LHLabs Geek Out V2 Review and Measurements Going to keep things short as usual. I compared the Geek Out V2 with a combination of other gear which included the iFi Nano iDSD, the Schiit Modi 1, and the Magni 2. HD650s (coin modded and damping removed) were used, not an easy headphone to drive to its full potential, but I think a good test. I don't normally talk about stuff that can be found the specs or in the manuals, but there are couple things I felt should be mentioned. One of the things I did not like with the prior iteration of the Geek Out was that I had no idea if I was in FRM or TCM mode or what the buttons did. This time around, the user interface is much improved. The GOv2 has colored indicators for gain and filter settings. The bottom bottom selects the gain stages, the top button selects the filter. The bottom LED next to the "C" is blue for high gain and white for low gain. The top LED next to the "DM" is blue for TCM, green for FRM, and red for some filter that is supposed to be used with streaming services. As you can see in the picture, the V2 was used with the high gain and FRM filter. The red "streaming" filter sounded the worst; however I wasn't using any streaming sources. I played back only FLAC from JRiver. I know some people prefer TCM (minimum phase filter with no pre-ringing), but I've never liked this filter on any DAC that I've owned or evaluated that gave me this choice. So it's the linear phase filter for me, which would be the FRM "green" LED color. The subject of filters is entirely another topic and won't be covered here. I only want to add that the arguments (found in various marketing whitepapers) claiming reduced pre-ringing as being the most natural sounding are bullshit, at least in my opinion. I see it more as "different" than "musical natural". Finally, I wouldn't say that the FRM filter is better than TCM in every way, but rather that that FRM filter is a better match for what I like to hear. I'll let the rest of you guys open the door to this one with Q&A or perhaps chime in with your own experiences. So in a nutshell, I find the Geek Out V2 to be pretty darn good. This is something I wished I had on my trip to D.C. a few weeks ago. Let me summarize its strengths (taking into context its size and intended use): Resolving. Ambient decays, low level information, plankton are easily heard. Engaging. Comparatively excellent microdynamics. The prior GO tended to compress sounds, expanding loud and crushing softer sounds - a more exaggerated contrast. The V2 on the other hand does a very good job distinguishing between volumes and digging into the small swings. While not close to serious desktop DACs like Gungnir Multibit, I can easily say that the GO V2 is superior in this specific sonic attribute to all other portable DACs/amps that I've heard regardless of price. This includes the overpriced garbage from Chord (although the Hugo TT does some specific other things better). Those who know me understand this is my #1 consideration in evaluating gear. If I had to nickpick: Lack of power. Softness, and lack of ultimate macro-dynamic ability. The HD650s are notoriously difficult to drive well. They are super high impedance and love a ton of voltage swing. This puts something like the Geek Out V2, which is powered by the USB 5V power rails at a serious disadvantage. There is where balanced bridged circuits shine. Unfortunately I did not have any TRRS to XLR 4-pin adapters on hand. I suspect with the balanced outputs, the GOv2 might be brought to another level with the HD650. Lack of ultimate clarity, blackness, refinement and poise, probably related to #1. Now before people get worried, I need to put these criticisms in proper context, the iFi iDSD Nano was significantly worse in terms of softness and congestion. When the music got busy or loud, the iFi iDSD Nano (on a fully charged battery) sort of goes flub flub flub flub and gets confused and congested in the lower registers. In comparison, the Geek Out V2 does get softer on the impacts, but still maintains control and separation. For less stressful musical passages, the macro-dynamics on the Geek Out V2 were more impactful. For example, the crescendo on Neal Schon's guitar arpeggio leading up to the drum hits around the one minute mark of Don't Stop Believin' were much more believable on the Geek Out V2 than on the iFi. The Modi 1 / Magni 2 stack had equal macrodynamics and better clarity, blackness, and poise, but this comparison is rather unfair as the Magni 2 gets a huge AC 14V 1.4 amp power brick. I did find that the Geek Out V2 was superior in terms of resolution and engagement than this stack. The Modi 1 / Magni 2 was a tiny bit flatter and slightly less resolving than the Geek Out V2. Among the setups, the iFi was the flattest, most boring, and least controlled sounding, the Geek Out V2 was the most resolving and lively, and the Modi 1/2 was the most controlled and powerful. In terms of digititus and tonal balance, the Modi 1 is the most grainy and least warm. The Geek Out V2 (FRM) and iFi iDSD Nano are actually on par in terms of lack of digital nasties. Both exhibit a warm tonal balance. Both lack any significant digital sheen or glare, which is impressive for the Geek Out V2, being Sabre. While I've never thought highly of the iFi, I do have to acknowledge that one of its strengths is lack of digititus. In the end, don't expect R2R type sound though. Finally, I should mention that the Geek Out V2 in TCM mode is too digital sounding for me.