Published On: Mon, Aug 18th, 2014

Two-Rock Coral 40W Combo Review

Is your search for tone and performance leading you away from the world of mainstream amps and into the mysterious territory of boutique circuits? Marcus Leadley finds out what the Two-Rock fuss is all about…

Description: Dual-channel valve combo with shared EQ, cascading gain structure and single 12″ Rola Celestion G12-65. Made in USA
Price: £2899
Contact: Coda Music – 01438 350 815 –

The Coral is the newest version of what Two-Rock refers to as a ‘D-Style’ amplifier – a reference to the underlying influence of Alexander Dumble, who’s custom-built amps have been setting the bar for many makers since the notion of small-scale, handcrafted amp production took off in the 1980s. What this means is an evolution away from Fender tweed and blackface basics, though a process of modification, to a total redesign of the basic amp concept. At the core of the design we still have classic power valves (6V6s for the 22W and 40W models, 6L6s for the 50W and 100W), and there are head/cab and combo options to choose from.

The Coral 40W combo is a businesslike package. Decked out in black tolex with white trim, it sports a single 12″ G12-65 Rola Celestion. As well as the standard IEC power socket and On switch the back panel features two pairs of extension speaker sockets (4 ohm and 8 ohm), an FX loop, a footswitch socket, and the overdrive channel’s reverb Send and Return controls. There’s also a Fixed/Cathode bias switch. Biasing controls the amount of power a valve dissipates relative to voltage applied to it, and the approach to biasing affects an amp’s performance and helps define its sound: for cathode biasing, think tweed Fender Deluxe, Champ and Vox AC30; for fixed bias amps, think Marshall 50/100W, Hiwatts and larger Fender blackface amps.

Having a switch adds versatility – a lower-power mode with a compressed feel that’s easy to overdrive, versus a higher-output option that seems less compressed but offers a tighter tone and more clean headroom.

Moving to the front panel, the tone stack (Treble, Middle, Bass) is relatively straightforward, but it has Bright/Mid/Deep boost switches. There’s also an EQ Shift switch: the ‘up’ position offers a lower-gain setting with extended midrange and bass designed with clean tones and plenty of headroom, while flicking the switch gives you a higher gain setting. There’s an EQ Bypass switch that allows you to skip a load of circuitry and get straight into the power section, and just for good measure there’s also a Presence control. Plenty of tone-shaping potential, then.

Two-Rock suggests you stop thinking about Ch1’s Gain control in terms of overdrive. They call it the ‘right hand bounce’ or dynamic control, so you can dial in more for more ‘push back’. Less gain equals a stiffer, dryer performance; higher settings create a more marked contrast between gentle and hard playing. The Coral has a cascading gain structure, with Ch1 feeding Ch2. When you switch to the OD channel the clean Gain and clean Volume still affect the output: the second channel Gain/Volume controls takes things further. Channels can be switched via the footswitch, which also features a tone Bypass that mirrors the function of the Bypass EQ switch on the front panel.


One of the first things that becomes clear is that the Coral is an extremely loud 40-watter with a very distinct personality, no matter what configuration you favour. The bass leaps forward and grabs you by the ankles. It’s the sort of low-end response you’d normally associate with a larger head/cab or a 4×10″ Fender Bassman, and yet Two-Rock has managed to engineer it into a relatively small package. While the low end is a stand-out feature, the singing highs and clear mids are equally impressive. I’ve encountered the G12-65 under other circumstances, but I’ve never heard this degree of full-frequency articulation.

Starting clean with the bias set to Fixed, and EQ Shift in the up position, winding up Ch1’s master and then gradually bring up the gain gives a richly-detailed, fairly dry voice that’s very even in terms of playing dynamics: hitting harder doesn’t change the sound, it just gets bigger. Set up in this way, the amp gets very loud before it starts to break up. Running hot, it’s a big sound with a pleasing bluesy edge.

Before kicking over to the OD channel, you can influence distortion and crunch in a number of ways. Flicking the EQ shift switch loads on a controllable amount of gain while fattening up the sound. To ramp up the action further, hitting the EQ Bypass takes the gloves off, and the unimpeded amp is well-voiced in a full, fat and aggressive way. It’s a balanced sound, but, by its very nature, it’s not one you can EQ without recourse to the guitar’s controls or an external processor. Switching to Cathode Bias is very subtle, but it brings on distortion at lower Volume/Gain settings.

Although Two-Rock describes the Coral as a dual-channel amp with a shared EQ and cascading gain structure, they also call the Overdrive section an extension of the clean channel, so think of it as a very flexible single-channel amp with an added gain stage. Where channels are discrete, you can set up quite different rhythm/clean and lead/driven voices; here, you take one voice and then make more of it. Each approach has its advantages, and players looking for tonal consistency will favour the Coral. By engaging overdrive and then manipulating both sets of Gain and Volume controls you can create an almost infinite range of driven rock/blues sounds, from bright chime with a hint of grit to a wailing lead tone, or any point in between.

The reverb adds an extra touch of class. Situated before the Master Volume, it’s still mixed in parallel but it allows for a lot quieter performance and is arguably richer and lusher too. It’s a design feature that first appeared in the Crystal and John Mayer signature amps. The Send and Return controls mean you can create short, tight reverbs or expansive, lush textures, and the separate control for the Overdrive channel means you can have a different reverb setting for solos. Cool.


This is an incredibly flexible guitar amp capable of generating a wide range of sounds with clarity, sustain and balance at its core. Not only would it be an ideal recording amp, but it’s simple enough in operation for day-to-day gigs and home playing. Find your ‘sound’ and you may never feel the need to stray. While the price may appear to be on the steep side, good vintage Fenders and Voxes can cost you this and more. For valve lovers, the Coral offers a level of sonic perfection in a contemporary, manageable and reliable package.



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