Review: Pittsburgh Modular System 10.1

Review of the Review: Pittsburgh Modular System 10.1 modular synthesizer
Image placeholder title

As I began my journey into the world of modular gear, ONE OF THE first synths I picked up was a Doepfer Dark Energy Mark I. Its compact size and small array of CV I/O was the perfect gateway drug for my addiction to wires. It was—and still is—a great sounding box for the size and price.

But within a month or two, I started bumping into its walls. Despite a capable collection of jacks, there was no voltage mixer or mult patchbay for attenuating, splitting, or merging CVs—all crucial elements in a modular starter rig. So when I saw Pittsburgh Modular’s new System 10.1, I immediately felt a twinge of belated buyer’s remorse. Spec-wise, the System 10.1 is the perfect entry-level modular synth and includes the majority of essentials for diving into the voltage-controlled universe. The only remaining question: How does it sound?


The core of the synth, the Synthesizer Box module, is a single-oscillator affair with a few exotic extras that set it apart from many of its competitors. For example, in addition to triangle, sawtooth and variable-width pulse, it includes a waveform called Blade, a switchable alternative to the sawtooth. Recording it into my DAW, it appears that the Blade wave is an inverted saw that’s an octave higher than the other oscillator waveforms.

The Blade wave gets a bit more interesting when you apply LFO modulation to it; the waveform starts to morph between a squarelike shape and the inverted octave saw, resulting in some really cool harmonic motion. To be candid, my tests were extremely informal here. The big takeaway is that the Blade wave is a unique and useful addition to the oscillator’s spectral output and helps give the System 10.1 a sound that’s normally associated with dualoscillator synths.

There are a few other interesting oscillator amenities, as well. Like the fact that the triangle wave seems to be slightly out of phase with the square, resulting in a lowering of volume in the first harmonic when it’s added via the System 10.1’s waveform mixer. There’s also a simple sub-oscillator that tracks the main oscillator with a square wave an octave lower. This sub isn’t available on the mixer, however. Instead, it relies on a three-position switch that toggles between off and two hardwired volumes.

As for the lowpass filter, it combines VCF and VCA functions into several different modes: VCA only, lowpass and the classic Buchla-style “lopass gate.” In VCA mode the cutoff knob behaves like a cross between a volume potentiometer and an overdrive circuit, with high values adding a lot of gain to the signal. In lowpass mode, it functions like a standard lowpass with some of the filthiest resonance I’ve ever heard. It’s absolutely monstrous in all the right ways. In lopass gate mode, the resonance knob is inactive, but the overall result is extremely warm and rich.

As for enveloping, the System 10.1 filter can be set in one of two modes, Mod and Ping. In Mod mode, the unit’s standard ADSR functions as expected as a cutoff modulator. In Ping mode, the ADSR modulation is bypassed and replaced with an extremely sharp and thwippy decay that’s fantastic for adding transients to your sounds. Interestingly, the ping also modulates the filter when it’s in VCA mode, adding a sharp transient to the volume envelope when active.

The envelope itself is a slight variation from the usual ADSR, with knobs for attack, decay and release, but an on/off switch for the sustain function. In practice, this was a minor caveat. As for the LFO, it’s a standard triangle wave when hardwired, but includes outputs for both square and triangle in the synth’s patchbay. Finally, there’s a Glide knob for adding lag to the keyboard’s CV. I was a tad disappointed that this wasn’t accessible from the patchbay as a lag generator, but it’s not a huge issue in this context.

Modular Features

The rest of the panel is festooned with ins and outs for pretty much every synth parameter, including outputs for each of the individual waveforms and sub-oscillator. In addition to the synth’s jacks, the Mix/Mult module provides three logarithmic potentiometers that include dedicated I/O jacks. The logarithmic behavior makes them best suited for audio, but you can also scale external voltages with them, if needed. This section is best thought of as a secondary mixer, but as with all modular gear, imagination and experimentation is the key. At the bottom of the panel is a pair of passive mults.

MIDI3 is a two-channel MIDI-to-CV module with additional outputs for velocity and a single CC output. This can be configured in one of three ways: with a single monophonic output where CV1 and gate 1 being mirrored by CV2 and gate 2; duophonic output with the two voices being sent to separate CV and gate outputs; or a dual monophonic output with each pair of CV/gates responding to its own discrete MIDI channel. In addition to the MIDI features, there’s also a synched clock with its own tap tempo button and an integrated arpeggiator. The Outs module has dedicated 1/4" headphone and stereo line outputs.

Fig. 1: For an extra C note, the Pittsburgh Modular System 10.1+ includes additional empty slots so you can customize your rig to meet your exact needs There are some cool tricks you can do with all of this I/O, such as using the envelope to modulate pitch, pulse-width or the Blade wave, or create drone patches with slow, evolving modulation from the LFO. But if you want to go further, you’ll need to expand the system with additional modules. This is where the System 10.1’s bigger brother, the 10.1+, comes in (see Figure 1). It includes all of the features of the standard 10.1, as well as six additional empty Eurorack slots (with panel covers) so that you can add more modules from Pittsburgh or other manufacturers. Best of all, the 10.1+ is a mere $100 more than the base unit, making it an extremely attractive alternative.

Image placeholder title

Get Patched

All in all, I was thoroughly impressed with the System 10.1 as a starter package for those looking to explore modular synthesis. The Synthesizer Box module, alone, is capable of some truly massive sounds that have unexpected girth and depth, which makes it a worthwhile contender even without the impressive complement of essential modular tools.

The System 10.1 is a no-brainer as your first modular component. That said, I’d definitely splurge the extra hundred bucks and snag the 10.1+ because of its extended width. This way, you can immediately begin your quest for additional modules. And trust me, that quest will begin far sooner than you expect.

Snap Judgment

Pros Ability to create rich, complex sounds in a small footprint.


Bottom Line

The perfect starter synth for modular adventures.

$799; $899 for the System 10.1+