Studiologic Sledge 2 review: Vast improvements make it a serious bang-for-buck synth

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I first noticed the Sledge a couple of years ago at the NAMM Show. It was hard to miss thanks to its Tonka-yellow livery. At the time, I thought it was a decent sounding virtual analog synth, but given its nearly 2,000-dollar price, I was more interested the real analog gear on display. Now the improved Sledge 2.0 has arrived with a street price just under an even grand, so it’s time to give it another spin. Like the original (reviewed Nov. ’13), the Sledge 2.0 sports a Waldorf-designed synthesis engine, but with more polyphony, expanded features, and user sample import via USB.


Love or hate the cosmetics, the Sledge 2.0 is actually a very nicely designed synth. Its most impressive aspect is its large array of front-panel knobs and switches. In fact, almost everything (except the MIDI and arpeggiator features) is available for real-time tweaking. This is one of the biggest draws for me as a synth player and, in practice, it makes sound design and patch editing quite enjoyable. What’s more, the knobs are rather substantial in size, with important knobs like filter cutoff and wavetable selection even larger.

The casing is plastic, which makes the Sledge surprisingly lightweight. Even so, it feels quite sturdy. All I/O is on the left cheek: USB, MIDI, expression and sustain pedal inputs, stereo outs, and a headphone jack. I found this easier to manage than reaching around back of the unit during setup, but you’ll need to do some cable management if placing the Sledge on a tier above another keyboard.

The signal path is straightforward: three oscillators feed a multimode filter followed by an amp, with three LFOs and a standard complement of effects at the end of the chain.


All three oscillators include saw, square, triangle, sine, and variable pulse as their core waveforms, but each also has individual extras, giving the synth a much more complex sound than several of its competitors.

Oscillator 1 also offers wavetable synthesis, with scanning through the table handled by the same knob that controls pulse width. Many of the wavetables are derived from the PPG Wave, a really nice inclusion for vintage buffs. Newer tables are thanks to Waldorf’s participation. While many of the wavetables sweep smoothly, some include a touch of the zippering found in the original PPG. It was great to hear some of these classic morphing textures on a modern synth and it’s a fantastic resource for sound design.

Oscillator 1 also includes multisampled piano, Rhodes, Wurly, Clavinet, acoustic bass, and a small selection of odd but useful drum loops. All of these sampled instruments have a late-’90s workstation vibe, but sound fine and would definitely work in a pinch. Studiologic informs us these are demo sounds and that new sounds will be downloadable from their website.

As an added bonus, you can now load your own sample data into oscillator 1 over USB via a free downloadable app called Spectre. The user-accessible sample memory is a mere 60MB. That’s tiny by today’s standards, but the intent is for your samples to be raw materials for synthesis, not your go-to acoustic instrument emulations.

Oscillators 2 and 3 include FM, with oscillator 2 modulated by oscillator 1 and oscillator 3 modulated by oscillator 2—and the results are even more dramatic when both oscillators are in FM mode. In addition, oscillator 2 can also be hard-synced to oscillator 3 for those edgy, squawky sounds.

The whole combination of virtual analog, wavetable, sampling, FM, and sync gives the Sledge 2.0 oscillator bank loads of sonic horsepower, and it’s capable of everything from traditional analog textures to extremely nuanced digital atmospheres.

Filter and Amp

The Sledge 2.0’s multimode filter includes lowpass, bandpass, and highpass modes and a choice of 12dB or 24dB slopes. The resonance sounds quite juicy at medium settings and will self-oscillate—loudly—at maximum. There’s also a Drive knob for adding a bit of distortion.

The filter has a dedicated ADSR envelope, with intensity controlled by a bipolar Amount knob. Interestingly, I heard audible zippering—from turning the Amount knob, not the envelope stages themselves. In 2015, this surprised me. Then again, envelope amount isn’t usually something you reach for in live performance, so you’ll likely notice this only when tweaking patches.

The amp section includes an ADSR envelope and a Velocity knob, and that’s it. At first, it looked as though the only parameter you could modulate via velocity was volume, but the most recent firmware adds filter cutoff as well—though this is not clearly documented.


The Sledge 2.0’s modulation section includes assignments for three LFOs, one of which is controlled by the mod wheel. The LFOs offer the expected waveforms—saw, square, sine, triangle, and sample-and-hold—and can be routed to oscillator pitch (in various combinations of oscillator groupings), filter cutoff, volume, or pulse-width/wavetable, and the depth knob is bipolar. As a group, these LFOs are capable of adding some lovely animation to filter sweeps and pulse width modulation. For wavetables, it gets trickier, as some of the zippering artifacts become more pronounced when modulated by the LFO.

Then there’s another option called “ramp.” At first I thought this might be an alternative sawtooth until I realized it only cycles once then stops. That is, it’s an adjustable one-shot slope that can be applied to parameters instead of the LFO. This a funky yet essential addition, in light of the fact that neither of the Sledge 2.0’s filter or amp envelopes can modulate additional parameters.


At the end of the chain are two effects units. The first slot is for effects like chorus, flanger, and phaser, and the chorus sounds especially nice on heavily detuned oscillator configurations. The second effect unit is capable of delay and reverb at once, both of which are one-knob affairs.

Also on hand are niceties like single and multiple envelope triggering, glide being available in both mono and poly keyboard modes, and a fat unison option. More importantly, you can now quickly set up splits and layers for live gigs. There’s a two-part maximum, but the old Sledge couldn’t do it at all. Also, an arpeggiator can sync to external tempo via MIDI or USB. Finally, a free desktop app called Sound Mapper serves as a basic patch librarian.


Over several days of testing, I really grew to like the Sledge 2.0’s character and versatility, and was able to quickly whip up fresh new sounds thanks to the front panel with its comfortably oversized knobs. Its oscillator bank is capable of an astonishing range of virtual analog as well as unashamedly digital textures, many of them massive. The paucity of modulation routings is offset by the presence of three LFOs, which combined offer a lot of animation possibilities. It’s also a baby PPG if you’re a fan of classic ’80s sounds.

The biggest story here, though, is polyphony for the buck. The Sledge 2.0’s 24 voices are more than what any real analog polysynth offers at any price, and competitive virtual analog hardware starts at about $300 more (for a KingKorg) and goes up from there. If your gig demands big chords, splits, and layers, this makes the new Sledge a serious contender.


Three versatile oscillators with virtual analog waves, digital wavetables, sampling, FM, and sync. Wavetables are based on the vintage PPG Wave. Can load user samples. Knob-per-function panel layout. Integrated effects. 24-voice polyphony.


Turning some knobs causes audible zipper noise. Limited envelope modulation. Sample memory capped at 60MB.

Bottom Line

Vast improvements over the original Sledge make version 2.0 a bang-for-buck leader among “synthy” synths.

$1,799 list | $999.95 street |