Origin Effects RevivalDrive

This ambitious overdrive promises to recreate the entire signal path of a valve amp in solid-state electronics.

With their very first product, the Cali76, Origin Effects rewrote the rulebook for compressor pedals. The Cali's masterstroke was to take the UREI 1176 classic recording-studio compressor and recreate its circuit topology (the relationship between different components in the circuit) in a guitar pedal; using the same circuit layout or components as the 1176 would have been impossible in a 9V stompbox, but the Cali76 delivers remarkably similar characteristics.

Origin have now applied the same approach to overdrive. But rather than recreate a particular overdrive effect they've gone to the fountainhead of great guitar tone itself — the non-master‑volume guitar amps of the 1960s and '70s. Housing what's described as "an unabridged valve amp-style signal path recreated in analogue electronics", the RevivalDrive promises to serve up the sound of not just one amp but a whole host of British and American classics. Not content with this, the designers have also built in a range of controls to adapt the pedal's output to match the characteristics of the amp you're plugging into, with the aim of not only increasing the pedal's usefulness with different amps in the studio, but also allowing touring guitarists to get a consistent sound from night to night using whatever backline is available. With such an array of unique controls, the RevivalDrive is a serious proposition, with a serious price tag to match. Which begs the question, is it possible to OD on tonal options — or is this the last overdrive pedal you will ever need?

Channel Controls

The RevivalDrive's design is said to simulate the behaviour and interaction of every stage in a valve amp's signal path. This includes not just the usual suspects — the preamp, phase inverter, power amp and rectifier stages — but also a synthesized mains signal and a speaker-emulating reactive load. These last two are particularly important if the pedal is indeed going to capture the complex interplay between the power rectifier, the output stage and the speaker.

The pedal is entirely analogue, with discrete transistor-based circuitry standing in for the valve stages. The controls, which are identical across the Valve Rectifier and Silicon Rectifier channels, allow you to adjust key component values in the signal path, effectively redesigning the simulated valve amp inside the RevivalDrive as you go. For example, the Lows knob lets you adjust the amount of low end fed into the drive stage. At one extreme, with low frequencies bypassing this initial gain stage completely, you get an overdrive with a tight, clean bass response (think Vox AC30), while full bandwidth delivers fat, fuzzy lows (think Tweed-era Fender).

Similarly, the More/Pres knob controls negative feedback in the power amp. Turning it anticlockwise from the centre position reduces negative feedback, progressively changing the simulated amp's behaviour from something akin to a Class-A/B design (more headroom and a sudden shift from clean to distorted when you dig in with the pick) to a hot-biased Class-A amp (less headroom, more gain and a smooth transition from clean to distorted). Turned in the other direction, this knob behaves like a traditional Presence control, releasing the high frequencies from the damping effect of negative feedback and adding brightness and sparkle.

Another unique, amp-inspired feature is the Bright-Cap switch. In some amp designs, a capacitor placed across the volume pot allows high frequencies to sidestep any attenuation, thereby delivering a bright, sparkly sound even when the volume is set low. There are three settings here: Off, for no bright cap; the Fender-esque US mode, with just the highs escaping attenuation; and the GB mode, in which both mids and highs see maximum gain at all times. Said to mimic the late-'60s Marshall 1959 Super Lead circuit, this last option radically alters the behaviour of the volume control, which gets loud almost immediately then progressively adds more distortion.

Though the RevivalDrive notably does not provide a conventional set of bass/mid/treble EQ controls, there is a three-position preamp voicing switch with GB, US and neutral settings that applies a preset EQ curve. More unusual still is the Blend control, which allows you to mix your dry signal back in with the output of the overdrive, parallel compression-style. This is augmented by a Dry Gain control that lets you boost the dry level to match the overdrive. This is one of several mini pots in the centre of the densely packed control panel, and each can be adjusted with a flathead screwdriver or guitar pick. You can use your fingers too, though the pots can be stiff and hard to grip — but this does at least ensure that these controls won't be nudged accidentally.

The last control in the amp section is one of the RevivalDrive's USPs. The Ghost knob progressively reduces capacitance in the power supply, introducing what are known 'ghost notes' or 'double tones' — the dissonant, low-pitched notes that appear below the note you're actually playing when certain vintage amps are cranked very loud. As the power amp's filter capacitors (whose job it is to smooth out ripple in the direct current that's been converted from mains AC to DC by the rectifier) can no longer cope with the demands being placed on them, the frequency of the mains AC supply sneaks through and starts to interact with the frequency of the guitar signal, creating odd undertones.

We're entering rather esoteric territory here, but for some amp obsessives this is a significant ingredient of certain classic tones. The effect is rendered with great authenticity here, and though you can turn the Ghost knob right up to really exaggerate it for the most part, the result is a subtle thickening of single-note lead lines. I'm not aware of any other pedal that attempts to replicate the double-tone phenomenon, but Origin Effects have gone further still, adding a DIP switch at the rear that lets you set the simulated mains supply to either 50 or 60 Hz, mimicking the mains frequencies in the UK and US respectively, thereby altering the pitch of the tones produced.

