VOX Valvetronix VT20+ Guitar Amp Combo Review

Review of the VOX Valvetronix VT20+ guitar amp combo

During one of my Fender Champ’s visits to the service shop I found myself without a quality guitar amp for recording. By good fortune, and some gentle hints to my better half, a brand new VOX Valvetronix VT20+ arrived one festive morning.


The VT20+ is a compact combo of similar size and weight to the Champ but offers a much higher 30W output feeding a VOX 8” speaker. For recording work this turns out to be more than ample.


I got my Les Paul Standard plugged in real quick and, well, I kind of stopped. I was used to just volume, bass and treble controls; this was quite a different proposition. Like the rest of the world I never read instruction manuals, but in this case I made an exception. With thirteen rotary controls and nine pushbuttons this is not a plug, play and party machine.


Luckily the excellent manual has a Quick Start section which gets you playing pretty quickly. What I hadn’t realised was just what a ‘tardis’ of sounds this little amp could produce. No less than thirty-three different amps are modelled, and very importantly, for me anyway, all feeding a 12AX7 (just like my Champ) valve output stage.


The way that VOX have designed the signal chain, is very clever, as you do all of the digital modelling and the important valve amplification before the final power (read ‘loudness’) level control. In practice, this means you have relatively little variation in tone no matter how much you wind up (or down) the final power level. This is a god send for those recording in the home especially in terms of neighbourly relationships.


The rest of the signal chain is a pretty good way to review the amps facilities, so starting from left to right;


‘Peddle Effects’ are digitally modelled creations of 11 popular foot pedals COMP, ACOUSTIC, AUTO WAH, U-VIBE, BRN OCTAVE, TREBLE BOOST, TUBE OD, GOLD DRIVE, ORG DIST, METAL DIST and FUZZ. In most cases the effects are in the same league as their stand-a-lone units.


Next in line comes the pre-amp modelling section. I need to say something right now about the 33 pre amps available. They offer a wonderful range of tones and it’s hard to believe at times that they’re all coming out of a combo which is no bigger than my little Fender Champ. Each of the amps is well described in the user manual and pretty soon, you find some favourites, as we shall see later. The 33 amps are split into 3 banks of 11 with each of the 11 major types (e.g. VOX AC15) having three variants.


The output of the pre-amp feeds the second effects section which covers mod/delay and reverb. Again 11 effects are offered, CE CHORUS, MULTI CHORUS, FLANGER, ORG PHASE, TWIN TREM, G4 ROTARY, PITCH SHIFT, FILTRON, TAPE ECHO, DELAY and CHORUS+DELAY. And finally into the Reverb section which offers ROOM, SPRING and HALL.


In addition to manually controlling the two effects sections, the amp offers a massive 99 pre-sets (BASIC, EFFECT and SONG for each amp type), so you can wander through the pre-sets till you find something appropriate.

More useful, are the eight user memories, so you can find your favourite combinations of amp and effects and recall via the amp control panel or an optional foot pedal.


Even after extended use, I still find having GAIN, VOLUME, MASTER and POWER level controls a bit confusing (being used to only one) and it’s important to remember that whilst the gain and volume controls form part of a preset (including those you set up yourself), the master and power controls are not memorised.


There’s a single ¼” guitar jack socket plus additional (rather flimsy) mini jack sockets for stereo aux input and headphone output.

The amp makes very clever use of noise reduction circuitry, so that when using any of the 33 presets, background noise is never a problem. However I found this can get complicated when you start from a preset, and then say increase the gain, and suddenly the noise reduction sensitively is no longer matching to the gain structure. When operating in manual mode (just like a conventional amp) then you have to adjust the noise reduction sensitively to match to the settings of the gain and level controls otherwise background noise can get quite intrusive.

The available amps sounds progress in a reasonably logical manner from clean (fully anti-clockwise) through US bluesy, to rock and into serious metal territory. 


My favourites are;

US Blues which is great in both standard a custom variants. Standard allows you to range from a quite smooth bluesy sound with just a little bit of overdrive depending on high hard you play, whereas the custom variant gets into more serious overdrive territory but without losing that beautiful smoothness of the basic amp.


The VOX AC30 is (not surprisingly) well modelled and again it has the capability to react very nicely to how hard you are playing.

I’m not so into the metal amp sounds, but then to be fair, I’m not that into metal!

The speaker handles all of the tone variations well, even up to quite loud levels, and with the lack of necessity to use high levels to obtain the desire tone, the speaker should live happily into old age.


Each of the 11 pedal effects have their uses and each has a single knob adjustment mostly typically to adjust the gain into the effect. My favourites are the Auto Wah (very funky!) and the Gold Drive which is a really nice overdrive with a great sounding tone so I use this quite a bit.

The 11 mod/delay effects are all fine, The Flanger is really cool and you can get some nice ‘spaceship landing’ effects. My favourite is the G4 Rotary and just for a moment you can imagine a real Leslie cabinet. The only problem is you need two spare hands to be able to adjust the speed so it’s hard to play the guitar and play with the effect at the same time! But it is fun.


The single reverb effects knob does a decent job of the three ROOM, SPRING and HALL effects on offer, and the tonal quality holds up very well.

So what am I not so keen on?


There are no on/off switches for the two effects sections, so you have to remember to turn the Value and Depth knobs fully anti-clockwise. It’s quite easy to leave them a few degrees from that (action is quite light) and you can’t understand where that strange effect is coming from. It also took me quite a while to realise that even the amp presets labelled ‘basic’ (which I thought meant ‘no effects’) actually have effects programmed in. To be fair that’s why they have a manual mode!


If you are starting from a preset, then there is a system for indicating when a rotary control is passing through it’s stored position (an LED goes out) but you have to have your wits about you. I prefer to use the amp in manual mode and build up sounds to be stored in the eight user memories. It’s a real shame it is only eight, as you want to store more and there’s no way to overwrite the 33 presets which come with the amp.


The VT20+ is a lot of fun to use and a seriously good recording amp especially taking into account its very modest price. The range of tones available is almost never ending and you can pick your eight favourites and have then stored away for instant recall. On the whole, the ability to conjure up tones, completely independently from the output power level, is a huge asset. Occasionally I looked for a little more dynamic sensitivity to playing style but this is a minor comment compared to the benefits that this little amp brings to your recording set up. You could take it gigging of course but be prepared to mic it up in most circumstances. Higher power versions are available if that’s going to be a requirement.

Best features : Great ranges of amp sounds available even at low power levels.


Weakest points : With only eight user memories but such a flexible feature set, you can spend a lot of time checking and rechecking combinations of buttons and knobs.


Rating : 8/10

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