Zoom UAC-232

Can Zoom’s new 32‑bit floating‑point interface banish clipping forever?

The benefits of 32‑bit floating‑point audio are most valuable in unpredictable recording environments, so it’s no surprise that this format was first implemented in field recorders. The basic idea is that the input signal is fed to two A‑D converters, which are aligned to different preamp gain ranges. No matter what input signal is fed in, one or other of them will capture it without overloading or introducing noise. In essence, a 32‑bit A‑D converter is ‘unclippable’, which is a very useful quality in a device that might be recording Formula 1 cars one day and birdsong the next.

Zoom are one of several manufacturers whose portable recorders support 32‑bit recording, and they’ve now introduced what they say is “the first dedicated 32‑bit float audio interface”. The UAC‑232 is a portable, bus‑powered stereo audio interface that connects to a macOS, Windows or iOS/iPadOS host over USB, and as long as your DAW supports 32‑bit floating‑point audio, should eliminate converter clipping as a problem in computer audio recording.

Corner Capers

The rectangular form factor of the UAC‑232 is familiar from many other small USB audio interfaces such as the Focusrite Scarlett Solo, but is disrupted by metal bars that stick out parallel to each corner and allow the unit to be stood on its end if that’s more convenient. Zoom also include a couple of Velcro cable ties that can be used to tidy cables, secure the UAC‑232 to something, or hang it from a mic stand. In the latter role, the cable ties will stop it falling off a stand altogether, but won’t prevent it sliding downwards if it spots an opportunity, so it might have been more effective to integrate a threaded mounting socket into the case. Note also that the UAC‑232’s mostly plastic shell is quite lightweight, so a light tug on a cable is enough to pull it over if stood upright — and, unlike on Zoom’s F8, for example, the protruding bars at the corners offer no protection to the front‑panel controls.

On the front panel, you’ll find two combi XLR/jack input sockets. Both can accept mic or line‑level signals, and the leftmost can also be switched to a high‑impedance mode for DI’ing electric guitars. Phantom power is independently switchable for both inputs. A single headphone output on quarter‑inch jack has its own volume control, and there’s a larger one for the main outputs. These are on rear‑panel quarter‑inch jacks, which sit next to 5‑pin DIN sockets for MIDI in and out, a Kensington lock slot, and two USB‑C ports. One of these makes the data connection to the host and carries bus power, while the other allows an ancillary power supply to be added if you’re using the 232 with a tablet or phone. The review unit came with a Type‑C to Type‑A cable but not a C‑C one. Although it uses Type‑C ports, it’s a USB 2 device, as indeed are almost all USB audio interfaces....