Audio T Verdict
The Innuos PhoenixUSB is a specialist digital upgrade for systems in which a music server, streamer or computer sends audio to a separate DAC through USB.
It sits between the USB source and DAC, receives the incoming USB data and retransmits it using a high-precision internal clock. At the same time, it provides a clean 5V USB supply from its own linear power-supply circuitry.
The PhoenixUSB effectively combines three components within one enclosure: a USB regenerator, a dedicated linear power supply and an external master clock with its own independent linear supply.
At the centre of the design is a 3-parts-per-billion oven-controlled crystal oscillator operating directly at 24MHz. It is positioned close to the USB regeneration chip rather than feeding the circuit through an external clock cable and another conversion stage.
The USB chip uses no switching regulators. Its three independent voltage rails originate from a linear power supply and receive further regulation from three sets of ultra-low-noise LT3045 regulators.
A second independent linear supply is dedicated to the OCXO clock, separating its power requirements from those of the USB regeneration circuitry and 5V USB line.
The PhoenixUSB does not decode music, store files, provide streaming services or convert digital audio into an analogue signal. It preserves the original USB connection between the source and DAC while improving the electrical and timing environment in which that connection operates.
Its effectiveness will depend on the quality of the source, DAC, USB interfaces and wider system. In a modest setup, the available budget may produce a greater improvement when spent on the DAC, amplifier or loudspeakers. In a well-developed digital system, however, the PhoenixUSB can provide a valuable upgrade without replacing the existing streamer or converter.
The standalone PhoenixUSB has now ceased production, although Innuos continues to provide technical support. Remaining, clearance or ex-demonstration stock should therefore be checked individually for finish, condition, warranty and availability.
Innuos PhoenixUSB USB Reclocker
The Innuos PhoenixUSB is a standalone USB regeneration and reclocking component designed for use between a compatible digital audio source and USB DAC.
It receives USB data through its input, regenerates the USB connection using its internal high-precision clock and outputs the signal to the connected DAC through a clean USB interface.
The design is based on technology developed for Innuos’s former flagship STATEMENT music server and brings the principal USB regeneration, clocking and linear-power-supply functions into a separate component.
Discontinued Product
Innuos has officially ceased production of the standalone PhoenixUSB.
The manufacturer states that discontinued products remain supported by its technical service, but new availability, finishes and replacement stock may be limited.
- Check current Audio T stock before ordering
- Remaining units may be clearance or ex-demonstration
- Confirm whether the selected unit is Black or Silver
- Confirm the warranty applying to the individual unit
- Inspect the supplied mains and USB cables
- Discuss current Innuos reclocking alternatives where appropriate
What Does a USB Reclocker Do?
A USB audio connection carries data, timing and electrical power between a source and DAC.
The source may contain switching power supplies, processors, storage devices and other circuitry that contribute electrical noise to the USB connection.
The timing and electrical quality of the USB interface can also vary between computers, music servers and streamers.
The PhoenixUSB operates as a USB hub device. It receives the USB packets from the source and resends them through a newly generated USB connection using its own high-precision clock and low-noise power supply.
The DAC remains responsible for decoding the audio format and converting the digital signal into analogue sound.
Three Components Within One Enclosure
Innuos describes the PhoenixUSB as providing the equivalent of three separate digital-audio components:
- A USB signal regenerator
- A dedicated linear power supply for the USB circuitry and 5V line
- A high-precision external master clock with its own linear power supply
Combining these functions allows the clock, USB controller and power supplies to be connected over short internal board tracks rather than several external cables.
Complete USB Signal Regeneration
The PhoenixUSB does not simply filter the incoming 5V line or place a passive component around the existing USB signal.
It receives the incoming USB packets and establishes a new outgoing USB connection to the DAC.
This allows the outgoing interface to operate from the PhoenixUSB’s own clock and power-supply architecture rather than relying entirely on the electrical environment of the original source.
3ppb Oven-Controlled Crystal Oscillator
The master clock is a 3-parts-per-billion oven-controlled crystal oscillator.
