Fender Adam Clayton ACB 50 review – Fender’s first-ever signature bass amp is a greatest hits of all-tube tones

Designed in conjunction with U2’s Adam Clayton, the ACB 50 is Fender’s first all-tube bass combo amp for over four decades – we put it through its paces

Fender ACB 50
(Image: © Fender)

Guitar World Verdict

One for tube tone purists, this high-end combo conjures up some of Fender’s most sought-after bass tones.


  • +

    Classic Fender tube sounds.

  • +

    Simple yet sensibly designed controls.

  • +

    Super-cool looks.


  • -

    Not much clean headroom.

  • -

    Pricey (but it is tube).

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Earlier this year, Fender launched its Adam Clayton signature bass amp, marking nine years since the company first got involved with U2’s stadium-rocking bassist with the Adam Clayton Jazz Bass.

The ACB 50 is the first all-tube bass combo amp Fender has produced in over four decades. “I know the fashion nowadays is to move away from valve amps, but I’ve always liked them,” said Clayton. “So I went to the team at Fender and asked if we could approach things a little differently.”

We love all sorts of amps here at Bass Player, but there’s something about a cranked-up tube combo that really tugs at our heart strings. As its name suggests, the ACB 50 is rated at 50 watts. As such, it should be well-equipped to handle rehearsal duties, smaller gigs and recording sessions. It’s styled on a tried-and-tested Fender recipe – an aged silver sparkle grille cloth, chickened knobs, and black textured vinyl, but does it have the tone to match its good looks? 

Fender ACB 50

(Image credit: Fender)


The Fender ACB 50 is a dual-channel tube combo. The preamp section is driven by a 12AT7 tube and a trio of 12AX7 tubes – easily the most popular preamp tube for guitar amplification. Moving onto the power section, the amp’s signature tone is derived from two 6L6 tubes. The semi-open-backed cabinet has a steel grille to protect the vulnerable tubes from external objects (not to mention protecting sensitive fingers from hot glass).

Looking at the top-mounted chrome control panel, channel one has a volume control, and a conventional bass, middle and treble EQ section. Where things get a little interesting is with the mid-frequency rotary switch, which boosts three midrange frequency settings via the middle control.

The second channel has an identical setup, but with a bass and treble EQ section only. Both channels offer dual inputs, with the second input designed to offer less sensitivity (-10db) to compensate for active instruments. 

In general, the build quality and finishing are up to the usual standard you’d expect from Fender. The cabinet feels solidly built, with the hard-wearing textured covering and a chunky leather handle adding to its road-worthy appeal.

The internal speaker is a 15-inch Eminence Neo speaker. This should be more than adequate for most applications, but there’s also scope to attach an external speaker cab too. Round the back of the amp there’s a single speaker-out jack, a balanced XLR out with a ground lift switch, a quarter-inch line out for recording and PA connection options.


We tested the ACB 50 using a range of bass guitars, including a Fender Precision, a Dingwall NG3, a Gretsch Electromatic Jr, and many more besides. Many more than usual, in fact – though we’re always thorough when reviewing gear, this amp sounded so good that we felt compelled to plug in and play every bass that we could lay our hands on!

With some bass amps, you’ll find that the amount of perceived break-up increases as you turn up the volume, and you only hit that full sweet spot once the walls are shaking and the amp’s really cooking. Not here, though – the ACB 50 slips smoothly into increasing levels of saturation – there’s loads of the stuff. Even with the volume kept back you can tell it’s just longing to break up. If you’re a fan of the rougher-edged tones of Adam Clayton, then you’re in for a treat here. Even in the cleaner range of the volume controls, there’s a wonderful sense of sustain and fatness.

According to Fender, Channel 1 has been voiced as a vintage Fender ‘black panel’ preamp tonality – in other words, it’s designed to offer a more vintage tone in keeping with Fender amps of the ‘60s. You can shape the airy mid frequencies via the mid-frequency control, adding more aggression to the upper midrange, though things can get a little edgy if you push it too far.

Seconds after plugging in, we were getting comments from other band members about how great it sounded

Channel two bypasses the mid boost and lets you enjoy the natural sound of the amp. It’s not quite as ‘hi-fi’ as some modern bass amps, instead sounding rather grittier, but for a flatter EQ tone you might prefer to stay here. Unfortunately, this channel’s ‘less is more’ approach doesn’t extend to background noise, though this is of course not noticeable until you stop playing.

We say this genuinely and without hyperbole, but on the first two gigs that we used this amp, seconds after plugging in, we were getting comments from other band members about how great it sounded, and if that doesn’t put a big smile on your face, then you should probably just pack it in and take up knitting.


The fact that we’ve been so busy talking about the sound of the ACB 50 that we’ve mentioned only in passing how very cool it looks tells its own story. It might not be hugely powerful or particularly versatile in the accepted sense of tone-shaping niceties, but viewed purely as a low volume amp for low-key gigs and recordings, it will comfortably cut through, so long as you don’t overestimate its ability to cope cleanly with larger stages or louder bands. You could always mic it up if you’re not quite reaching the back of the room.

What about the price? $2,199 is a lot of money however you look at it, and a lot to pay for an amp that’s something of a specialist tool. The ACB 50 essentially does one thing very, very well, but if the sound of a vintage-style, all-tube circuit cranked up loud is the sound you want, this could be the amp for you.

Fender ACB 50

(Image credit: Fender)


  • PRICE: $2,199
  • MADE IN: Mexico
  • TYPE: All-valve combo
  • OUTPUT: 50 watts into 8 ohms
  • VALVES: 2x 6L6 power tubes, 3x 12AX7 & 1x 12AT7 preamp tubes
  • CHANNELS: Two, classic Fender sound & flatter frequency sound, each with high & low inputs.
  • FEATURES: Channel one with volume, treble, bass, middle & mid frequency controls, channel two with volume, treble & bass controls. Balanced direct out, ground lift switch, balanced line out & external speaker out.
  • SPEAKER: 1x 15-inch Eminence Special Design
  • WEIGHT: 25 kg (55lbs)
  • DIMENSIONS: 61.5 (w) x 58.4 (h) x 35.6 (d) cm
  • CONTACT: Fender 

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Nick Wells

Nick Wells was the Editor of Bass Guitar magazine from 2009 to 2011, before making strides into the world of Artist Relations with Sheldon Dingwall and Dingwall Guitars. He's also the producer of bass-centric documentaries, Walking the Changes and Beneath the Bassline, as well as Production Manager and Artist Liaison for ScottsBassLessons. In his free time, you'll find him jumping around his bedroom to Kool & The Gang while hammering the life out of his P-Bass.