Vox has updated its popular tube-equipped digital modeling Valvetronix amp line with the addition of the Valvetronix +-series. The latest incarnation features 33 amp models (upgraded from the original’s 22), 25 built-in effects (up from the original’s 12) of which four can be used simultaneously, the ability to create and store footswitchable user programs (two banks with four channels), a built-in tuner, a power attenuator, and Vox’s 12AX7 tube-driven Valve Reactor circuit. The +-series models include the VT20+ (30W max, with one 8-inch speaker), VT40+ (60W max, with one 10-inch speaker), VT80+ (120W max, with one 12-inch speaker), and the VT120+ (150W max, with two 12-inch speakers). For this review, I tested the VT20+ ($280 MSRP; $169.99 street).

The View From Above
The top panel consists of two well-packed rows of knobs and buttons (see Fig. 1). Starting from the top left, the first button is Preset, which lets you toggle between three preset categories: Basic presets are amp models without effects (except for an occasional reverb); Effect presets add processing to the amp models; and Song presets are amp and effects combinations that are modeled on the tones from popular songs.

The next knob, Amps, lets you select from 11 amp models, each with three variations. The models are indicated by abbreviations like Cali Clean, US 2X12, Vox AC30, and BTQ Metal, among others. Some are obvious and for some you’ll need to refer to the descriptions in the manual. For instance, without the manual, I’d never guess that selecting the BTQ Metal amp in Standard mode would call up a model based on the Dumble Overdrive Special. The variations are selectable by an adjacent button and the chosen variation is indicated by the same LED color scheme as the Presets. In this case, Green is for Standard (STD), Orange for Special (SPL), and Red for Custom (CST).

Conventional amp controls follow—Gain, Volume, Treble, Middle, Bass, and Master. Next to the Master knob is a Power Level knob that lets you attenuate the output from 30W to 0W. Last on the top row are an aux input, for practicing along with line-level sources, and a headphone jack.

Fig. 1: Vox packed a lot of features into the VT20+.

The bottom row starts with the input jack followed by the User Programs section, which contain the Channel Select and Tuner functions. There are six buttons—Bank (for selecting the channel bank), CH1, CH2, CH3, CH4, and Tuner/Bypass, which turns off all of the effects and engages the tuner. On top of each button in the User Program section are LEDs that serve a dual function. In Channel Select mode they indicate the chosen bank by lighting up either green or red. In Tuner mode, they indicate the string sounded and its tuning status.

The Pedal section is up next with two knobs. The first knob selects from the effect types, indicated by labels like U-Vibe, BRN Octave, Treble Boost, Tube OD, and Gold Drive, among others. The next knob, Value, adjusts a pre-selected parameter, which differs depending on the effect. For example, it governs the speed of the U-Vibe effect and the gain for Gold Drive, which is based on the legendary Klon Centaur pedal. The Value knob serves a dual function; if the Bypass button is activated, the knob is used to adjust the noise reduction sensitivity.

The pedal effects are followed by the Mod/Delay section, which consists of two knobs and a button. The first knob chooses the effect—CE Chorus, G4 Rotary, Pitch Shift, Filtron, and Tape Echo, among others. The next knob, Depth, controls the parameter of the chosen effect—depth for the choruses, sensitivity for the Filtron, etc.. A Tap button rounds out the Mod/Delay section, and serves a dual purpose; first as a tap tempo (a blinking LED on top of the button visually indicates the tempo) and second to allow access to further control of the parameters. If you press Tap twice you can then use the Depth knob to adjust other parameters, such as speed, pitch, or delay time depending on the effect chosen. If you hold down the Tap button you can adjust other parameters, such as feedback and resonance, using the Depth control.

Reverb, the last knob on the bottom row, offers room, spring, and hall settings. The knob also controls the wet/dry mix of the effect.

The rear panel has the AC connector, a power switch, and a jack for connecting the optional footswitch (Vox VFS5, $59).

Modes of Operation
Because there are so many features crammed in, the VT20+ has a bit of a learning curve. It’s not always intuitive to use, and you will need the manual to identify many of the amps and control functions.

There are three modes of operation—Preset, Manual, and Channel Select. Preset mode houses the 99 factory presets (Basic, Effect, and Song). In Basic and Effect, all of the settings are pre-programmed to a fixed position regardless of the physical positioning of the knobs. The Amp, Pedal, or Mod/Delay selector knob positions do not necessarily indicate the models or effects that you’ll hear when you call up a preset—this is typical with modeling amps, and it’s something new users need to remember. Unfortunately there is no list of any of the Basic or Effect preset settings so it’s almost like shooting in the dark until you find a sound you like.

The presets are editable, so you can tweak any factory setting to your liking then save it. The Song presets are renditions of tones inspired by famous guitar-driven songs, and all of the songs are listed in the manual.

In Manual mode, the amp works like a conventional amp. This is the only mode where the physical locations of the knobs indicate exactly what’s coming out. Channel Select mode lets you access the user created programs via the Bank and Channel switch.

Bands In A Box
Overall, the VT20+ sounds pretty good. I started with the Song presets and played through settings based on Green Day’s “Know Your Enemy,” The Police’s “Message in a Bottle,” Stevie Ray Vaughn’s “Pride and Joy,” and Van Halen’s “Hot for Teacher,” among others. They all did a credible job of mimicking those tones and, with a little EQ adjusting, I was able to dial things in closer for my specific equipment (a Peavey Wolfgang guitar for “Hot For Teacher,” a Fender Stratocaster for “Pride and Joy,” etc.).

I also came up with some neat sounds in Manual Mode. The clean sounds I got were nice and I enjoyed the different amp model variations, although I did note a slight thinness to the overall sound.

The distortion effects are strong, particularly the high-gain settings. Without much effort, I was able to get many useable sounds. The effects are generally comparable to good pedals and would do the job for most live applications.

The built-in power attenuator is one of the best features of this amp. It proved to be really useful when I recorded a demo track in my apartment. I was able to get a great pushed-amp sound at a neighbor-friendly volume.

Top 20
With pretty much every conventional sound and feature at your disposal, the VT20+ is a great grab ‘n’ go amp. But it’s best suited for someone who will dedicate the time it takes to get to know the variety of features this amp offers, rather than someone who is looking for something simple to play through.

Of course, if you just need a few basic sounds, it won’t take long to set them up. There are certainly plenty to be had in this amp.

Pros: Feature packed. Nice sounding effects. Power attenuator.

Cons: Some features are difficult to access without reading the manual. No list of Basic and Effect preset settings.

NYC-based guitarist Joe Charupakorn writes for Guitar Edge magazine and is a best-selling author and editor for Hal Leonard Corporation. Visit him on the web at joecharupakorn.com.