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Peavey ReValver 4

Guitar Amp & FX Modelling Software By John Walden
Published April 2017

Peavey ReValver 4

The latest iteration of Peavey’s modelling software not only allows you to build your own virtual guitar amps, but to ‘profile’ real ones.

Guitar amp modelling is a technology that now has a long history. Whether it’s done using dedicated hardware such as modelling amps, racks or floorboards, or in software, modelled guitar tones can now be utterly convincing. Players have strong personal preferences in terms of tone and feel, but from the listener’s perspective — even that of a well-informed and critical listener — when those tones hit you from your studio monitors, PA speakers, hi-fi or ear-buds Well, there are lots of interesting A/B blind tests you can now find on YouTube if you want to test your own abilities to tell the difference between a real amp and a modelled version of the same amp.

Peavey’s ReValver is one of the many native software-only modellers, and has been around for some time — Paul White looked at ReValver 3 back in the May 2009 issue of SOS. The new ReValver 4 is a free download, and although you only get a relatively small amount of virtual kit for nothing, an impressive selection of virtual amps, cabs and effects can be added with the modestly priced Producer Pack.

ReValver 4 is installed as a stand-alone program and in VST, AU and AAX plug-in versions, on Mac OS and Windows. Installation is simple enough, but does require a USB device to store a licence key: I used my iLok, but any USB device can be used. The free version includes only a few ‘lite’ amps, cabs and effects, but the full set of virtual equipment is accessible via a demo mode, so you can give the ReValver 4 experience a pretty thorough workout before buying. The built-in Amp Store allows you to buy items once you are ready to commit. Amps, cabs and so on can be bought individually, but also in bundles, and for this review, I explored what is perhaps the best-value bundle: the ReValver 4 Producer Pack. Peavey also provided me with a few other extras to try out, notably some of the ACT (Audio Cloning Technology) add-ons.

Fully Stacked

The Producer Pack bundle opens up an impressive collection of virtual equipment including a diverse selection of amps.The Producer Pack bundle opens up an impressive collection of virtual equipment including a diverse selection of amps.I spent most of my time with the VST plug-in running within Cubase 9, but also gave the stand-alone version a spin. This would, with suitable hardware and audio connectivity, allow you to use ReValver 4 in a ‘performance’ context in the studio, rehearsal room or on stage. There is a ‘gig’ mode that offers features tuned for that context, including eight user-defined presets and MIDI switching with suitable MIDI hardware. This mode also includes a global EQ option to shape all presets to the acoustics of the performance space.

In other respects, the stand-alone and plug-in versions are similar, and are built around a number of ‘modules’. There have been some changes since Paul’s ReValver 3 review. For example, you now get Input and Output modules (I’ll come back to these later) and then three ‘slots’ called Stomps, Amps & Cabs and Effects, into which you can place individual modules. In fact, you actually get six such slots, as there are two parallel signal paths, allowing you to build two separate rigs, either for blending or creating a more pronounced stereo image. In both pathways, the signal order follows the same sequence of Stomps, Amps & Cabs and Effects, reflecting how a real guitar rig is constructed.

The Stomps section UI is now built around a visual representation of a hardware pedalboard that simply expands as you add more items. The Stomps section UI is now built around a visual representation of a hardware pedalboard that simply expands as you add more items. The Producer Pack provides a pretty varied selection of equipment. As you might expect, the amps and cabs are dominated by some Peavey favourites, but there are also thinly disguised models of other brands including Marshall, Orange and Vox. The cab modelling is based upon impulse response technology, in both full and ‘lite’ versions, the latter being less demanding of CPU resources. You also get a choice of virtual mics, options for mic placement and ambience/filter controls.

The Stomps section covers all the usual options, including overdrive, distortion, compression, modulation, wah and reverb, and is now presented as a virtual pedalboard that simply expands as you add more modules. The pedalboard UI is pleasing to look at, but occasionally requires reading glasses to decipher some of the control labels!

The Effects section delivers a more ‘post-amp’ rack-style view, with options including the rather nice Again Delay, a graphic EQ and the World Wide Verb. ReValver also offers a module that can be placed in the Stomps, Amps & Cabs or Effects areas for hosting third-party VST or AU plug-ins, which obviously opens up all sorts of further creative options.

