HeadAmp GS-X mini Review

HeadAmp has twenty years of experience crafting amps for everything from IEMs to electrostatic headphones. Conceived as a more compact version of their flagship solid state GS-X mk2, GS-X mini is designed to handle your complete collection of conventional dynamic and planar headphones. With a lower cost of entry, and a smaller footprint, can the GS-X mini still deliver big power?

Build and Design

There’s nothing particularly flashy or eye-catching about GS-X mini’s packaging or the unit itself, but the utmost care was clearly put into the design, build, and packaging. The box, emblazoned with the HeadAmp logo, contains just the amp itself and a power cable, all securely packed. The amp itself is a slim, but solidly built aluminum box with vents for heat management. It has a nice heft to it and feels very well built.

HeadAmp GS-X mini

For headphone outputs, you get 4-pin balanced XLR and 6.3mm for single-ended. On the back you also get XLR and RCA preamp outputs. GS-X mini being an amp, the input section is all analog with XLR and RCA for the inputs. The switching is all handled by a series of sturdy toggle switches on the front of the unit. You get power, High/Low Gain, Preamp mode, and RCA/XLR. High/Low gain, and RCA/XLR switching is pretty self-explanatory, and for Preamp mode, if it’s on, the rear outputs will be turned on and the headphone outputs disabled.

Sound and Performance

GS-X mini’s primary goal is to provide a clean, transparent, and loud output. To accomplish this, HeadAmp uses a fully discrete Class-A design to deliver impressive amounts of power to your headphones, with an accurate delivery and very low distortion. Obviously, “loud, clean, class-A” isn’t a fully unique idea, but it’s one that’s constantly being refined. And, of course, in the tuning there’s always a tightrope to walk between the too clinical/analytical sound and one that ends up being warm or losing detail. GS-X mini deftly walks this tightrope expertly, with a sound that values both accuracy and engagement.

HeadAmp GS-X mini

One of the key characteristics of GS-X is the incredibly low noise floor and pitch black background. The experience of listening to highly dynamic tracks which shift between near silence, soft vocals, and larger moments – like Kanye West’s “Ultralight Beam” – are greatly enhanced by GS-X mini’s ability to deliver such low noise. Any noise remains essentially imperceptible, even as the volume wheel goes up, and when the dynamics swell, they can provide an even bigger emotional contrast when the bottom is so low.

Along with the great dynamics and low noise, the range of useful output on the amp was also notable. The sound felt every bit as rich, layered, and dynamic in low gain at 10% volume in a more relaxed setting as it did cranked up to 50% on high gain (more than my ears could handle for very long with any headphones we had available.) You get the same top notch performance out of a more sensitive dynamic headphone like a Focal Utopia as you do with a hard to drive planar.

HeadAmp GS-X mini

The level of output power is, of course, the main event. GS-X mini can drive just about anything and drive it hard. With the ability to drive 6W into 25 ohm headphones or 4 watts into 50 ohms, you're going to have a hard time finding a headphone where GS-X mini can't deliver all the power it could ever ask for.

Comparison: Burson Soloist 3X Performance, SPL Phonitor SE

For comparison I brought in one of our best selling amps – and one widely regarded as a great performer for the money – the Burson Soloist 3X Performance. Along with that, the SPL Phonitor SE shares some design elements and has a similar ethos behind the design. For comparing the three, I used the RME ADI-2 DAC FS with the Audeze LCD-5, Audeze MM-500, and HIFIMAN HE1000v2 in single-ended.

In terms of the interface and design, the Burson stands out a bit with its OLED screen based configuration, with the Phonitor and GS-X mini having a simpler “knob and switches” design. Aspects of GS-X mini’s overall build and the feeling of the switches was a cut above, but I will say, the SPL guys really know how to make an incredible volume knob. Phonitor is the only one of the three to feature a crossfeed control as well, but it’s also lacking balanced inputs or outputs, so the comparisons here aren’t completely perfect.

To be totally fair, these are the sorts of amps, with the sort of sound, that compares sort of like Coke and Pepsi. If you have a soda with your cheeseburger once a week, you probably don’t care much, but to those with more refined tastes, there’s a clear difference. Likewise all three amps have a largely transparent, reference sound, but there’s actually a lot to compare and contrast for dedicated listeners.

HeadAmp GS-X mini

In the tuning, GS-X mini feels like the baseline between the two. Phonitor’s treble is pulled back the most of the three, with the Soloist having the most presence at the top with plenty of air to the sound. Phonitor and GS-X mini both have good weight in the midrange that lends a more holographic element to imaging, but GS-X mini’s stronger treble provides a greater sense of separation and definition of instruments. Soloist has the strongest definition, but doesn’t have the same weight in the mids.

In the bass, Soloist is fast and tight, but doesn’t hit with as much impact or slam as GS-X mini. Phonitor has a touch more emphasis down low, but feels a touch muddy by comparison to GS-X mini and Soloist. GS-X also provides more overall headroom, outpacing both units in volume without even going into high gain mode.

Overall, if GS-X mini is the baseline, Soloist is a little bright and Phonitor SE is a little warm – with all three still residing clearly in the neutral camp. While some of that might be down to preference (volume levels aside), where GS-X mini really takes the cake is the stereo image. The width and three dimensionality of the soundstage, and the weight and holographic sense to the image on the GS-X mini puts it a step above the competition.

Final Thoughts

While I have yet to hear the original GS-X, or its follow-up, the GS-X mk2, I find it hard to believe that with the level of power, performance, and overall quality, what I heard was at all “mini.” HeadAmp delivers top-notch hand-built quality, with an incredible – and big – sound, in the GS-X mini.