Other Amps

Positive Grid Spark review


I took delivery of my Positive Grid Spark amp today and I thought I’d do a little review. I don’t really have a great deal of experience with many types of amps or effects so my review will concentrate more on how it sounds rather than how successful it is at emulating stuff. I only got it today and wanted to get this out straightaway so it’s very much a 'first impressions' kinda thing.

Firstly, a little clarification; in the other PGS thread I mentioned that although it was a US product I was charged 20% VAT at the point of checkout. This is unusual for a US purchase, but when I got the despatch note it became clear it was despatched from a German address, so there was no VAT to pay when it came into the UK. I put this in just to reassure any potential UK buyers that you will only pay the correct amount of VAT, there is no more to pay when you receive it.

OK, onto the amp. It comes well packaged in its retail packaging, but also in a branded Positive Grid shipping carton. My first impression on unboxing was this is a quality build. Quite weighty for its size, but not prohibitively so - just a nice solid product. And it’s dinky small - smaller than a Space Echo. It’s covered in a nice tight-grain black Tolex with gold piping (yep, really) between the top and side panels. The piping and overall appearance gives the amp a very retro feel which I really like. There is a pleather strap (embossed with Positive Grid) that is anchored just above centre of each side panel, again, helping to support the retro feel, kind of like an old transistor radio. Fluted black plastic knobs with anodised gold tops adorn the top control panel, and a metal toggle switch for power.

Controls are:

  • Power switch with LED
  • Rotary switch for amp channel selection (Acoustic, Bass, Clean, Glassy, Crunch, Hi Gain, Metal)
  • Digital pots for: Gain, Bass, Mid, Treble, Master, Mod, Delay, Reverb, Output

There is also a tap switch to set the delay, 4 illuminated momentary switches to select 1 of 4 presets (user-definable), headphone out (3.5mm mini-jack) and a Music Volume trimmer (I think this is for the play-along stuff, but I’ve not got to that yet).

The settings are controllable via the Spark app for iOS or Android, but I wanted to see how it sounded straight out of the box. I set the amp selector to Clean and all the tone pots to mid-way and plugged in…

I have to confess to not expecting much, but boy, was I wrong! The sound that comes out of this thing is unbelievably HUGE for such a small unit. I tweaked the tone pots a little and was able to dial in a very passable tone in no time. It just sounded good almost right off the bat. The tap switch let me set a nice rockabilly delay, little tweak to roll the delay back a little, dimmed the reverb a touch and it’s gig ready. I don’t think I’ve ever got a decent sound so quickly.

And it really is a decent sound. It’s hard to believe that sound is coming out of that tiny box. The reverb has a 3D quality to it so I’m guessing the amp is stereo, even more impressive considering its size. I believe it has 4” speakers, but it sounds much bigger. It's marketed as a practice amp, but you could easily gig this amp and at 40w it will hold its own very well.

OK, so let’s look at the app. You can download this for free and play with it in a kind of demo mode without the need to attach an amp. Of course, you won’t hear anything, but you get a feel for how easy it is to operate. First thing you are asked to do is connect to a Spark. If you don’t have one you can skip this part, but if you do just make sure it’s switched on then hit Connect. After a few seconds the handshake is done and you’re rolling - no pairing or 4-digit numbers to worry about.

The app interface is an emulation of a signal chain through various pedals. The default order is: Gate, Compressor, Drive, Amp, Mod, Delay, Reverb. I’ve yet to find out if it’s possible to re-order them (It must be, surely), but I’m trying to do this all without consulting a manual to see how intuitive it is. If I need to consult a manual then so be it…

Tapping on each device in the chain gives access to that device’s control panel. Double-tapping anywhere in the signal path takes you into a device selection mode where you can select between different amp types, delay types, etc. The graphics of the pedals are all typically skeuomorphic with traditional-looking stomp switches to turn them on and off, but you can also do this by swiping each pedal in the signal chain up (off) or down (on). Dead simple.

Of course everything is also named so you know what it's trying to be, but carefully so as not to infringe any IP (the green 3-knob distortion pedal is called Tube Drive - huh, wonder what that can be).

Once you have the sound you want you can save that for later recall and also program it into one of the 4 presets in the amp. This is a great feature as it means if you have a limited palette of sounds (which I do) then there’s little need to ever connect the phone again. Rudimentary controls are provided for on the amp so you can tweak as a room dictates. Having said that, the fact that you have full control within the phone means you can easily get into deeper adjustments if you need to.

I do have a couple of little niggles. The power is provided by a 19v line wart. I’m not crazy about line warts in general, but the output (low tension) side has pretty flimsy cable. I’ve already kicked it free from the amp a couple of times and I doubt it’ll take too much abuse.

Also, the LEDs on the top panel are a little distracting, particularly as the tap button flashes in time with the delay.

But these are very tiny niggles compared to the positives. As I said up front, I’m not an expert in these fields and I’m sure there are some who will disagree, but for $224 + VAT shipped to my door I’m absolutely knocked out. All in all I’m amazed they’re able to do all this for such a low price.