An OCXO maintains the crystal within a controlled thermal environment, reducing the frequency variation that can occur as operating temperature changes.
The 3ppb specification describes the oscillator’s stated frequency accuracy rather than an audio sampling rate or digital-file resolution.
Direct 24MHz Clocking
The OCXO runs directly at the 24MHz frequency required by the USB regeneration circuit.
Innuos positions the clock only a short board-track distance from the USB chip.
This avoids using a separate external 10MHz reference-clock connection followed by another internal clock generator to create the USB operating frequency.
Short Internal Clock Path
Clock signals can be affected by the additional connections, cables and conversion stages placed between the oscillator and the circuit being controlled.
The PhoenixUSB’s internal arrangement keeps the oscillator close to the USB chip and uses a direct printed-circuit-board connection.
The approach is intended to reduce unnecessary losses and interference within the clock path.
No Switching Regulators on the USB Chip
The USB regeneration chip contains no switching voltage regulators.
Instead, its three required voltage rails originate from a dedicated internal linear power supply.
This avoids placing high-frequency switching regulation immediately beside the sensitive USB and clock circuitry.
Three Sets of LT3045 Regulators
Each of the USB chip’s three voltage supplies receives additional regulation from ultra-low-noise LT3045 regulator circuitry.
Separate regulation helps prevent the changing power requirements of one section from influencing the other voltage rails unnecessarily.
The complete arrangement is intended to provide a lower-noise operating environment for the USB controller.
Twin Independent Linear Power Supplies
The PhoenixUSB contains two independent Statement-derived linear power supplies.
One supply is dedicated to the OCXO master clock.
The second supplies the USB regeneration circuitry and clean 5V USB line.
Separating the clock and USB circuitry reduces the likelihood of their changing current demands interacting through one shared regulator.
Clean 5V USB Supply
The outgoing USB connection includes a 5V line derived from the PhoenixUSB’s internal linear power supply.
Some DACs require this line to initialise their USB interface even when their principal audio circuitry has its own mains supply.
Other compact DACs may draw more of their operating power directly from USB.
The PhoenixUSB supplies a clean 5V connection rather than passing the original source’s USB power line straight through to the DAC.
Do Not Use a Power-Blocking USB Cable Without Checking
Some specialist USB cables disconnect the 5V conductor.
A DAC may fail to appear or initialise if its USB interface requires the 5V line. Confirm the DAC and cable requirements before using a power-blocking design.
Transparent USB Hub Operation
The PhoenixUSB behaves as a USB hub between the host source and connected DAC.
The source remains responsible for identifying the DAC and selecting the appropriate audio driver or output mode.
The DAC remains responsible for declaring which sample rates, bit depths and audio formats it supports.
The PhoenixUSB does not convert one digital format into another or impose an independent playback application.
No Published Format Conversion Limit
Innuos does not publish a separate PCM or DSD conversion limit for the standalone PhoenixUSB because it operates as a USB regenerator rather than a digital audio decoder.
Practical playback capability depends principally on:
- The source and playback software
- The connected DAC’s USB interface
- The DAC’s supported PCM and DSD formats
- The computer driver where one is required
- The USB cables
- The wider operating system and playback configuration
USB Input from the Source
The rear USB input connects to the USB host output of a compatible music server, streamer or computer.
The PhoenixUSB quick-start arrangement uses a conventional USB connection from the source’s Type-A host output to the PhoenixUSB Type-B input.
A source fitted only with USB-C may require a suitable data-capable USB-C cable or adaptor.
USB Output to the DAC
The regenerated USB output is provided through a Type-A host connection.
This normally connects to the USB Type-B audio input on the DAC using a USB A-to-B cable.
A suitable USB cable is supplied with the PhoenixUSB, although the complete installation requires a cable on both sides of the reclocker.
Two USB Cables Are Required
One cable connects the source to the PhoenixUSB input.
A second cable connects the PhoenixUSB output to the DAC.
