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Review: Aphex HeadPod 4 Four-Channel Headphone Amplifier

For several years now, I’ve relied on the first-generation Aphex HeadPod — marketed as the HeadPod 454 — headphone and IEM amp. My colleague, Charlotte NC studio owner Rob Tavaglione, originally reviewed the Aphex HeadPod 454 for PAR upon its initial release, and Daniel Kumin bench tested the same unit. To summarize, the 454 was “loud and clear” as well as “rugged, attractive and built to last.” 

The same goes for Version 2 — a.k.a. HeadPod 4 — as spearheaded by relatively new Aphex owner David Wiener (, a successful design-based entrepreneur with a broad resume of engineering, art and aerodynamics projects. Wisely, his redesign changed only a few of HeadPod 454’s solid specifications, thus Rob and Daniel’s performance findings remain accurate for the HeadPod 4. But what could be dismissed as predominantly cosmetic updates are more than that; after all, it’s often small refinements that make good products great. Wiener clearly understands that, when inspired, style- and shape-based refinements can truly improve something as humble and straightforward as a desktop four-channel headphone amp. 

And yes, this v2.0 now provides digital input (via S/PDIF), too. 


Aside from the new digital source input, HeadPod 4 is a “like father, like son” story; it too is self-explanatory in use and feeds your headphone or IEM of choice — or, top four of choice — as much clean, uncolored gain as an engineer, producer, musician or casual listener would need — except for those that have (or want) significant hearing damage. Thus, even the 454’s clunky “Turn Down Volume Before Plugging In” warning on its faceplate was refined (“Caution: Check Volume Before Use”), while maintaining the sentiment, on the HeadPod 4.

The HeadPod 4 features four individual stereo power amps, each with a quarter-inch TRS output; two balanced quarter-inch TRS analog inputs, left and right channels (Analog 1 via HeadPod 4‘s three-position Input Select); an unbalanced quarter-inch TRS stereo analog input (Analog 2); Coaxial (RCA) S/PDIF (IEC 60958) digital input, accepting 16- and 24-bit resolution, 44.1 kHz, 48 kHz, 88.2 kHz and 96 kHz sample rates (Digital). All inputs, plus DC power supply input and a new power on/off switch (significantly absent from the first HeadPod) are on the rear panel; all outputs are on the front panel. 

Gone is HeadPod 454’s glaringly-bright blue-white “On” LED (which, in a dark studio, could justifiably be called “blinding”). Now, HeadPod 4 has a subtle green backlit “Aphex” logo to show its On status, plus a smaller, plenty-bright small green LED to show present digital signal input. 

Other specifications include a maximum gain level of 35dB, maximum input level of +24dBu (balanced and unbalanced), weight of 16 oz., and dimensions of 5.5” x 1.9” x 4.5” (width x height x depth). Aphex offers a limited one-year warranty covering all defects in materials and workmanship. 

With a design that remains Apple-influenced, HeadPod 4‘s user interface — no longer characterized by a rounded top panel in “iMac white” with smooth silver knobs — is what I’ll call “masculine Mac,” comparatively angular and chiseled, featuring a MacBook-complimentary metal silver chassis, knurled black knobs and beveled edges all around. On that note, it seems the entire Aphex line has been redesigned/repackaged with this same aesthetic. 

In Use

During the evaluation period, I simply swapped out my HeadPod 454 for the HeadPod 4 and continued with my normal work; this ranged anywhere between basic track cutting with multiple listeners, mixing ITB with multiple headphone and IEM references, and critical listening via each input source — balanced and unbalanced analog as well as 16- and 24-bit resolution, 44.1kHz or 88.2kHz sample rates.

The new digital input was especially nice when listening back to original stereo masters from an Alesis Masterlink at 24-bit/88.2kHz via S/PDIF. The HeadPod 4’s manual touts its “much higher quality” DAC compared to “those found in audio interfaces and digital mixers.” From what I heard, I would vouch that the combination of the HeadPod 4’s DAC and headphone amplifier stage yielded no compromise conversion, amplification and fidelity. My headphones and IEMs all sounded at their best. Aphex’s claim of superiority to the built-in converter and amps in interfaces and mixers rings true, particularly considering the performance of the headphone circuits in the lower price-point interfaces and mixers in our marketplace (and it for sure was true when I compared the HeadPod 4 to the headphone output of the Masterlink). 

In application, I never had a need for more gain, whether critically listening via premium headphones or as a performer, interchangeably wearing premium custom-fit IEMs and lower-cost headphones while cutting live acoustic drum tracks at full volume. Again, the phrase “loud and clear” comes to mind — and, for a simple four-channel headphone amp, what else do you really need? 


The HeadPod 4 is a perfect little desktop (or studio floor) monitoring tool: compact, great-sounding and, yes, visually striking. It would be my first recommendation to anyone in need of a solid and simple four-channel headphone amp. 

Strother Bullins is a musician, self-recordist and the Editor of Pro Audio Review

Price: $249 list 

Contact: Aphex