed more instrumental detail and partly because it had greater spatiality, so that the castanets seemed more precisely defined in the soundstage. Although I’ve heard deeper bass, the V2 seemed to better the 450 in the bottom octaves, if only by a bit.
Finally, Lyn Stanley’s Potions [from the 50s] was too close to call; both units sounded very hi-res with instruments and voice. And oh, yeah, both Geek Outs swung!
The Geek Out 450 was an eye- and ear-opener, and the Geek Out V2 is even better. It offers a fully balanced circuit, which can matter if you have balanced headphones, and an improved 3D-printed case, whose much-improved ventilation for the circuit board results in cooler operation—and it looks incredibly spiffy. Spatial precision, harmonic completeness, and bass extension are improved over the already excellent Geek Out 450. Even if you have very expensive and capable headphones, the Geek Out V2 DAC/amplifier is worth a listen. In summary, I haven’t heard a miniature USB DAC/amplifier that sounds remotely as good as the Geek Out V2. I can hardly wait to hear some of LH Labs’ more advanced DACs.
SPECS & PRICING
Frequency response: 2Hz–55kHz (-0.1dB)
Maximum power output: 1000mW @ 16 ohms, 100mW @ 16 ohms (user switchable)
Maximum Output Voltage: 4.0V (high gain)
THD (THD+N): <0.01%
SNR: >105dB unweighted, >108DB A-weighted
Input: USB 2.0 (asynchronous)
Outputs: Dual 1/8″/3.5mm analog stereo (one single-ended TRS, one balanced TRS)
Output impedance: 0.47 ohms
PCM sample rates supported: 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz, 192kHz, 352.8kHz, 384kHz
DSD sample rates supported: 2.8224MHz, 3.072MHz, 5.6448MHz, 6.144MHz
Bit depth supported: 1-bit, 16-bit, 24-bit, 32-bit
Dimensions: 1.48″ x 0.51″ x 3.07″
Weight: 1.2 oz.
LH LABS CORP.
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Roseville, CA 95678