Product Review: Positive Grid Spark Mini

Silly me, I thought the Positive Grid Spark Mini was a fairly new product, but my resident guitar repair guru and guy-who-will-try-to-fix-anything about town, Brian Stewart (Tree Strings Music), has already repaired one in his Red Wing shop. I haven’t yet heard what the fault was in that unit. I ordered a white one from Amazon, thinking it might be a fun practice and outdoor jamming amp. I’ve had it about a week and, sadly, the fun is wearing off fast. The good and bad news is that almost everything about this amp is driven by a phone/tablet app, iPhone or Android. The good is that it has hidden power if you’re willing to climb the usual steep software learning curve. The bad is, like most apps, it’s glitchy, unpredictable and often counter-intuitive, almost completely inflexible, and very dumbed-down while pretending to be a product for the sophisticated, discriminating guitarist (the ultimate oxymoron?). A lot of the positive reviews you will find for this amp begin with something like “I’m new to guitar and have only been playing about a few months . . .” It’s easy to like or even love something if you don’t have anything to compare it to. In my case, it’s hard for me to look at any product with the eyes of a newbie. So prepare to be disappointed if you’re hoping for that kind of bubbly, happy-talk review. At 74 and after 50 years in various areas of pro audio and music, there is nothing new about me except for the crap that keeps popping up every time I have a doctor’s appointment. Having spent 20-some years in test and reliability engineering I tend to find more things wrong with software than right.

 

You can’t beat the Mini’s physical controls for simplicity. On the top of the amp chassis, you get 4-position Preset switch (Rhythm, Lead, Solo, and Custom), a Guitar volume, a Music volume control (Bluetooth or Aux In signals), and a guitar input. The back of the chassis has 3.175mm (aka 1/8”) Line Out and Aux Input jacks, a USB-C port for charging the battery and (sometime in the future) a functioning digital audio interface), a Bluetooth “Pair” switch (the Pair switch also fires up a rudimentary guitar tuner), and a power switch. The amp comes with a cute leatherette strap and a pair of buttons to attach the strap on the side. The amp is a 10W Class-D unit that, supposedly produces 90dBSPL at 1m. The cabinet has two 2” speakers and a bottom-facing passive radiator. The 3Ah battery supposedly provides power for 8 hours (on mid-to-low power output) and charges from empty to full in 3 hours. The firmware contains “33 Amp Models, 43 Effects, (Noise Gate, Compressor, Distortion, Modulation/EQ, Delay, Reverb – fixed in that order) and the USB interface is a 44kHz/16 bit A/D. You also get a a free download of PreSonus Studio One Prime recording software with your original purchase. Registering for your software is the closest thing to registering for warranty with Positive Grid. You can buy (for $110) a Spark Control footswitch to either control the presets, turn on and off various virtual pedals, or a combination of those functions. The amp is 146.5 x 123 x 165 mm (5.76 x 4.84 x 6.49 in) and weighs 1.5 kg (3.3 lb).

As usual, the included paper “Quick Start Guide” is close to useless. Not so typically, Positive Grid hasn’t provided much in the way of useful information on their website, YouTube, or anywhere else. Figuring out the app and the various features of the amp that are only accessed through the app is up to the buyer.

For a beginning guitarist who doesn’t know any other musicians, some of the Mini’s app features are probably fun-to-useful. This “screenshot” is really a compilation of three different screens as typically displayed on a phone. The middle one is an example of a dumbed-down imitation of a fairly common DAW guitar pedal screen; like the one in Logic Pro. A big difference between the DAW pedal boards and the Spark is that you can’t reshuffle the order of the pedals to suit your purposes.

After spending considerable time playing with the various pedals I can say “they work.” The compressors in the Comp/Wah section aren’t up to DAW standards, but they are probably as good as most hardware pedals. The “Wah” function, also included in this group, is “Temporarily Disabled.” As usual, I don’t like the distortion (Drive) pedals much, but I rarely do. About half of the Drive pedals are red-flagged, which means you’ll have to spend $20 or more to enable those pedals on your device. So it goes for the Amp models, too. Most of the red-flagged amp models are variations on the mediocre Marshall models. The Mod/EQ models are predictable and not bad. The Delays are ok, except for the absence of a multi-tap delay. The Reverbs are typically pretty good, since digital reverb plug-ins have been fairly well staked-out territory for at least 20 years. I didn’t find a favorite from the verbs, but I didn’t find anything I hated either.

Irritatingly, with my Samsung tablet and the Samsung Music player, anytime I open the Spark app the music player starts playing something from my current playlist through the Spark Mini. Before you start babbling about some “play on Bluetooth connection” toggle in the player, get a grip on yourself. No other Bluetooth device that I own has this behavior: from consumer buds to Shure in-ears to three different Bluetooth speaker systems. It is a glitch in the Spark app and that has been logged by Positive Grid’s customer service and I wasn’t the first to make the complaint. If everything else was excellent this wouldn’t be a deal-breaker, just unpredictably irritating. (If it does this when I first open up the app, will it spontaneously do the same during a gig?) Yes, I could turn off the Music volume, but if I am using it as a backing track at the time it sort of defeats the purpose of that function.

With that out of the way, my impression of the guitar amp is somewhat positive. I’m not fond of electric guitar distortion in the usual buzz-box fashion, but some of the amp models deliver decent slightly over-driven sounds with the kind of amp EQ and tone you’d expect from what I’m guessing are the amps being modeled. Some of the setups both by other users and Positive Grid are fair-to-decent. I had some high hopes for Pat Metheny style sounds, but the lack of multi-tap delays squashed that. You could just add a pedal delay up front but that would defeat my purpose. I have an old MacBook Pro with MainStage that will do everything this unit does with a ton more effects including my multi-tap delay that I’d rather use with a small wired power speaker than add a pedal that is almost as big as this amp.

And speaking of power, I wouldn’t be surprised if the Mini an produce 10W, but the distortion at that output would be objectionable. That goes for the spec’d 90dBSPL@1m acoustic output, too. At any volume over a moderately loud voice or a strummed full-size acoustic guitar, the bottom end of this amp clips indecently. It is not a pleasant distortion, either. It is the usual splatting sound of digital clipping. That was the straw that broke the back of my interest in the Positive Grid Spark Mini. There were moments when I thought I was about to find the sweet spot for several of the Presets but “almost there” was as close as I got to something useful. When the amp sounded good, it was too quiet to compete with a couple of acoustic guitars. When it was loud enough to cut through a small instrument crowd, it sounded awful.

For a beginning practice amp the Spark Mini isn’t bad. Most beginners, however, will have a terrible time with the mediocre application software that is an absolute necessity for using the amp. Advanced users will be frustrated with the user-hostile programming of the app and disappointed with the little amp’s small performance.