The Effects section is presented rack-style and, as shown here, can include the ACT Rack EQ module as an extra add-on.The Effects section is presented rack-style and, as shown here, can include the ACT Rack EQ module as an extra add-on.Peavey have provided a huge number of presets, which most certainly demonstrate the versatility provided by this combination of virtual equipment, and include some intended for bass and acoustic guitar. As with any native virtual guitar rig, you need to make sure that the DI’ed guitar input you are using is of a suitable quality (a high-impedance input on your audio device or a dedicated DI box, for example) but, with that in place, ReValver 4 does, indeed, sound very good. I found myself doing the usual preset tweaking to find exactly what I wanted, but the bottom line is that, through my studio monitors, ReValver 4 was more than capable of delivering the goods, whether that’s sparkly cleans, head-crushing gain or something in between.

Better Than The Real Thing?

Top-end hardware modelling devices such as the Kemper Profiling Amp, BIAS Head, Fractal Audio Axe-FX, Amplifire and Line 6 Helix (amongst others) are drawing increasing numbers of professional guitar players in thanks to their tonal flexibility, practicality and sound. But are they as good as a real amp? That’s the question, and it’s one that will only become more interesting when Line 6 release their newly announced native software version of the Helix hardware unit.

Right now, I’d take my Helix over any of the native software solutions I’ve tried, ReValver 4 included. It has a responsiveness that I’ve not yet quite felt when using a software-only solution. Equally, while I’m a huge fan of guitar rig modelling technology, I also love the sound of a tube-based amp and, as a performer, I still prefer the interaction that amp, guitar and fingers seems to provide. There is a subtle but, to many, real difference. All that said, through my studio monitors, ReValver 4’s tones can sound absolutely great, whether isolated or within a mix. I’m still not 100 percent sure that the performance experience is quite the same but, sonically, I suspect that the vast majority of listeners — including guitar players — would find it pretty difficult to hear the difference in a recording context.

I’m not sure quite how many guitar players might wish to turn up to a gig with just ReValver 4, their laptop, and a suitable audio interface just yet. Guitarists are still, in the main, a pretty conservative bunch. However, dedicated hardware modellers are slowly gaining some traction here so maybe native software will follow?

The studio is another matter, though. Like all guitar rig modelling packages, ReValver 4 offers a vast range of tonal possibilities. Equally, like the competition, the current incarnation of ReValver 4 is streets ahead of where software/native-based guitar amp modelling was five or more years ago. I like the changes Peavey have made in the UI for this version, and the ACT technology shows considerable potential, although the amp profiling process does require a bit of work to fully exploit. In a mix, ReValver can sound very convincing and the ease with which you can dial in almost any tone — and re-dial it after the fact — is a big benefit for the studio user. Add in the cost and convenience factors and ReValver 4 is undoubtedly a very tempting proposition for the studio-based guitar player.


The obvious software competition to ReValver 4 comes from products such as Native Instruments’ Guitar Rig 5 Pro, IK Multimedia’s AmpliTube 4, Scuffham’s S-Gear 2.5 and Positive Grid’s BIAS FX and BIAS Amp. The last of these is Positive Grid’s take on building your own amp design, while all the other products offer the complete virtual guitar rig experience combining amps, cabs and effects. All come fully stocked and, frankly, sound great.

Additionally, by the time you read this, Line 6 may also have added Helix Native to the options and, although this may well be more expensive, it appears it will offer all the modelling options of the highly regarded Helix hardware unit in a native software format.

A Class ACT?

A big selling point of ReValver 4 is a paid-for add-on that Peavey describe as Audio Cloning Technology, or ACT, which fulfils several different roles within the software. It is built into both the Input and Output modules, and if you are prepared to pay for the additional modules, you can also access the ACT Combo Tone Matching module ($39.99) and the ACT Rack EQ module ($19.99). All of these ACT elements offer something different.

Within the Input module, you can capture the sound of your DI’ed input signal. Then, using ‘profiles’ captured by Peavey from a range of classic electric and acoustic guitars, the ACT technology will transform your input sound into the chosen profile sound. You can, therefore, transform your own single-coil guitar input into, for example, a humbucker-based guitar — or, potentially, an acoustic guitar. A few profiles are supplied as standard, and plenty more are available within the Amp Store. In the Output module, the ACT technology provides EQ shaping. Again, a range of ‘classic’ guitar tones have been profiled, and presets can be applied to push your own tone in the direction of the profiled tone.

