Phil Jones Bass X4 NanoBass Combo review

How does a bass amp featuring nanotechnology size up? Not too badly as it goes, with Phil Jones making the most of an improbably small format

Phil Jones Bass X4 NanoBass
(Image: © Phil Jones Bass)

Guitar World Verdict

An amp the size of a shoebox shouldn’t sound this good – but it does.


  • +

    Fantastic tone.

  • +


  • +

    A tiny package.


  • -

    Awkward plug angle.

  • -

    Lacks a direct output.

  • -

    Innovation comes at a price.

You can trust Guitar World Our expert reviewers spend hours testing and comparing guitar products so you can choose the best for you. Find out more about how we test.

Amp designer and mad scientist Phil Jones has built a reputation for getting a big sound out of small speakers, but there’s usually more than one of them in his products. His latest creation is the multi-instrumental X4 Nanobass, which his company calls the most compact and portable combo he’s ever designed. 

The unit features a single four-inch driver in an enclosure that measures 6.3” by 7.9” by 7.8” and weighs just 5.3 pounds. Billed as the perfect bass amp for your desktop or on the go, it has a headphone jack for silent practice and, crucially, two options for playback from external sources.

A 1/8” jack lets you manually plug in, while Bluetooth capabilities let you stream from  the mobile device of your choice. An independent level knob allows for setting the output from either external source you choose. Last in its control set is a three-band EQ for tone shaping.

Phil Jones Bass X4 NanoBass

(Image credit: Phil Jones Bass)

Even at its diminutive size, the X4 feels very sturdy. The AC input, which accepts worldwide voltage, is situated on the bottom right side of the amp, leaving the right-angled plug to stick out about one inch.

This must be a factor of fitting so much into a tiny space, but it does make it more awkward when sitting on a tight desk. All of the controls are very straightforward, and connecting to the Bluetooth is as simple as one push of the aux-in level knob.

Sound and performance

As is evidenced in the owner’s manual, Jones and his team of wizards have spent lots of time and resources to design the X4. I’m here to tell you that it worked. The sound is clean and clear, even articulating a low B-string very nicely. 

Ultimately, the X4 is a convenient practice tool that sounds great, and having a great sound is a key to inspiration in your practice sessions.

Its low end reflects your instrument’s voice, but goosing the bass knob adds a surprising amount of heft and warmth. At 35 watts, it won’t compete with drums, but it certainly hangs with acoustic jams.

Mostly I found myself using it as a quick tool to jam with music and drum apps. I may be greedy, but I would have liked to see it have a direct output, seeing as it sits right at your workstation.

Ultimately, the X4 is a convenient practice tool that sounds great, and having a great sound is a key to inspiration in your practice sessions. At $360, there’s a price for convenience, but it’s an investment to have your tone in a combo you can bring anywhere.


  • Price: $359.99
  • MADE IN: China
  • POWER: 35 watts
  • SPEAKER: 1 x N52 Neo-Power 4” speaker driver
  • FEATURES: Digital power amp with DSP-based active crossover and dynamic range control, three-band EQ, 1/8” stereo Aux input, Bluetooth 5.0 (aptX HD), Aux/ Bluetooth level control, headphone output, worldwide AC voltage input (100-240V) 
  • WEIGHT: 5.3 lbs
  • CONTACT: Phil Jones Bass

Thank you for reading 5 articles this month**

Join now for unlimited access

US pricing $3.99 per month or $39.00 per year

UK pricing £2.99 per month or £29.00 per year 

Europe pricing €3.49 per month or €34.00 per year

*Read 5 free articles per month without a subscription

Join now for unlimited access

Prices from £2.99/$3.99/€3.49