Electronic Musician’s review of the Vox Tonelab, a desktop guitar amplifier modeling processor.

The field of desktop guitar-amp modelers has become quite crowded of late. It seems as though each new unit promises more emulations, more effects, more connectivity, and a lower price. Vox's new ToneLab — a direct descendant of the company's Valvetronix modeling amplifiers — takes a different approach. Instead of trying to outdo its competitors with sheer number of sounds, effects, and connectors, Vox has opted for superior quality. The ToneLab is designed to provide highly accurate emulations and to deliver real tube-amplifier reactivity between tone and player — undoubtedly the holy grail of modeling amp features.


The first thing you notice about the ToneLab is that it's not your average swirly-shaped, plastic-housed modeler. The solidly built unit is over a foot wide, with unpainted metal sides and bottom and a blue-metallic front, back, and top. Its array of chicken-head and vintage-style rotary knobs give it something of the look and feel of a classic amplifier (see Fig. 1). The gold-on-blue graphics are reminiscent of modern Vox amplifiers, and the staggered, diagonal knob positions give the unit a distinctive appearance.

Form follows function on the ToneLab; the left-to-right order of the dials and buttons corresponds to the unit's signal flow. The small display screen sits above ten programming and function buttons (actually called the Bank/Manual/Write/Tuner/Channel Selection buttons) at center right. In the top right corner, a clear plastic window gives a glimpse of the 12AX7 tube that powers the ToneLab's Valve Reactor power amp (which I will discuss further in a moment).

The two connectors on the front of the ToneLab are a ¼-inch stereo headphone out and a ¼-inch mono guitar-input. Both of these connectors are securely bolted onto the chassis and look capable of withstanding any amount of abuse.

The rear of the unit houses the remainder of its connections: Left/Mono and Right ¼-inch output jacks, an S/PDIF digital output, a Vox bus pedal-controller output jack, and MIDI In and Out jacks. There's also an output-level knob, a Line/Amp level selector switch, a Standby (power) button, and a ventilation port for the tube (see Fig. 2).

Although the level knob, switches, and buttons feel secure enough, none of the rear jacks are bolted to the chassis. No doubt this was done to conserve space and save money, and in fairness, the outputs shouldn't see nearly the amount of cable swapping that their front-panel counterparts do. Even so, I would prefer to have all the connectors bolted on.

I also wish there were a word-clock input, which would have made the digital output far more useful. As it stands, the S/PDIF output has limitations for professional applications, because unless your hardware offers on-the-fly sampling-rate conversion, the ToneLab must be the clock master, and it functions only at 44.1 kHz.


Operating the ToneLab is straightforward. The 13 rotary knobs on the face of the unit adjust the models and their parameters — there's no need to go digging in hidden menus to tweak your sound. The Pedal, Modulation, Delay, and Reverb effects sections share the same three knobs to control their adjustable parameters. (With the press of a button, you select which section's parameters are active.) A silk-screened chart above the knobs clearly shows which parameters are available for editing. Finally, there's a dedicated Tap button for programming delay time manually; this button also functions as an effects bypass when it's held down.

The ToneLab has 96 rewritable programs (48 of which are factory presets), broken up into 24 banks of 4. The programming and program-select buttons are in two rows of five buttons beneath the LED screen. The leftmost buttons let you scroll up and down through the program banks, and the four remaining buttons in the bottom row are numbered to let you choose a program from within the current bank.

The button scheme makes it easy to switch between programs within a group, but bank switching — especially if you're switching between noncontiguous banks — requires a little more effort. However, holding down a bank button puts you in Fast Scroll mode, which speeds up the process.

The Utility button allows users to adjust the noise gate, give names to programs, and set up pedal parameters for one of the optional foot controllers (see the sidebar “A Choice of Pedals”). The Global button accesses MIDI channel and dump functions as well as the S/PDIF level.

I wish that Vox had included a function to let you do an A/B comparison of the current edited parameter value with its original value from the saved or factory preset. The display does have an indicator light to let you know that you've returned a knob to its original state, but by going back you lose your edited setting. It would be nice to have a button that easily compared the two. (As a work-around, you can save your edited preset to a new location and compare by toggling between the presets.)

The LED display is relatively spartan. An eight-character top line shows program and parameter names. The lower line tells you the Valve Type of the original amplifier being emulated, whether the current parameter value is the original or an edited value, and what the current parameter value is.