The cable previously used directly between the source and DAC can normally be reused on one side of the PhoenixUSB, subject to its connector types and condition.
Compatible Source Components
The source must operate as a USB host and be capable of sending audio to an external USB DAC.
Possible sources include:
- Innuos music servers and streamers
- Third-party music servers
- Network streamers with USB audio output
- Windows computers
- Apple Mac computers
- Linux-based audio servers
- Selected compact streaming transports
A USB connection intended only for storage, charging, backup or service may not operate as an audio host output.
Compatible DACs
The DAC requires a compatible USB audio input and must work correctly with the source before the PhoenixUSB is added.
Many current DACs use USB Audio Class 2, allowing high-resolution PCM and DSD playback from a suitable server or computer.
Windows DACs may require the manufacturer’s driver, while Mac and Linux systems often use class-compliant operation.
Test the Direct Connection First
Connect the source directly to the DAC and confirm that music plays correctly before adding the PhoenixUSB.
This establishes that the source, DAC, driver, playback settings and USB cable are functioning normally.
USB Audio Class 2 DACs
The PhoenixUSB is particularly relevant to systems using a USB Audio Class 2 DAC.
This standard supports higher PCM sampling rates and broader format compatibility than the older USB Audio Class 1 specification.
The exact maximum resolution is determined by the source, driver and DAC rather than by a format menu within the PhoenixUSB.
Not Limited to Innuos Sources
The standalone PhoenixUSB is not restricted to an Innuos server.
Innuos describes it as receiving the USB signal from any suitable source and its support information explains that the device operates as a general USB hub.
Compatibility should still be checked where a source uses an unusual USB implementation or proprietary output mode.
No Software or App Is Required
The PhoenixUSB has no control application, network interface or user configuration menu.
There is no separate Innuos Sense setup for the reclocker itself.
The source should continue to display and control the connected DAC in the same way as it does during a direct USB connection.
No Front Power Button
The PhoenixUSB does not have a front-panel power button or operating light.
Power is controlled using the mains switch on the rear panel.
The clean front panel is therefore free from an illuminated status display that could introduce additional electrical activity.
Power-On Sequence
Before making connections, switch off the source, DAC and PhoenixUSB.
Connect the source to the USB input and the DAC to the regenerated USB output.
Connect the mains cable and switch on the PhoenixUSB at the rear.
Then power the source and DAC according to their normal operating instructions and select the DAC as the playback output.
Power-Off Procedure
Stop music playback before switching off the digital components.
Reduce the amplifier volume or mute the system to prevent unwanted noises reaching the loudspeakers.
Use the rear mains switch when the PhoenixUSB must be powered down or disconnected.
What the PhoenixUSB Does Not Do
The PhoenixUSB is not a complete digital source or converter.
- It does not store music
- It does not rip CDs
- It does not connect to streaming services
- It does not run the Innuos Sense app
- It does not contain a DAC
- It does not provide analogue audio outputs
- It does not provide optical, coaxial or AES outputs
- It does not control playback volume
- It does not operate as a network switch
- It does not replace the source or DAC
Not a Digital-to-Analogue Converter
The PhoenixUSB does not convert digital music into an analogue signal for an amplifier.
A separate DAC or a digital amplifier with a compatible USB audio input remains essential.
The DAC’s analogue outputs then connect to the amplifier or active loudspeakers.
Not a Network Streamer
The PhoenixUSB has no Ethernet connection, Wi-Fi, storage or music-library software.
A music server, streamer or computer remains responsible for finding, decoding and playing the music.
Explore current network music streaming products where a complete source is required.
Not a Network Switch
The PhoenixUSB works on the USB connection between the source and DAC.
The related Innuos PhoenixNET was designed for the Ethernet network connection instead.
The two products address different parts of a streaming system and are not substitutes for one another.
PhoenixUSB or PhoenixNET?
