Home » Recording Resources » Featured Reviews » AUGUST 2019: Steinberg AXR4 Thunderbolt 2 Audio Interface

Steinberg hits hard with a well-connected, impeccably designed, high-resolution audio interface

Review by Paul Vnuk Jr.

Steinberg is one of the world’s premier DAW developers and it excels at audio interface design as well (check out the UR series). Steinberg is part of the Yamaha Corporation family, and its hardware line rides the mothership that makes Yamaha digital and analog mixers an industry standard. The AXR4 is not just another multi-channel DAW interface—it’s filled with cutting-edge technology that places it squarely in the high end of the professional converter and interface market. Let’s find out why.

Meet the AXR4

The AXR4 is a 28 x 24 Thunderbolt 2 audio interface. It features 32-bit integer converters that support sample rates up to 384kHz, as well as Steinberg’s new SSPLL (Super Suppression Phase Locked Loop) advanced virtual jitter reduction. Three AXR4 units can be chained and linked for increased channel count.

The AXR4 is housed in a standard 1U, 13 3/4” deep rack mount enclosure that’s totally jam packed with tech. Its brushed silver front panel is quite Euromodern looking! From left to right, we have four XLR jacks, the SILK controls (more on this later), a bank of six dedicated function buttons, a beautiful multi-function, full-color LED screen, a stepped push button encoder, a pair of independent 1/4” headphone jacks (each with its own super smooth volume pot), and finally, the master power switch.

Yamaha Preamps with the Rupert Neve SILK Touch

Front panel inputs are available on Neutrik XLR/TRS Combo connectors. Channels 1 and 2 accept mic/line/instrument inputs, while channels 3 and 4 are mic/line only. These inputs lead directly to all-new preamps—a hybrid design based on a combination of Yamaha’s super clean and neutral preamps (with +68dB of input gain), and a DSP model of SILK, the popular Rupert Neve-designed circuit that provides two modes of sonic enhancement: Red, for high frequency sparkle; and Blue, for thickness, boldness, and punch. SILK is dialed in to taste with a dedicated front panel encoder. Each preamp also has phantom power, a pad, a phase switch, and highpass filtering. In my work, I often preferred the harmonic excitement of SILK red and almost never turned it off.

Jam-Packed Back

On the rear of the unit are an additional eight TRS analog inputs,
labeled 5 through 12, and eight TRS analog outs. Digital connections are plentiful, with 8 channels of AES I/O carried over DB-25 as well as two pairs of ADAT Toslink sockets. The AXR4 has BNC word clock I/O as well as a pair of a pair of old school 5-pin MIDI jacks—cuz Steinberg is the venerable master of the MIDI sequencer!

Finally, we have a pair of Thunderbolt 2 jacks. Not to jump to any conclusions here, but these live on what looks like a removable interface card, so perhaps further connectivity options will be available in the future. Power is handled by an external line lump PSU.

Interface, Software and DSP

Some high end audio interfaces make use of a matrix-style routing app, while others utilize a software mixer. The AXR4 offers both—and they work seamlessly together.

The AXR4 mixer app appears as a full-on desk with faders, pan controls, channel linking, insert slots and an effect send. You can also access the preamp controls here, including the SILK settings.

The channel inserts call up the unit’s onboard zero-latency DSP effects. These are: Yamaha’s Sweet Spot Morphing Channel Strip, the Vintage Classics VCM Compressor 276, and the VCM EQ 601. Effects can be printed if you wish or simply monitored here. The effect sends route to the onboard Yamaha REV-X reverb, a long-standing company classic based on the popular SPX code.

If we stop here, the AXR4 is a professional DAW-agnostic interface, made to integrate with any major DAW from Ableton Live to Pro Tools.

Cubase/Nuendo Integration

Used with Steinberg Cubase or Nuendo, the AXR4 workflow becomes even more seamless. Input channels and DSP effects can be instantly routed and configured right in the Cubase mixer. Another direct benefit is the total integration of AXR4 32-bit integer converters with the native 32-bit Cubase environment. I am a Cubase user and found workflow with the AXR4 a breeze, so much so that I took it out of the studio and used it as both a live mixer and a tracking interface.

The Sound

As I often say in converter reviews, the bells, whistles and blinky lights are great, but a converter is only as good as it sounds—and, drum roll please—it sounds fantastic. In the past few months I have owned, used, compared and reviewed three of the industry’s top-rated converters, and the AXR4 stands proudly toe-to-toe with them all. I do not say this lightly; the AXR4 is that nice.

At this quality and price point, one might subjectively prefer the tightness of one, or the openness of another, but sonic integrity is never an issue. I do wish I could say that I hear a drastic difference between 24-bit and 32-bit integer conversion, but if I hear it at all, it’s not as drastic as the jump from 16-bit to 24-bit way back when.


Steinberg has come to the table with a seriously great-sounding, well-
designed, and feature-rich interface that can proudly stand as the centerpiece of any professional studio. If you’re a Cubase or Nuendo user, it’s even sweeter.

Price: $2799

More from: Steinberg, www.steinberg.net

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