If you prefer computer-style editing, the Vox Amps Web site (www.voxamps.co.uk) offers a useful ToneLab editor-librarian application free for the PC. Unfortunately, there is no Mac version.


Explaining the technology of the ToneLab's Valve Reactor section requires a bit of background regarding the interaction between a guitar and an amplifier. A preamp alone does not generate the tone of a guitar amp. The ways the tubes of the power amp interact with each other and with the playing style of the guitarist — aka the “feel and touch dynamics” — are integral components of the final sound.

As any tube-amp aficionado will attest, the feel and touch dynamics of a tube amplifier depend on the number of tubes, on whether the amp is a Class A (meaning the tubes receive a constant current) or Class AB (meaning the tubes receive current in a “push-pull” grid), on the size of the output transformer, and so forth.

While other modelers on the market attempt to approximate this interaction digitally, Vox has gone the opposite direction, using a 12AX7 (sometimes referred to by its British name, ECC83) tube as a functional 1W power amp. And because the 12AX7 is a “dual-triode” tube (meaning it can function as two tubes in one), the ToneLab uses it as both a 1W Class-A and a 1W Class-AB power amplifier. After the power amp, ToneLab features what Vox calls a Virtual Output Transformer. So not only does the Valve Reactor model the sonic characteristics of the tube amps it emulates, it delivers actual interaction between the tube power section and the output transformer as well.


One significant effect of the Valve Reactor technology is that the gain staging on the ToneLab is far more complex than on other modelers. In addition to the master Output Level knob on the rear of the unit, the ToneLab has three parameters that affect the final output level and sound: Gain, VR Gain, and CH Volume. The parameters' functions change depending on the model selected. In the emulations of vintage amp models that didn't offer a master volume, the Gain knob functions as a volume control, and the VR Gain serves as the volume into the Valve Reactor power-amp circuit.

For models of amplifiers that did offer a master volume knob, the Gain knob affects preamp gain, and the VR Gain affects the power-amp gain. The CH Volume knob acts as the attenuated output — in other words, the output that your speaker or line input sees. Although this control scheme might seem confusing at first, it makes perfect sense when you start using the ToneLab, and it adds to the realism of the models.


To test Vox's claim of authenticity, I compared the ToneLab with a vintage Fender Blackface Twin, a 1968 Marshall JCM Plexi, a modern Marshall DSL50, a '90s Mesa/Boogie Dual Rectifier, and a modern reissue Vox AC30 — all amps that the ToneLab emulates. For these tests, the ToneLab was patched into my recording rig and played back through my Dynaudio BM6A active studio monitors.

I didn't expect the ToneLab to be sonically identical to the tube amps — even two Plexis won't sound exactly the same — but I wanted to see if it captured the texture, feel, and interaction of the originals. The well-written and comprehensive manual was a huge help in making a fair comparison possible. It lists not only which amps were emulated by the ToneLab's models, but also which specific inputs and channels were simulated. This information allowed me to duplicate the channel and input assignments when comparing the real amps to the ToneLab.

ToneLab's Blackface 2×12 captured the tone and feel of the Fender Twin (see Web Clip 1), although it sounded a bit thinner. The ToneLab's Plexi model — Vox calls it UK68P — was also quite good (see Web Clip 2). The feel was dead on, and the tone captured the most recognizably “Marshall” characteristics. The Marshall DSL and Vox AC30 (see Web Clip 3) were emulated nearly perfectly — I was hard pressed to tell the difference, even when staring at the unit being tested. I can't imagine trying to tell the difference in a blind test! ToneLab's Recto emulation accurately captured the feel and distortion characteristics of a Mesa/Boogie Dual Rectifier (see Web Clip 4), although I didn't feel the ToneLab reacted to different preamp settings the same way the Mesa did.

Most importantly, the ToneLab was more reactive than any other modeler I've tried. It felt quite touch sensitive, and the accuracy of the amp models didn't change as I rolled off the volume or switched guitars and pickups. I was impressed.


I'm always a bit suspicious of cabinet emulations. Considering that even with the same speaker configurations (including speakers of the same model), cabinets from different manufacturers sound completely different, how accurate can any simulation really be? Vox was smart enough to specify in the manual the precise brand of cabinet as well as speakers used in their various emulations.

