Innuos PhoenixUSB USB Reclocker

The PhoenixUSB started as a specific internal problem. Innuos was building the Statement — their flagship server — and the USB output stage demanded a level of clocking precision and power supply isolation that didn't exist in any off-the-shelf solution. So they engineered it themselves. The Statement's USB circuitry became one of the most discussed aspects of the product. Dealers and reviewers noticed. Then someone at Innuos made the obvious move: put that USB stage in its own box, make it work with any source, and sell it separately. That's the PhoenixUSB. Five-plus years into its existence, with awards from nearly every major English and European publication that reviewed it, it remains the benchmark by which USB reclockers are measured.

What It Actually Does

A clarification worth making upfront: the PhoenixUSB doesn't reclock the audio signal. It reclocks the USB communication itself. USB operates at 24MHz — that's the clock frequency that governs the protocol layer, independent of whatever audio sample rate you're transmitting. Noise on that communication layer contaminates the signal the DAC receives, even if the DAC has its own internal clocking. The PhoenixUSB takes the incoming USB signal, completely regenerates it against its own precision clock reference, and outputs a dramatically cleaner signal to the DAC.

This distinction matters because it means the PhoenixUSB works with any DAC that accepts USB input and any USB source — Innuos or otherwise. It's not an Innuos-only accessory. Drop it between a laptop and a DAC, between a Roon Nucleus and a DAC, between any streaming device and its USB DAC. If the connection is USB and the DAC is capable, the PhoenixUSB will improve it.

The Engineering

Three design decisions define the PhoenixUSB, drawn directly from the Statement's internal architecture.

First: no switching regulators anywhere near the USB chip. The USB chip requires three independent voltage supplies. In virtually every other device — computers, streamers, even expensive dedicated servers — at least some of those voltages come from switching regulators, which generate noise by design. The PhoenixUSB supplies all three from an independent linear power supply, with each voltage rail further regulated by a dedicated set of LT3045 regulators. LT3045 is a precision low-dropout linear regulator with ultralow noise characteristics — essentially a reference-grade device that audiophile power supply designers use when they need the cleanest possible rail. Three sets means each voltage is treated as its own isolated supply.

Second: a 3ppb OCXO clock at 24MHz, mounted directly on the board a couple of inches from the USB chip. An oven-controlled crystal oscillator (OCXO) maintains its frequency with exceptional precision by keeping the crystal at a constant temperature regardless of ambient conditions. The 3ppb (parts per billion) accuracy specification puts this in the same category as clocks used in broadcast and test equipment. Crucially, it connects to the USB chip via a short board trace rather than a cable. Every connector and cable in the signal path introduces potential degradation — mounting the clock this close eliminates that entirely.

Third: two completely independent Statement-level linear power supplies. One dedicated to the OCXO clock. One dedicated to the USB chip and the 5V USB power line delivered to the connected DAC. Keeping these supplies separate means the current draw variations of the USB chip don't contaminate the clock's supply, and vice versa. This is the same isolation philosophy Innuos applies in the Statement's internal design — separate supply rails for every critical function.

Our Experience

We've run the PhoenixUSB in-house across multiple systems. The consistency of the improvement is what stands out. Systems where we expected marginal gains — sources that were already well-engineered, DACs with their own sophisticated internal clocking — still showed meaningful changes: tighter bass, better defined leading edges, an ease in the upper midrange and treble that's hard to describe until you hear its absence. Jay Luong at Audio Bacon called it a necessity rather than an accessory. That's about right. Once you've heard a USB connection through the PhoenixUSB, going back is difficult.

One pairing worth singling out: the PhoenixUSB with an Innuos ZENith Mk3 was frequently cited in reviews as pushing that server toward Statement performance levels. The same principle applies to the current STREAM1, STREAM3, ZEN Next-Gen, and ZENith Next-Gen — the PhoenixUSB as an outboard unit extracts more from any of them, even when those servers already have the PhoenixUSB Board fitted internally. The outboard unit uses a larger chassis and more substantial power supplies than the internal board can accommodate.