Choose PhoenixUSB When
- The source sends audio directly to a DAC through USB
- You want to regenerate and reclock the USB connection
- The DAC relies on USB for its digital input
- A clean 5V USB line is useful
- The network connection is already performing well
- Remaining PhoenixUSB stock is available
Choose PhoenixNET When
- The streamer receives music through Ethernet
- You want to improve the network connection
- The DAC is built into the streamer
- USB is not used between the streamer and DAC
- Several network audio products share one switch
- Remaining PhoenixNET stock is available
Standalone PhoenixUSB or PhoenixUSB Board?
Standalone PhoenixUSB
- Works with suitable Innuos and third-party USB sources
- Uses its own separate chassis
- Contains two independent linear power supplies
- Can remain in the system when the source is changed
- Requires two USB cables and a mains connection
- Now discontinued
PhoenixUSB Output Board
- Fits selected current Innuos streamers and servers
- Integrates the reclocked output inside the source
- Requires only one USB cable to the DAC
- Uses the host product’s internal power architecture
- Must be installed by an approved Innuos dealer
- Available with selected current Innuos models
The optional PhoenixUSB Board is available for products including the Innuos Stream1 and Innuos Stream3.
PhoenixUSB or a DAC Upgrade?
Consider the PhoenixUSB When
- You already own a high-quality DAC
- The source and DAC are connected through USB
- The overall system is already well balanced
- You want to retain the existing DAC presentation
- A demonstration shows a worthwhile improvement
- A suitable remaining unit is available
Consider a New DAC When
- The current DAC is the main system limitation
- You require additional digital inputs
- You need balanced or variable analogue outputs
- The DAC lacks the required PCM or DSD support
- USB compatibility is poor or unreliable
- The new converter provides a greater overall improvement
Browse DACs and digital-to-analogue converters at Audio T.
Where the PhoenixUSB Is Most Relevant
The PhoenixUSB is most likely to justify its place in a system where:
- The USB source and DAC are already of a high standard
- The system is transparent enough to reveal smaller digital-source changes
- The amplifier and loudspeakers are well matched
- Speaker positioning and room setup are already under control
- USB is the preferred connection to the DAC
- The listener intends to retain the existing source and DAC
Where Other Upgrades May Come First
A PhoenixUSB may not be the first priority where:
- The speakers are poorly positioned
- The room has major uncontrolled bass problems
- The amplifier struggles to drive the loudspeakers
- The DAC is outdated or unsuitable
- The streamer is unreliable or lacks required services
- The system uses optical, coaxial, AES or network playback instead of USB
- The available budget would fund a larger improvement elsewhere
USB Cable Selection
The PhoenixUSB requires a reliable USB data cable on each side.
The source cable must provide the correct host-to-device connection for the PhoenixUSB input.
The outgoing cable must connect the PhoenixUSB Type-A output to the DAC’s USB audio input.
A good cable should provide secure connectors, correct impedance and reliable data transfer without placing unnecessary physical strain on either socket.
Browse network and USB cables at Audio T.
Keep USB Cables Sensibly Short
Use the shortest practical cable lengths that allow the source, PhoenixUSB and DAC to be positioned without tension.
Very long passive USB runs may create connection and reliability problems.
Do not bend the cables tightly immediately behind the sockets or allow their weight to pull sideways on the connectors.
Troubleshooting a Missing DAC
Where the source no longer detects the DAC after the PhoenixUSB is installed:
- Reconnect the source directly to the DAC and confirm that it works.
- Check that the DAC is switched on and set to its USB input.
- Check the source playback output and driver.
- Confirm that the cables are connected to USB IN and USB OUT correctly.
- Try the USB cable supplied with the PhoenixUSB.
- Restart the source, PhoenixUSB and DAC.
- Remove any unapproved adaptors or USB isolators temporarily.
- Ask Audio T to test the PhoenixUSB with another source and DAC.
Testing the PhoenixUSB as a USB Hub
Innuos explains that the PhoenixUSB can be checked using a conventional computer and USB device.
Connect a PC or Mac to the PhoenixUSB input and connect a USB memory device to its output.
