Phonitor 3 DAC headphone amp & monitor controller
A couple of years ago, I moved my studio, SoundShop370, from Manhattan to South Nashville. Since then, I’ve been refining my setup, making sure every piece of gear I use is intentional, functional, high-quality, and built for long-term reliability. Headphones have always played a role in my workflow, but over time they’ve become more critical – not just for tracking but also for mixing and referencing. However, if you’ve ever attempted to mix on headphones, you know the challenge: The stereo image feels exaggerated, spatial cues are different than with loudspeakers, and balancing the low end can be a guessing game.
I’ve used SPL gear in the past, and they’ve always had a reputation for pristine audio quality and solid, excellent build quality. But the Phonitor series is something different: It’s a dedicated solution to a problem that’s become increasingly relevant in modern studios. With more people mixing on headphones than ever before, the need for an accurate, speaker-like headphone experience has never been greater. That’s exactly what the Phonitor 3 aims to solve. Right out of the box, the Phonitor 3 feels like a serious piece of equipment. The black-painted, all-metal chassis is rock solid, and every control has a satisfying, tactile feel. SPL doesn’t cut corners on build quality, and this unit makes that abundantly clear.
On the connectivity front, the Phonitor 3 is more than just a headphone amp – it’s also a full-fledged monitor controller and DAC. There are two stereo pairs of balanced analog XLR stereo inputs and a single stereo pair of XLR outputs for connecting to monitors. Switching between sources is effortless, thanks to the six-position rotary switch on the front panel. The large Volume control is an ultra-smooth, machined aluminum knob that feels as premium as they come. However, the star of the show is the headphone amplifier. SPL designed it with ±60 Volt rails, providing an absurd amount of headroom, low noise, and ultra-low distortion. It can drive everything from high impedance studio headphones to lower-powered consumer models without breaking a sweat. The output impedance is practically nonexistent, ensuring your headphones perform consistently without coloration.
What really sets the Phonitor 3 apart is its Matrix. If you’ve ever struggled with translating your headphone mixes to speakers, this feature is designed to address that. There are three key controls in the Matrix. Crossfeed blends a small amount of the left channel signal into the right ear and vice versa, mimicking how sound naturally interacts with both ears in a loudspeaker setup. It also applies filtering to maintain a balanced frequency response. This feature is crucial in preventing the "inside your head" feeling I often get when mixing on headphones, helping create a more immersive and natural stereo image. The Angle control simulates the time delay between loudspeakers and your ears, emulating different stereo placements. Adjusting this control helps replicate the effect of listening to speakers from different angles, offering more depth and space to your mix. It positions the soundstage more naturally, especially for those used to working on loudspeakers and wanting that translated headphone experience. The Center control allows for monitoring the level of center-panned elements, which is helpful as a mixing tool to prevent them from feeling overly pronounced in the middle – a common issue when mixing on headphones. This adjustment ensures your mix translates better and feels more in line with a natural listening experience, especially when it comes to panned vocals or bass. At first, these Phonitor Matrix controls might seem subtle, but the more I used them the more I realized their impact on my work. Instead of feeling like the mix was trapped inside my head, the soundstage opened up and felt more natural – closer to what I experience on loudspeakers. Once I got used to it, switching back to a regular headphone signal felt wrong.
At its core, the Phonitor 3 is an outstanding headphone amp. No matter what headphones I used, whether it was my AKG K812s or Audio-Technica ATH-M50x [Tape Op #113], the detail, clarity, and depth were exceptional. The transient response was fast, the low end was tight and controlled, and stereo imaging was sharp. The sound was not just "clean," it was effortlessly clean, making it easy to hear and address issues in a mix – and that’s what really makes the Phonitor 3 special. It’s not simply about enabling headphones to sound their best, it’s about making them trustworthy as a mixing tool.
The SPL Phonitor 3 isn’t a budget buy, and it’s not trying to be. This is a tool for professionals who need absolute precision in their monitoring, whether on speakers or headphones. While the Phonitor Matrix won’t completely replace a fine pair of monitors in a well-treated room, it gets incredibly close, and in some cases, such as with late-night mixing, it’s an absolute lifesaver.
For those who rely heavily on headphones in their workflow, the Phonitor 3 is one of the most useful and sonically-transparent monitoring tools you can add to your setup. Its build is robust, it sounds phenomenal, and it does exactly what it claims to do. In today’s world, where headphone mixing is more common than ever, that’s no small thing. ($1899 MAP; spl.audio) -Tony Vincent
