Packing more features than many of its competitors, the HeadRush Flex Prime covers a lot of ground. With a huge selection of amp and effects models, the ability to create your own captures as well as a built-in looper and Wi-Fi, it’s one of the most feature-rich multi-effects pedals I’ve ever tested.
Pros
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Huge array of amps and effects.
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Create your own captures.
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Built-in looper for practice and performance.
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Compact size and rugged build.
Cons
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Very sensitive footswitches.
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Touchscreen can be a bit fiddly.
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Although HeadRush probably isn’t the first name that comes to mind when you're thinking about buying a modern multi-effects pedal, maybe it's time to change your perceptions a little. Quietly building a great reputation for themselves in the sphere, the HeadRush Flex Prime is aiming to show the company can more than compete with the big boys in Boss, Line 6, and Neural DSP.
A seemingly natural competitor to the Boss GX-10 and Line 6’s POD Go, Flex Prime offers plenty of modeled amp and effects tones in a compact chassis. Boasting a touch screen, a looper, gapless preset switching, built-in Wi-Fi, and a cloning (read: capture) system that allows you to capture the sounds of your favorite amps, effects, and even VST plugins.
It’s a heady cocktail of functionality, and on the face of it, it looks as though HeadRush has made a wishlist of all the best features available in multi-effect pedals and crammed them all into one unit. Is it going to be more jack of all trades, master of none though? Time to find out...
Connectivity: Inputs: 1x 1/4" (instrument), 1 x 1/8" (aux in), Outputs: 2 x 1/4" (L/Mono, R), MIDI: 2 x 1/8" TRS Type A (In, Out), USB: 1 x Type B, Headphones: 1 x 1/8", Other: 1 x 1/4" TRS (expression), 2 x 1/4" TRS (FX send, FX return)
Bypass: N/A
Power: 12V DC 3A center-positive power supply (included)
Coming in more compact than both the POD Go and the Boss GX-10, the Flex Prime feels relatively lightweight, yet durable and rugged in your hands. The front of the unit is a thin sheet of metal with hard plastic back and sides and overall it feels well put together. Although I wasn’t willing to test it for real, you’d hope the touchscreen is made of something very rugged as it dominates the front of the unit. A wayward stomp during a gig could potentially cause some serious damage.
(Image credit: Future)
The two knobs to the left of the touchscreen feel nice and sturdy, replicating something of the look of those on a Marshall. I like that the volume knob goes to 11 too. The 360-degree encoder moves in notches for fine-tuning, and you push it down to confirm a selection. Meanwhile, the three footswitches are nice and tall, with a smooth feel minus any loud clicking when you press them in.
The expression pedal on my review model was very stiff, too stiff in fact for fine control when using a wah effect but it is adjustable using a hex wrench. It’s got a skateboard-style grip on the top of it as well which means no slipping at all, even when you’re using it in your socks or barefoot.
The size could be a factor for some though, especially if you’re used to a full-size expression or wah pedal. You just don’t get that same control that you would and for my UK size 9 foot, it was just a little bit too small for my taste. I was never able to get both my heel and the ball of my foot on the pedal at the same time, which made it difficult to get my usual level of control over the wah, volume, and whammy effects.
Usability
(Image credit: Future)
Usability rating: ★★★★½
My first test of any multi-effects pedal is how easy it is to use without any prior knowledge, so I always dive into any tests in this particular category without having read the manual. The Flex Prime is definitely one of those you can just get straight to using thanks to the very clear display, and overall it felt intuitive for pretty much everything apart from deeper editing options.
Changing banks requires a press of two footswitches at the same time but with the way they’re positioned it's easy enough to do this even barefoot. If you’ve got tiny feet you might have to start twisting your ankles to do this though. The footswitches aren’t the usual latching type you might expect to see on a guitar pedal, however, which means slight presses when hovering your foot over or a brushed cable can accidentally trigger them. Something you'll need to look out for if you want to take it out on the road.
I was immediately impressed by the seamless switching. There’s no discernible drop in sounds that you get with a lot of units, even the hallowed Quad Cortex, which means you can use multiple rigs for the same song and not have to worry about a slight gap when switching. It also massively opens up the possibilities for your sounds, meaning it is entirely feasible to use a Fender clean tone for your verse arpeggios, a cranked Marshall for your chorus rhythm, and an Engl Powerball model for your solo.