If the computer detects and reads the USB device, the PhoenixUSB’s basic hub operation is functioning.
This test does not assess sound quality or guarantee compatibility with every DAC, but it can help distinguish a reclocker fault from a source, cable or DAC problem.
System Placement
The PhoenixUSB measures 215mm wide, 342mm deep and 87mm high.
Its half-width enclosure makes it relatively easy to position beside an Innuos server, DAC or other compact digital component.
Allow additional rear space for the IEC mains lead and two USB cables.
Place it on a stable shelf and avoid stacking it directly on a hot amplifier or power supply.
Low Power Consumption
Power consumption is specified at approximately 3W while idle and 7.5W at peak.
The low consumption means that the PhoenixUSB produces relatively little heat, but it should still be given normal airflow and kept away from moisture.
Designed in England and Manufactured in Portugal
The PhoenixUSB was designed by Innuos in England and manufactured in Portugal.
Its internal technology was developed from the USB regeneration and power-supply work used within the Innuos STATEMENT range.
Finish Options
Black
The Black finish provides a discreet appearance and coordinates with black Innuos servers, DACs and other dark Hi-Fi components.
Silver
The Silver finish provides a lighter alternative for systems using silver or natural-aluminium equipment.
As the PhoenixUSB is discontinued, finish availability will depend on remaining stock and ex-demonstration units.
Innuos Products and Audio T Digital Guides
Key Features
- Standalone USB regenerator and reclocker
- Designed for use between a USB source and DAC
- Operates as a transparent USB hub device
- Completely regenerates the outgoing USB connection
- High-precision 3ppb OCXO master clock
- Direct 24MHz clock operation
- Short internal board-track clock connection
- No external 10MHz clock conversion required
- USB chip contains no switching regulators
- Three independent USB-chip voltage rails
- Three sets of LT3045 low-noise regulators
- Two independent linear power supplies
- Dedicated linear supply for the OCXO clock
- Separate linear supply for USB circuitry
- Clean 5V outgoing USB line
- Technology derived from Innuos STATEMENT
- Compatible with suitable Innuos USB sources
- Compatible with suitable third-party USB sources
- Compatible with USB DACs
- No music storage
- No streaming services
- No internal DAC
- No analogue output
- No network connection
- No control application required
- No front-panel power button
- Rear mains power switch
- USB Type-B input
- USB Type-A regenerated output
- USB cable included
- Low 3W idle power consumption
- 7.5W peak power consumption
- Half-width enclosure
- Black finish option
- Silver finish option
- Designed in England
- Manufactured in Portugal
- Discontinued but supported by Innuos technical service
Frequently Asked Questions
What is the Innuos PhoenixUSB?
It is a standalone USB regenerator and reclocker designed for installation between a compatible USB source and DAC.
Is it still a current Innuos product?
No. Innuos now lists the standalone PhoenixUSB as discontinued.
Does Innuos still support it?
Yes. Innuos states that its discontinued products remain supported by its technical service.
What does it do to the USB signal?
It receives the USB packets from the source and retransmits them through a new USB connection using its internal high-precision clock and linear power supplies.
Does it simply filter the USB power line?
No. It regenerates the USB connection and also provides a clean 5V line from its internal linear power supply.
What clock does it use?
It uses a 3-parts-per-billion oven-controlled crystal oscillator operating directly at 24MHz.
Why does it use 24MHz rather than a 10MHz input?
The USB chip requires a 24MHz operating clock. Generating that frequency directly avoids an external 10MHz connection and another conversion stage.
What is an OCXO?
It is an oven-controlled crystal oscillator that maintains its crystal within a controlled thermal environment to improve frequency stability.
Does it contain switching regulators?
The principal USB regeneration chip contains no switching regulators. Its three voltage rails are supplied from linear circuitry with further LT3045 regulation.
How many power supplies are inside?
Two independent linear power supplies are used, one for the OCXO clock and one for the USB circuitry and 5V line.
Is it a DAC?
