Monday 24 August 2015

LH Labs Geek Out V2 USB headphone amp/DAC

LH Labs Geek Out V2

Many people think that the first big audio crowd-funding success story was Neil Young’s PONO launch, but that’s not the case. LH Labs Geek Out USB DAC brought in $303,000 and its Geek Pulse and Geek Wave brought in respectively an unprecedented $2.9million and $1.665million in their respective Kickstarter campaigns. Since then LH Labs has rolled out numerous Geek Out products for both portable and home use. Their latest product, the $299 Geek Out V2, was the company’s first pre-order campaign on Indiegogo, with $345,000 in advance orders. As opposed to crowd-funding, pre-order campaigns allow faster delivery times, at least in theory. Let’s look at LH’s Geek Out V2 to see if this new DAC delivers the same level of performance as previous award-winning Geek Out components.


Packaging for the Geek Out V2 is simple – the cellophane-wrapped outer sleeve box holds a piece of felt-covered foam with a cutout where you’ll find the V2 along with a 9cm by 15cm triple-fold owner’s manual. No additional cables, connectors, or carrying case are included, but the optional LightSpeed Extender USB cables are avaialble.

The Geek Out V2 is 78mm long, 37.5mm wide and 13mm thick, or approximately the same size as a Zippo lighter. Its case is made of 3D-printed high-temperature resin that features a curvy graphic and a lot of open space for air circulation. Ventilation slots for heat dissipation populate almost the entire backside of the V2. The V2’s top has a standard USB 2.0 connector while the bottom has single-ended and balanced mini-plug output connectors. One side of the V2 has two buttons. The top button switches between two gain settings (100 and 1000mW) while the bottom switches between three user-selectable digital modes. These three modes are Time Coherence mode which uses a minimum phase filter to remove pre-ringing from the signal; Frequency Response mode which uses a slow roll-off digital filter; and Stable Streaming mode which is optimized for streaming sources. Power for the Geek Out V2 comes from your computer as the V2 itself has no batteries or internal power source. If you plan to use the V2 attached to a USB dock, make sure it is a powered one.

The Geek Out V2 supports all PCM formats up to 384/32 and DSD up to 128x. It has both balanced and single-ended outputs and the digital circuitry is based around the ESS SABRE9018AQM DAC chip. The analogue section of the V2 utilizes a pure class-A design, which like all Class-A designs, generates substantial amounts of heat. The board-mounted heat sinks and extensive ventilation on the V2’s chassis were created to help alleviate any heat build-up problems.

Setting up the V2 is simple. For a Mac OS, you merely have to plug it in and the Mac will recognise it immediately. The next step is selecting the V2 as your audio output via Apple’s Midi Control Panel and you are all ready to play music. With Windows PC you will need to download a driver from LH Labs’ website, install it, and then select the Geek Out V2 as your audio device.

Upon setup the first thing a user will want to know is, “How do I adjust the volume?” The Geek Out V2 has no volume control knobs or switches besides the two-position overall gain control. On a Mac you can use the master volume slider or the volume sliders in your playback application to adjust the volume. And although you adjust the volume via digital controls, the volume is not attenuated by your computer. The Geek Out itself has a 64-step lossless volume control so even at the lowest output levels no data is lost.

During the review period I used a wide range of file types and resolutions from 320 MP3 and FLAC streaming to my own 192/24 and DSD 128x live concert recordings. Not once did the Geek Out V2 balk or play any of the files at the wrong speed (don’t laugh; I’ve used several DACs recently that occasionally play PCM and DSD files at the wrong speed, though switching to another track and then going back to the desired track usually solved the problem).

In the early days of the current headphone revolution it was a status symbol to own a pair of headphones that were difficult to drive because then you could complain about all the headphone amplifiers, especially portable headphone amplifiers, that could not drive your “cans” to what you considered adequate volume levels. This ‘power imperative’ encouraged portable DAC/headphone amplifiers to increase their new introductions’ power capabilities. The Geek Out V2 is far more powerful than any first or even second-generation portable DAC/headphone amplifier I’ve seen. But headphone manufacturers, even those responsible for some very hard to drive headphones, have now begun to produce far more efficient headphones, so prospective buyers of headphones and amplifiers need to look carefully at both their headphone’s power requirements and their DAC/AMP’s power capabilities to put together a system that is optimally matched. Given the Geek Out V2’s 1000 mW power capability, obviously it was designed to handle high-impedance, low-efficiency headphones.