(Image credit: Future)
The display is nice and bright even in full daylight and when playing standing up I could just about read the preset text with my glasses on. Each preset has two modes, usually a rhythm and a lead, whilst the third footswitch toggles an extra effect on or off. If you hold the first footswitch down it gives you the option to switch between stomp and rig modes which makes for slightly easier preset switching, although I was happy to keep using the two-footswitch option for this.
Jumping into the editing modes can be done via a hands-free mode accessed by holding in the first footswitch, so you could make your changes just using the footswitches but for me, this was way too convoluted. Instead, when using the touchscreen you can simply double-tap on any of the effects or amps in your chain to jump into a zoomed-in mode that allows for tweaking. If you press and hold on a parameter you can then slide your finger to increase or decrease, which works really well, even if you’re only doing incremental changes.
If you’re not a fan of touchscreens or you don’t want to cover yours in fingerprints, you can also use the encoder knob to select your parameter, push it in to select, and then tweak your settings that way. It does give you a slightly finer control this way, with each notch in the encoder moving the parameter by 1%. Exiting took me a while to work out as it’s a tiny icon on the top left of the screen that isn’t immediately obvious.
Changing up your signal chain can be done by dragging and dropping the blocks, or tapping on an empty block to add something new. It makes it super easy to experiment with sounds, like moving a chorus block from in front of the amp to in between your amp and your cab. The movement of the blocks feels smooth and easy to use, and no different from using a smartphone. I didn’t suffer any lag or jumping around during my tests, although my screen did get absolutely filthy in the process.
(Image credit: Future)
Using the looper is again pretty self-explanatory if you’ve used one before, and I really like the loop display which shows you how long you’ve got left until it loops back around again. It’s accessed via a long press of footswitch number two and works similarly to most two-button loopers. There are a lot of deep options too like the ability to move your looper in the signal chain, doubling or having the speed of your loops, reversing playback, adding a metronome, sync tempo, and a myriad of other choices.
The Flex Prime also includes both its own amp cloner software and a copy of ReValver. This means you can capture the sound of your amp and cab, amp alone, or your favorite drive pedals. The process itself is surprisingly simple and took me just a couple of minutes to capture the tone of my Orange Rocker 32 with an SM57 pointed at it. In fact, I spent longer setting up the amp and mic than the actual process of capturing.
I spent longer setting up the amp and mic than the actual process of capturing
With some EQ tweaking of the final product, I was able to get the tone pretty close to my actual amp. Not exact, but close enough that I was happy with it. HeadRush also allows you to create what they call a ‘super clone’. Clones (or captures as they are more commonly known) are just a snapshot of the amp with particular settings, so tweaking these settings doesn’t result in the same response you’d get from your actual amp. With a super clone, you can capture your amp at a variety of different gain levels for example, then blend them into one to allow you to change the gain realistically via the hardware unit.
It’s a cool option to have if you’re that committed to getting a realistic capture of your tube amp, and also opens up some creative options where you could potentially combine different amp tones and sweep through them using the hardware unit. Having tested the Quad Cortex Nano capture process as well, I can say they’re both as simple as each other, and both deliver superb results in relatively little time.
Sounds
My testing rig for the HeadRush Flex Prime consisted of a Fender Tele, Gretsch semi-hollow, and Chapman baritone through the Positive Grid Spark Live's FRFR speaker in stereo (Image credit: Future/Matt McCracken)
Sounds rating: ★★★★☆
It’s all good having a million and one options for tweaking, but at the end of the day what’s most important is how it sounds. I use the Positive Grid Spark Live to test my modeled amps at volume with its dual FRFR speakers, and I've had a Quad Cortex, HX Stomp, and Boss GX-10 through the same rig to compare it to.
In a vacuum, the HeadRush Flex Prime sounds are really good. The amps offer a very realistic feel to them whether you’re using a clean tone, mid-gain, or high-gain chugging. It was easy enough to lose myself in the idea that I was just playing in front of an amp rather than a pedal through a speaker.