No. A separate USB DAC is required.
Does it have analogue outputs?
No.
Is it a network streamer?
No. It has no Ethernet, Wi-Fi, streaming services or music-control app.
Does it store music?
No.
Can it rip CDs?
No.
Can it convert USB to optical or coaxial output?
No. It preserves the USB connection and provides only a regenerated USB output.
Can it be used with a non-Innuos source?
Yes. The source must provide a compatible USB host output capable of driving a USB DAC.
Can I use it with a computer?
Yes. A compatible Windows, Mac or Linux computer can be used as the USB host source.
Will I need a Windows DAC driver?
Where the DAC manufacturer requires a Windows driver, that driver remains necessary. The PhoenixUSB does not replace it.
Does it require an Innuos app?
No. The PhoenixUSB has no app or software configuration of its own.
Which USB input does it use?
The PhoenixUSB uses a USB Type-B input from the source.
Which USB output does it use?
The regenerated output is provided through USB Type-A.
How is it connected to a DAC?
Use a suitable USB A-to-B cable from the PhoenixUSB output to the DAC’s USB audio input.
How many USB cables are required?
Two. One connects the source to the PhoenixUSB and another connects the PhoenixUSB to the DAC.
Is a USB cable included?
Yes. One USB cable is included with the unit.
Does it limit the PCM sampling rate?
Innuos does not publish a separate conversion limit because the PhoenixUSB operates as a USB hub and reclocker. Playback capability depends on the source and DAC.
Does it support DSD?
It can remain in a compatible USB connection carrying DSD, provided the source, software, driver and DAC support the selected format.
Does the DAC need the USB 5V line?
Many DACs require the 5V line to initialise their USB interface. The PhoenixUSB provides a clean 5V supply on its output.
Can I use a USB cable with the 5V line disconnected?
Only where the DAC manufacturer confirms that its USB interface does not require the 5V line.
Does it have a front power button?
No. Power is controlled by the rear mains switch.
Does it have a front operating light?
No.
Can it be left powered on?
Its idle consumption is low, but owners should follow normal electrical safety guidance and switch it off before changing cables or leaving the system unused for an extended period.
How much power does it consume?
Innuos specifies approximately 3W while idle and 7.5W at peak.
What are its dimensions?
It measures 215mm wide, 342mm deep and 87mm high.
How much does it weigh?
It weighs approximately 5kg.
Which finishes were produced?
Audio T lists Black and Silver options, subject to remaining availability.
Where was it manufactured?
It was designed in England and manufactured in Portugal.
What is included in the box?
The PhoenixUSB, mains cable, one USB cable and getting-started guide are included.
Should I choose PhoenixUSB or PhoenixNET?
Choose PhoenixUSB for the USB connection between a source and DAC. PhoenixNET was designed for the Ethernet network connection.
Should I buy a PhoenixUSB or upgrade my DAC?
That depends on the system. A DAC upgrade may provide the larger improvement where the existing converter is the principal limitation. A PhoenixUSB is most relevant where the source and DAC are already of a high standard.
How can I confirm that it is working?
The source should detect and play through the DAC as normal. Innuos also suggests testing its basic hub operation with a computer and conventional USB device where troubleshooting is required.
Why Buy From Audio T?
- Demonstrations within a suitable high-quality digital system
- Advice establishing whether USB reclocking is appropriate
- Source and USB DAC compatibility checks
- Comparison with direct USB connection
- Advice choosing between PhoenixUSB and PhoenixNET
- Current Innuos streamer and server guidance
- PhoenixUSB output-board advice for selected Innuos products
- USB cable and connector matching
- DAC driver and USB Audio Class guidance
- Remaining-stock and ex-demonstration condition checks
- Black and Silver finish availability checks
- System placement and cable-routing guidance
- Part exchange may be available on suitable existing equipment
- Ongoing setup and troubleshooting support
Contact your local Audio T store to check PhoenixUSB availability or arrange a demonstration within a suitable source and DAC system.