Amp Compensation

It might seem like there's already quite enough going on inside this weighty and solidly constructed pedal, but the RevivalDrive has yet more in store in the form of its Re-Amp EQ section. According to Origin, this was specifically included to address the fact that most OD pedals — whether intentionally or otherwise — work better with some amps than others.

In addition to a three-way switch that provides preset EQ compensation designed to suit amps in either the Fender or Marshall mould or a flat-response power amp, the Re-Amp EQ section features two adjustable filters. The first ('Hi Shelf') is a shelving filter that lets you boost or cut the high frequencies by up to ±6dB to adjust for a darker or brighter sounding amp. The second ('Bri-Cap Cut') is a low-pass filter designed to counteract the treble-boosting behaviour of the bright caps in your amp.

If you decide to pony up for the Custom option, the RevivalDrive's Re-Amp EQ section is extended by an extra set of controls recessed into the front edge of the pedal. There are three-way switches to alter the corner frequency of the top-panel Hi Shelf and Bri-Cap Cut knobs, plus a whole extra tilt EQ control, again with a three-way centre frequency selector switch and a two-way mode switch that shifts the emphasis from taming brightness to adding clarity to a muddy-sounding amp.

Though I didn't find these controls immediately intuitive (for more studio-minded guitarists, some markings indicating corner frequency might have been helpful here), they are certainly very powerful and useful, and with reference to the manual and some experimentation by ear, it was possible to achieve exactly the desired result. In fact, testing the pedal with a variety of amps provides something of an education as to just how skewed the response of different amp designs is.

Rounding out the extensive feature set, the row of DIP switches at the rear does more than just switch the simulated mains frequency. You can also set the preamp voicing switch to continue shaping your tone when the effect is bypassed (though only when the Re-Amp EQ is set to feed a flat power amp) and change the Valve Rectifier channel into a second Silicon Rectifier channel.

The RevivalDrive's footswitch.Finally, mention should also be given to the built-in mid boost. This doesn't lift the mids going into the pedal's own OD circuit, thereby creating more distortion. Instead, the boost is applied at the output, helping the guitarist to cut through the band. This is made all the more useful by additional controls to adjust both the level and the centre frequency of the boost. A three-way switch lets you apply it to either channel, or turn it on and off independently using the optional footswitch, which also lets you remotely override the Dry Blend control.

Sounds

I'd read up extensively on this pedal before actually getting my hands on it, but even so a bit of experimentation was required to fully get my head around how all of the controls interact. With this experimentation it quickly became apparent that this is an incredibly flexible pedal. With the ability to control low-frequency distortion, set both the degree and biting point of breakup and shape the top end in a variety of ways, this is without question the most precisely controllable overdrive I've ever come across. And that's before you get to the Re-Amp EQ.

With this wealth of tone sculpting options — particularly if you go for the Custom version with its additional EQ — there's a danger that you'll end up chasing your tail, going back and forth between the channel and EQ compensation controls, with each change to one prompting further adjustment of the other. But with a little patience and discipline, and by trying the pedal with a couple of different amps, it shouldn't be too difficult to use it as intended, employing the channel controls to set the sound you want, then applying compensation to optimise for your amp.

If you were to pick one adjective to characterise the RevivalDrive, 'amp-like' would be a strong contender. Pick two, and 'uncannily amp-like' would fit the bill! For all its tweakability, and an impressive range of gain that goes from clean to fully cranked, this pedal is not going to replace the more way-out fuzz and drive pedals in your collection. As advertised, it is all about classic, deeply satisfying and resoundingly realistic overdriven amp sounds.

That realism is also seen in the behaviour of the Valve and Silicon Rectifier channels. As with the Ghost control, the difference is both fairly subtle and very accurate to the real thing. Players used to the exaggerated extremes encountered when flicking through modelling presets might be expecting more of a marked difference. And though the range of amp tones on offer here can rival many a modeller, they may also find that dialling in a sound takes a little more time and effort. The upside, besides the realistic sound and playing feel, is that, with such sensibly ranged controls, rooted in real amp behaviour, it's difficult to get a bad sound out of this pedal.

Conclusion

If I had one reservation before trying the RevivalDrive for myself it was whether the idea of a complete valve amp in a pedal (or at least a simulation of one), that you then plug into another valve amp, really made sense. Would that really be a useful thing or would they be treading on each others toes? Having now tried it for myself through a variety of amps in the Marshall, Fender and Vox vein, though, I feel both enlightened and comprehensively converted. These are amps I know well and hold in deep affection, but they have rarely sounded better. The RevivalDrive's ability to make them sound more like themselves — or the best version of themselves — as well as take on markedly different qualities is very impressive and, frankly, a lot of fun!

Though it's expensive (you could buy an entry-level valve combo for the same price) and it carries something of a learning curve, Origin's exercise in obsessive over-engineering has been worth the effort. It's a pedal that sounds and feels like an amp, both in terms of dynamics and wide-open frequency response, with none of the narrowed bandwidth typical of many pedal overdrives.

Whether you're adapting to dodgy backline on the road, sculpting the perfect tone in the studio or using the RevivalDrive as a front-end for direct recording, this pedal's greatest strength is its adjustability. If you've ever found yourself thinking, I really like this overdrive sound but it's just a bit too bassy, or too bright, or it's breaking up too early, then by hook or by crook this pedal will let you do something about it!