And I've not even got into the play-along stuff yet...


One other small point and something to bear in mind for those that haven't used digital modelling gear. The digital pots are a little odd to get used to. Say for example your knobs are all at five. Then you switch to a program that has, say, the bass knob at 10. The fact that the physical knobs are still at 5 means when you turn one it defaults to wherever it happens to be when it senses movement. So your bass setting of 10 will suddenly jump to just over 5 (if you're turning up) or just under 5 (if you're turning down). This is not a criticism, it's just a shortfall of digital pots. One way round it would be to have limitless pots and an LED scale around the pot that shows the virtual position of the pot. That way they could avoid that odd jumping effect. This all costs money of course, and is a big ask on this product at this price point.


Great review and it goes right along with many I've seen online or youtube. I can't wait to hear what you get from the play along feature and if you dive into original music played with their logic program.


OK then, PG have just taken the interface from their iOS apps - and no doubt all the modeling code - and married it to well-designed hardware. I assumed that would be the case.

I'm impressed that it sounds so biggily impressive out of a pair of 4-inch speakers, but not terribly surprised. There would be little sense in doing this all-in-one thing badly, as they're bound to attract a whole new cadre of players unlikely to adopt a pad or PC app feeding external hardware - and who harbor as much skepticism as hope. They would be quick to jettison the whole thing if it sounded weak with a smug "I knew it would suck."

If PG give you access to all the effect and amp/cab models in the app, you have a palette of hundreds of virtual devices to mixenmatch. And, again, if the interface is as same as it sounds, you just drag the skeuomorph of the device on the screen to change effect order. It should be possible to incorporate splitters and mixers in the virtual signal chain as well, to create parallel effects. And in the pure app, you can also run pairs of amps in stereo. Bet you can in the Spark as well.

I'm curious about the jam-along, generative, and "karaoke" functionality. That will be implemented via coding, of course, and is presumably "new" work on the part of the boffins at PG. (I'm trying to talk British here.) So when considering the economics: how can the box offer so much functionality for so little money, bear in mind that the core coding for the models was done years ago, and has been "amortized" over numerous pure software and software-embedded-in-hardware products. At this point, to PG, all that is essentially free for the burning into chips.

No doubt there's investment in the time and expertise it takes to do that - and to design the circuitry for this particular device - but it's like all the functional content is essentially free to the manufacturer by now. They do keep revising and augmenting all that coding on a regular basis, adding new models and refining behavior and even tone, and presumably the Spark will be as software-updatable as the apps. That's good for the buyer. The same will surely happen with the code base underlying the interactive features.

Just saying that the miracle of function-per-pound (in both weight and currency) will seem a little less miraculous (though still astonishing) when you take into account how much of the company's earlier work can be poured in for next to nothing. The primary accomplishments here are how they've integrated the interface - and the design and manufacture of the hardware itself, which you're reporting as excellent. (Again, when it comes to expense, remember that the amplification hardware itself is almost surely simpler than in a "conventional" solid state amp, as there's no tone stack or other "preamp" functions. The modeling code provides all of that.)

Sounds like a cool tool. Makes me wish I had a use for it.


I tried the drag'n'drop for effects order, no dice. I did a little googling and it appears it's not possible.


Looks like they're up to $299.00 USD now


I tried the drag'n'drop for effects order, no dice.

Well, that's a bummer. That's a fun functionality to leave out.


I can get why anyone would think so. Personally it's OK by me. I'm not a big effects user and certainly have never grasped the alchemy of moving pedals around. I trust they've got them in the right order so that's good enough fo me. Maybe not for others so a little short-sighted to leave it out I guess.

Also, no line out. That's a big shame as that would allow plugging it into a PA and then live use is definitely doable.

I didn't check out any reviews before I wrote mine (nor before buying it) and I just spent an hour or so seeing what everyone else thinks of it. Seems we're of a like mind in the main.


Tim, I just re-read your post. I agree entirely that the modelling is long-since paid for and this is just a new delivery method to continue monetising it (my collection of paid plug-ins is Line 6 and Waves - nothing else, so they've got a new customer in me and I'm sure many others). I think my biggest point was that this is a very well-designed piece of hardware that sounds absolutely incredible for its size. Once the novelty of the karaoke-along features wears off (if indeed it ever wears on) I doubt I'll ever use it again, but purely as a great sounding, extremely portable and eye-pleasing amp, I have to say I'm as happy as I've ever been with a purchase.


I saw the Spark take off on Facebook, much more interested in what you folks think than the FB crowd. That said, I feel antiquated with just a Tonemaster now. (Ha!)


Just found what might be considered by some to be an ‘easter egg’ feature. It’s pretty well documented that the Spark doesn’t include a spring reverb in the modelled effects. But here’s a thing; on certain patches if you give the amp a gentle whack it behaves like It has an onboard spring reverb.

Not sure quite why or how this happens, but I thought I’d mention it.

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