If you are the proud owner of a pair of high-efficiency in-ear monitors, such as the Westone ES5 or JH Audio Roxanne, using them with the Geek Out V2 could present some problems depending on your playback software. ROON was the best interface with the Geek Out since it has a 0 to 100 calibrated master volume control. With both the Westone and the JH Audio custom-fit in-ear monitors my volume settings were down at the low end of the scale between 8 and 17 with the Geek Out in low-output mode. The iTunes volume slider was only 1/3 of the way up at maximum volume levels. The good news is that unlike many high-gain headphone amps I’ve heard, the Geek Out V2 does not generate additional hum or hiss even with ultra-sensitive earphones. So while the Geek Out V2 wasn’t designed principally for high-sensitivity earphones, it does work better in this application than many amps designed to handle primarily difficult loads.

The least efficient headphones I had on hand are a pair of beyer-dynamic DT990 600 ohm version. In the high gain mode at maximum volumes I was running at 27 out of 100 in Roon while in iTunes the slider was never more than ¼ of the way up. Although I don’t own any difficult-to-drive or especially ‘power hungry’ headphones, given the additional gain and power capabilities of the V2, I can’t imagine how anyone will find a pair of headphones that can’t be powered to well above what we humans refer to as ‘loud’ when attached to the V2.

If you are looking for a closed-ear budget-friendly pair of headphones to mate with the Geek Out V2 I heartily recommend the new AKG K-553 closed-ear headphones sold through Massdrop ($120US). They fold flat so you can pack them easily and they are efficient enough that you could use them with your smartphone if need be. But if you want to hear the K-553 headphones full capabilities tether them to the V2. When connected to the V2 the K-553’s bass had substantial drive and impact. Low bass definition rivalled some far more expensive headphones.

The most synergistic headphones with the Geek Out V2 were the Audeze LCD-2 and HiFiMan HE-560. Coupled to the V2 both of these headphones produced a well-defined and specific image that was full of musical information. Bass with both headphones was well controlled with excellent low frequency extension. Treble was airy and smooth with no signs of any harmonic discontinuities or aberrant frequency response. The only negatives with both these headphones is the connection to the V2 – once you add an adapter to get from 1/4 inch headphone to mini-stereo, you end up with a 4” long column of metal coming off the back of the V2 that weighs more than the V2 itself.

While I understand why LH Labs chose to use the kind of USB connection they did, I still dislike it for several reasons. The principle reason is that it can put the Geek into awkward and possibly perilous playback positions. If I insert the V2 into one of the USB connections on the back of my MacPro titanium trashcan desktop, the V2 ends up hanging in space, just waiting for something or someone to knock into it or pull it out. And if you attach the kind of heavy headphone cable that often accompanies an audiophile headphone to the V2, the additional weight can pull the USB connection right out of the MacPro.

Hooked up directly to a MacPro portable’s USB slots the V2 ends up with its primary heat vents pointing downwards with virtually no airspace below. That makes for a hot-running unit. The obvious solution is to put some kind of USB extension cable between the Geek Out V2 and your USB outputs. Ideally, LH should have included a USB extension cable with the Geek Out V2, just as they did with the original Geek Out. If you buy a Geek Out V2 you simply must get a USB extension cable for it.

The LH Labs Geek Out V2 is an ultrapowerful portable DAC/headphone amplifier that was designed to handle the most challenging and difficult to drive headphones. If you have headphones that don’t require a lot of power, the V2’s most outstanding attribute could very well be underutilized. But if you need the power, the Geek Out V2 can deliver the goods in a clever, compact, and highly portable package. Highly recommended, even if you aren’t a fan of Kickstarter campaigns!

LH Labs Geek Out V2 USB


TECHNICAL SPECIFICATIONS

Type: USB DAC and headphone amp
Frequency Response: 2Hz-55kHz (–0.1dB)
Max Power Output: User switchable 1,000mW @ 16Ω, 100mW € 16Ω
Max. Output Voltage: 4.0Vrms (high gain setting)
THD+N: < 0.01%
S/N: >105dB unweighted, >108dB A-weighted
Input: USB 2.0 (asynchronous)
Outputs: Dual 3.5mm analogue stereo (one TRRS balanced, one single-ended)
Output impedance: 0.47Ω
Sample rates supported: 44.1kHz-384kHz (PCM), 2.8224MHz-6.144MHz (DSD)
Bit rates supported: 1bit-32bit
Dimensions (W×H×D): 37.5 × 13 × 78mm
Weight: 34g
Price: $299 (+shipping)

Manufactured by: LH Labs
URL: www.lhlabs.com
URL: https://www.indiegogo.com/projects/geek-out-v2-the-world-smost-powerful-compact-amp#/story