The near-universal popularity of Boss’s Katana range shows no sign of slowing down, with a full range of affordable digital amplification covering every need – from big stages and arenas, to pubs, and the home.

The latest product to bear the Katana name, the Katana:Go headphone amplifier, is the smallest yet and likely to become another success story for Boss.

The Katana:Go is small enough to fit in your pocket and exquisitely designed, with the same attention to detail lavished on all Boss products. As you might expect, it’s not exactly bristling with knobs and switches, and yet the various small buttons and volume-control wheel handle everything you might need, and they’re intuitive to use so after a while you don’t really need to look at them any more.

On the lower side, from a plugged-in perspective, you’ll find an on/off switch with a charge indicator LED that glows red when the battery is low, amber when charging, and green when fully charged. Two more button switches manage the Katana:Go’s Bluetooth connection and a Stage Feel 3D ambience effect.

On the opposite side, nearest the player when plugged in, there’s a Bank Up/Down switch that also operates the tuner, together with three patch selection buttons labelled A, B and C. On the top face is a small monochrome display and the volume control, with a 3mm stereo jack socket for your headphones and a USB-C socket on the back face.

The integral jack plug is hinged and folds to accommodate angled and straight jack sockets, covering practically all guitars. Thoughtful soft pads on the underside protect your guitar’s finish.

The key to the Katana:Go’s power is software, rather than hardware.

A specially designed version of Boss’s Tone Studio app connects via Bluetooth and lets you access the five famous Katana voices, each with a second variation. EQ controls include Bass, Middle, Treble, Presence and Cabinet Resonance, this last one with a choice of Deep, Vintage and Modern modes.

There are dozens of effects to choose from, covering all the bases you might need in the overdrive, distortion, modulation, delay and reverb departments, plus seven different signal chains to arrange them in.

There’s also not one but two parametric EQs and a noise gate, with yet another global EQ lurking in the system settings. The Katana:Go also unleashes 3D audio in its clever Stage Feel mode, which gives you the impression of playing in a room, either in a hall or a studio, with your virtual amp in front or behind, plus a custom setting you can tweak.

You can use the Tone Studio’s Session List feature to load and play music from your mobile device or YouTube, and arrange songs in your favourite order, as well as assigning your favourite patches to play along with them.

Roland account holders can make full use of the Boss Tone Exchange to browse and download from thousands of Liveset patches uploaded by users from all over the world; the Katana:Go is compatible with Livesets created on the Mk1 and Mk2 Katana amps.

Are we finished? Nowhere near. This feature-packed device also offers high‑quality USB streaming and recording to your mobile device or desktop, is compatible with the Boss wireless expression pedal and footswitch, and operates in either Guitar or Bass mode.

The Katana:Go’s onboard memory holds 30 patches (or 60, if you count the bass mode) that are arranged in 10 banks of three. Soft-touch button switches on the side nearest the player scroll through the banks and select the individual patches, with a useful tuner function if you push in the Bank Up/Down switch.

In guitar mode, you can pick or choose from Acoustic, Clean, Crunch, Lead or Brown amp voices, each with a variation and a regular EQ layout. Swapping into bass mode gives you a choice of bass-optimised Vintage, Modern or Flat amp voices, each with a Shape option, while the amp EQ defaults to a semi-parametric configuration, with swept low and high mid controls and shelving treble and bass.