Engl Amps Invader 150 Head review

Engl's latest features a six-pack of EL34s for a knock-out punch

  • £1899
  • $3562.49
Awesome power and sounds are here in abundance

MusicRadar Verdict

You great tone no matter what preset you use, but that power is overkill for all but professionals.


  • +

    The range of sounds and control. Superb MIDI implementation. Seamless switching. Very low noise levels. Great manual.


  • -

    No low power option. Just for pro's, really.

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Boasting no less than six EL34 output valves, the InVader 150 is guaranteed to raise more than the odd eyebrow and, used to excess, it will probably do a good job of testing buildings for structural integrity too. Designer Horst Langer is known for getting the most out of his amps in terms of tone and features, so how does the InVader 150 stack up against the rest of Engl´s range? Let´s take a closer look.

Engl´s house style is a mix of vintage and hi-tech modern, into which the InVader fits nicely. A large, neatly finished plywood sleeve surrounds the tough steel chassis, with a front grille consisting of horizontal black chrome tubes through which you can see the valves, illuminated by a row of blue LEDs when the power is switched on. As well as those six big output bottles, the InVader 150 also sports two massive transformers leaving no doubt that this isn´t an amp for those with weak hearts. Internally, the electronics are entirely mounted on PCBs and the layout and component quality is typical of Langer´s exceptionally high standard, including a clever protection circuit that prevents damage if a speaker lead isn´t plugged in - it also shuts the power amp off in the event of a valve failure and can even tell you which valve is defective. There´s also a handy ground lift switch on the rear panel, which can be used to remove the hum caused by ground loops, although it should be used as a last resort.

The InVader 150 is a four-channel amp, but with a slightly different approach as all channels can be used for rhythm and lead work, the difference between them being more to do with tone and dynamics than gain.

The front panel is busy yet neatly laid out and easy to follow, although as with most Engls, it helps to have the instruction manual to hand. Each of the four channels gets the usual gain, volume and three-band EQ - over to the right there are global controls for presence and Engl´s depth punch function, which respectively fine-tune the power amp´s high and low frequency response, along with two switchable master volumes. Near the single input jack, a pair of small pushbutton switches operate a global gain boost function and bright tone shaping for channels 1 and 2, with four more for channel selection, while another quartet of buttons adjacent to the standby switch select the InVader´s dual master volumes, noise gate, effects loops and memory functions. All these switching options are programmable and easily stored for each channel.

On the rear panel you´ll find a pair of MIDI in and thru sockets, along with two more jacks for use with alternative footswitches like Engl´s Z-9 controller. The noise gate´s threshold

level control is here, along with two parallel effects loops that have separate mix level controls. There´s plenty of output scope too, with separate preamp and line sockets as well as five speaker jacks that can handle almost any combination of cabinet. MIDI is an Engl speciality that you can use to access all the InVader´s switching functions, storing up to 128 presets. Without getting too bogged down in the technical details, this means you can effectively treat the InVader as an eight-channel amplifier as each channel can be selected with or without the gain boost engaged, as well as having the amp send or receive program change commands from other MIDI devices, like a sequencer or an effects unit. If you´re beginning to hyperventilate at this point, try to relax and stop searching for a paper bag as, despite the InVader´s complexity, its control layout and switching is logically arranged and getting to grips with it is much easier than you´d expect. This is helped by a very well-written and informative instruction manual. If you don´t want to use MIDI at all, there is provision for alternative footswitching, using either Engl´s own stageboard or a standard latching two button controller that will simply let you access the four

channel presets, which you can set up and store to taste.


Engl is up with the world´s best for manufacturing quality and the same thing goes for its tone. Like the incredible SE, the InVader is capable of delivering an extraordinarily wide range of sounds, all of them highly usable.

As we mentioned above, each of the InVader´s four channels can be used for rhythm or lead work, although channels 1 and 2 are the most rewarding for cleaner sounds while 3 and 4 deliver the goods when cranked up with lots of distortion. Channel 1 is brighter and appears to have a little more headroom, while channel 2 is more dynamic in terms of its response and ideally suited for medium gain blues/rock playing, setting up the amp to distort when you hit the strings hard. Channels 3 and 4 seem to work better in high gain mode; the former is biased towards the scooped out mid-range sound that´s still very fashionable, while the latter benefits from increased mid-range punch, though it demands a more precise picking technique. All four channels have an American bias, but the Engl is full of character and has its own personality.

The InVader´s built-in noise gate was easy to set up and proved especially useful in keeping background hiss out of the way, although it should be mentioned the Engl is electrically very well-behaved, with signal to noise ratios that are better than many amps in this class. There´s a barely audible ‘pop´ as the gate triggers, but it isn´t really necessary to use it at low volume levels, so this isn´t a problem. However, using this amp as it should really be heard will be a problem for some players as the InVader is a monumentally loud amplifier, so loud in fact that our test 4 x 12 loaded with 240 watts of loudspeakers was beginning to sound stressed as the InVader´s volume controls were wound up beyond threat level. There is no low power or pentode/triode switching available that can be used to tame the Engl´s output stage, so be warned - this is an amp that takes no prisoners. While it sounds good at typical small to medium-sized rock gig volume levels it´s really intended for stadiums and very large concert halls, where a pair of cabinets will really help you to get your point over to the masses with power to spare.

Engl has mastered the difficult art of building multi-function amps that deliver great tone no matter what preset you use, and the InVader is no exception. It´s an excellent design that´s easy to get to grips with, versatile and great fun to use. Compared to the competition it´s reasonably well priced too, bearing in mind this is a high-end amp aimed primarily at pros. So despite the superb sounds, appeal will be limited.

Music Radar Team

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