(Image credit: Future)
There was no fizziness that I could detect at higher gain settings and all of the base-level patches have an excellent quality feel to them, although you’ll probably want to tweak some stuff to suit your personal playing style. Amps are very personal but having played essentially all the multi-effects platforms out there right now, HeadRush competes with the big boys here.
The sheer choice is fantastic, and the combination of HeadRush models, ReValver clones, and the ability to create or download 3rd party clones means you won’t be short of amp models to pick from. It’s the same with effects too, and there are some really out-there options like the time-warp pedal, plus loads of synth patches that can turn your guitar into a completely different instrument.
Comparing it to others in the same price bracket, it definitely holds its own
While the amp models are great on their own, when comparing them to other units I've reviewed I found they didn't quite give me the same grin-inducing feel that more high-end modelers have. Comparing it to others in the same price bracket, it definitely holds its own, but if you're looking for the utmost realism in your amp tones, you might find that some of the models in the Flex Prime don't quite nail the dynamic response of their real-life counterparts without significant editing or the addition of 3rd party IRs.
I recently tested the Boss GX-10 for Guitar World, which is a great unit for direct comparison. While I preferred the amp models on the Flex Prime, I found the effects were superior on the Boss GX-10. To my ear, they sounded more high-definition, delivering plenty of 'wow' moments when I tested it. The effects on the Flex Prime are by no means lackluster, but they didn't make me jump out of my seat either.
Verdict
(Image credit: Future)
For me, the HeadRush Flex Prime absolutely competes for attention in the crowded multi-effects pedal market. It’s managed to collect all the best features of each of its competitors and place them into one pedal, giving you captures, amp modeling, a looper, plenty of DSP power, signal flexibility, plenty of connectivity, and an expression pedal into an easy-to-use, compact, and durable feeling unit.
There are some small issues for me, like the sensitivity of the footswitches which is too much, and the touchscreen and menu navigation can be a bit fiddly too. I can see the touchscreen-heavy functionality putting certain users off and without many hardware buttons, you’re left with the rather convoluted hands-free mode with just three footswitches to change your parameters.
Final verdict: The amp and effects models aren’t the best I’ve ever heard, but it’s a solid competitor for both the Boss GX-10 and the Line 6 POD Go in terms of both sounds and particularly functionality. It's also fantastic value for money for what you get, and gives you more features than the comparable Boss and Line 6 units, albeit for slightly more money.
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Ratings scorecard
Test
Results
Score
Build quality
Rugged with quality feel
★★★★★
Usability
User-friendly with plenty of depth
★★★★½
Sounds
Superb variety of amps and effects
★★★★☆
Overall
A solid multi-effects with some small flaws
★★★★½
Also try
Line 6 POD Go - $499/£349
Another feature-packed amp and effects modeler it’s slightly cheaper than the HeadRush Flex Prime and for my money, sounds slightly better. It doesn’t have quite as many features as the Flex Prime, however, which could put it further back if you’re after the most functionality for your money.
Well-built and easy to use, the Boss GX-10 is a superb option if you want the very best effects modeling. For us, however, the amp modeling side is starting to feel a little dated and the Flex Prime does a better job of simulating guitar amps. It is cheaper than both the Pod Go and Flex Prime, which does give it an advantage.
More of a straight amp capture system rather than a true multi-effects, the Neural DSP Nano Cortex is nonetheless worthy of your consideration just for the sheer quality of its amp captures. Better suited to those with an existing pedalboard, it’s a pricier option but the Neural amp models are amongst the best out there right now.
Matt is a Junior Deals Writer here at Guitar World. He regularly tests and reviews music gear with a focus on guitars, amps, pedals, modelers, and pretty much anything else guitar-related. Matt worked in music retail for 5 years at Dawsons Music and Northwest Guitars and has written for various music sites including MusicRadar, Guitar Player, Guitar.com, Ultimate Guitar, and Thomann’s t.blog. A regularly gigging guitarist with over 20 years of experience playing live and writing and recording in bands, he's performed everything from jazz to djent, gigging all over the country in more dingy venues than you can shake a drop-tuned guitar at.