The ACT Combo Tone Matching module is, in concept, very similar to the amp profiling available in hardware such as the Kemper Profiling Amplifier or BIAS Amp’s Amp Match feature. This allows you to ‘capture’ the sound of a real amp within the module; ReValver will then attempt to ‘match’ that tone using its various modelling options. The matching process uses a combination of a special test tone, which you have to replay through your amp, and your actual guitar tone as you play. The process requires a little bit of audio routing to complete, but nothing most diehard SOS readers should find too challenging. The end result is an ACT Combo profile that, in theory, should replicate the tone of your real amp.

The ACT Input Shaper can try to transform your input instrument. Les Paul to nylon acoustic anyone?The ACT Input Shaper can try to transform your input instrument. Les Paul to nylon acoustic anyone?The ACT Rack EQ module, which can be used within the Effects section of ReValver, provides a matching EQ option not unlike that offered by Voxengo’s CurveEQ. This allows you to apply the frequency response of a sound you want to replicate to a ‘target’ sound. The profiling process is fairly straightforward, and you can also control how far the matching EQ is blended into the target sound, as well as applying some smoothing to the EQ profile.

All these various ACT modules are based upon some pretty clever technology, and open up a huge range of potential tone options. I had no issues using the ACT Rack EQ, and found it easy to get good results. The ACT options within the Input module also work well providing you are attempting something that wasn’t too big a leap. For example, converting a single-coil guitar into a humbucker (or the other way around) produces very usable results. However, don’t expect to transform your Les Paul into a Martin acoustic with any great conviction; unless you are very lucky, the artificial nature of the transformation is generally pretty obvious.

The ACT Combo add-on module provides a DIY ‘amp profiling’ option.The ACT Combo add-on module provides a DIY ‘amp profiling’ option.My results with the ACT Combo were intriguing, but suggested that this is a process that does require some experience and experimentation to get the best from. I tried to profile my own studio tube amp (a Blackstar HT20) and, while I was able to get close, I’m not sure the fidelity of the modelled profile really matched that of the original. Equally, the playing experience through the profiles I created didn’t really match that of the real amp. However, there are a selection of ACT-based amp profiles available in the Amp Store that are considerably better than my own attempts, so perhaps profiling an amplifier requires a skill level that the review period didn’t allow me to achieve.

Soldering In Software

ReValver 4 allows the user to tweak individual components of a module without any danger of death by electrocution.ReValver 4 allows the user to tweak individual components of a module without any danger of death by electrocution.ReValver 4 retains the ReValver 3 option to tweak the design of modules by changing some virtual components. This is great for the real tone-geeks but I’m not sure the user interface — which is based upon some genuine schematic diagrams that pop up within the display — provides the most user-friendly of experiences.

The obvious comparison here is with the approach now offered by Positive Grid’s BIAS Amp software, both on desktop and iOS, where you get a much more user-friendly graphical interface for the same underlying process. With BIAS Amp now offering competition, this might be an area that Peavey need to rethink when the next major iteration of ReValver appears.


  • Free to try, and the Producer Pack offers excellent value.
  • Sounds great, with a huge range of tonal options.
  • There is considerable potential in the ACT features.


  • Graphics on some modules are quite small.
  • Amp profiling has potential but requires some practice.


ReValver 4 sounds great, and although software might not provide the same performance experience as a real amp or a top-end dedicated hardware unit, Peavey’s offering certainly delivers in terms of flexibility, convenience and value for money for the studio user.


Free. Producer Pack $99; add-on modules from $2.99; upgrades from $49.99.

Free. Producer Pack $99; add-on modules from $2.99; upgrades from $49.99.

Test Spec

  • Peavey ReValver 4.
  • Apple iMac with 3.5GHz Intel Core i7 CPU and 32GB RAM, running Mac OS 10.12.2.
  • Soundcraft Signature 12MTK.
  • Tested with Steinberg Cubase Pro 9.0.1.