Where It Fits

The PhoenixUSB belongs in any system where a USB DAC is the endpoint and the digital source matters. That's most serious systems. The remaining question is whether your DAC is resolving enough to reveal what the PhoenixUSB does — and in our experience, if your DAC costs more than a few thousand dollars, the answer is almost certainly yes. Below that threshold the improvement is still real, but the value proposition becomes a question of priorities.

Innuos offers 20% off the PhoenixUSB when purchased alongside any Innuos server or streamer. Worth taking if you're already configuring a system — the discount is meaningful at this price.

Press Recognition

The PhoenixUSB has accumulated more independent press recognition than almost any other product in the Innuos range. A representative selection:

Hi-Fi+, Alan Sircom — two separate reviews, including a combined piece in Issue 244 with the PhoenixNET. Sircom's verdict: the PhoenixUSB raises digital audio out of the ashes of noise. Earlier in a standalone review he described its 10-second audibility test as conclusive evidence that it's the real deal. Read the combined review.

Hi-Fi Pig, Alan McIntosh — Five Hearts Award. McIntosh found the sonic contrasts from adding the PhoenixUSB more apparent and substantial than many DAC-to-DAC comparisons — improved bass density, wider imaging, sharper focus, heightened top-end energy. Concluded it a must-have, and noted its standalone nature means it survives future DAC or source changes. Read the review.

Fairaudio, Fritz Schwertfeger — Fairaudio's Favorite Award 2021. After weeks of listening Schwertfeger concluded the PhoenixUSB was converting digital sound into what he described as analog naturalness: less stress, more confidence, finer resolution of musical lines. Read the review (German).

The Ear, Jason Kennedy — Editor's Choice and Best of 2020. Kennedy found the PhoenixUSB delivered the best sound he'd heard from a USB connection, with significant gains in timing and definition that made instruments more solid and coherent and deepened the soundstage. Read the review.

Darko Audio, John Darko: Darko described the PhoenixUSB as advancing digital front-end performance closer to where listeners want it to be, and called it a straightforward endorsement. Read the review.

Audio Bacon, Jay Luong — Finest Cuts Award. Luong's assessment: this component is more of a necessity than an accessory, even for casual listening. The result is sound you could feel. Read the review.

Hi-Fi Knights, Dawid Grzyb — Victor Award. Grzyb placed the PhoenixUSB as the best USB device he'd heard, calling it audio therapy for well-sorted systems, and found no other USB solution as capable. Read the review.

Audiophile Style, Austin Pop: Found the PhoenixUSB allowed ZENith SE owners to approach Statement sound quality while preserving their investment — and found it outperformed his existing multi-component USB optimization chain. Read the review.

Hi-Fi IFAs, Falk Visarius — Checkpoints Hammer Award. Visarius found the PhoenixUSB improved every sonic aspect: more authentic reproduction, easier retrieval of fine detail, better bass contour, more relaxed overall presentation. Read the review (German).

Additional recognition: HiFi Einsnull award; Hi-Fi Pig Pick of the Year 2023.

Specifications

• Function: USB signal regenerator and reclocker
• Clock: 3ppb OCXO at 24MHz, board-mounted adjacent to USB chip
• USB Chip Power: Three independent voltage rails, each regulated by dedicated LT3045 linear regulators — no switching regulators on any voltage
• Power Supplies: Two independent Statement-level linear power supplies — one dedicated to OCXO clock, one dedicated to USB chip and 5V USB output line
• Connectivity: 1 x USB input (Type B), 1 x USB output (Type A)
• Compatibility: Any USB Audio Class 2 DAC; any USB source (Innuos or third-party)
• Mains: 115V / 230V AC (switchable); two internal linear power supplies
• Power Consumption: 3W idle, 7.5W peak
• Dimensions: 215 x 342 x 87mm (W x D x H)
• Weight: 5 kg
• Includes: PhoenixUSB reclocker, mains cable, USB cable, getting started guide
• Country of Origin: Portugal

If you want to hear what the PhoenixUSB does in the context of your specific source and DAC before committing, reach out. We're happy to talk through whether it makes sense for your chain — and if the bundle discount applies to your situation, we'll make sure you get it.