I compared the ToneLab against two actual cabinets: a custom Black 2×12 with Celestion G12H30s and a Marshall UKV30 4×12. (For these tests, I first listened to the ToneLab — with its cabinet simulation on — plugged in through my studio monitoring system. I then compared that with the sound of the ToneLab — with the cab simulation turned off — plugged directly into the real guitar cabinets.) The ToneLab's simulations were better than what I've heard on other modelers, but still a bit thinner-sounding than the real cabinets. However, choosing a matching amp and cabinet simulation (such as the Vox cabinets with Vox amps or the Black cabinet with the Blackface simulation) made the simulation even more effective.

On the other hand, turning off the speaker simulator and running the ToneLab through a power amp (I used the power section of a Rivera Knucklehead II) and a cabinet gave me an excellent sound. Even if it didn't precisely match the specific modeled amp, it did sound like a tube amp through a power amp, not like an amplified processor.


Like the amps and speakers, the ToneLab's effects are not simply digital multi-effects, but emulations of classic guitar pedals and effects. There are four effects sections: Pedal, Modulation, Delay, and Reverb. You have no control over the order of these effects, and they all come before the amp and speaker simulations. You can, however, use any combination of the four sections simultaneously. The ToneLab also allows you to bypass any or all of the effect sections.

I didn't have access to all the original stompboxes for an A/B test, but I would definitely say that the Vox Wah and U-Vibe (Univibe) effects sounded quite good. I wasn't that impressed with the sound of the Fuzz effect, and the rest of the compressors and boosts in the Pedal section ranged from decent to good.

The Chorus, another standout effect, sounds very rich. The other Modulation effects (Phaser, Flanger, Tremolo, and Rotary) and the Delay sound good in the context of the various amp models — they sound more like guitar effects than digital effects. That's a good thing for a guitar modeler.

The Delay is useful, especially considering that you can control it with the Tap Tempo button on the face of the unit. The Reverb section — which includes Spring, Room, and Plate emulations — was my least favorite of the effects groups. To my (admittedly picky) ears, the Reverb models lacked the density of others I've heard.


The Vox ToneLab is solidly built and easy to use. What it lacks in bells and whistles it makes up for in quality. If your budget is limited and you're looking to squeeze in as many features and sounds as possible for the lowest price, you might be happier with a different unit. But if authentic amplike tone and feel are what you're after, the ToneLab is sure to satisfy.

Orren Mertonis the author of Logic 6 Power (Muska & Lipman, 2003), and can usually be found playing guitar through one of his many of vintage and modern amps.


The ToneLab offers excellent expression-pedal functionality. Pedals can be used to continuously control wah-wah, volume, modulation speed, flanger frequency, and delay or reverb level within user-specified boundaries. If you're using one of Vox's two optional foot controllers, you can also select programs, turn individual effects on or off, activate the tuner, and control delay time using a tap tempo button.

The less expensive of the two controllers is the VC-4 ($200). It lets you choose between 16 program presets and to turn individual effects on or off, and it offers a dedicated tap-tempo button and expression pedal.

The VC-12 has even more features ($350; see Fig. A). This solid-steel pedal has the same functions as the VC-4, and it gives you control over 48 presets, a tuner, and a second expression pedal.

ToneLab Specifications Inputs(1) ¼" unbalancedOutputs(2) ¼" balanced/unbalanced; (1) ¼" TRS headphone; (1) RCA S/PDIF (44.1 kHz)Maximum Input Level+5 dBVAdditional I/OMIDI In, Out/Thru; Vox bus (footpedal)Presets48Amp Models16Effect Models21Mic/Cabinet Models16A/D/A Converters20-bitSampling Frequency44.1 kHzPower Supply9 VAC; 3.0A line-lump power supplyDimensions12.56#34; (W) × 3.11#34; (L) 5 8.39#34; (D)Weight5.5 lb.



guitar-amp modeling processor


PROS: Realistic-sounding guitar-amp models. Good cabinet models. Solid construction. Tube-amp-like reactivity to guitarist's performance. Easy-to-use editing interface.

CONS: No compare function. No word clock for digital output. Fewer models and connectivity options than some competing units. Editor-librarian software PC only. Rear-panel jacks not bolted to chassis.


Vox Amplification
tel. (516) 333-9100
Web www.voxamps.com