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Studio Electronics SE-3X

Analogue Synthesizer By Dave Gale
Published September 2021

Studio Electronics SE-3X

A long way from their rackmounted Minimoogs, Studio Electronics’ SE‑3X is a four‑filtered, paraphonic monster.

It could be argued that throughout the late‑’80s and early‑’90s, Studio Electronics were partially responsible for keeping the analogue dream alive. During this period, classics such as Minimoogs were demoted to the secondhand ads, cast aside by many as outdated and unfashionable vintage relics. Meanwhile, Studio Electronics were busy creating the Midimoog; a beast of a synth, which contained the guts of the original Mini, but in the convenient state of a fashionable rackmounted synth, and as the name would suggest, fitted with MIDI.

Unsurprisingly, the Midimoog was quite a hit, but it wasn’t until 1993 that Studio Electronics realised that there was a desire for something cheaper, but with similar criteria. Boasting valuable credentials, such as programmability, the SE‑1 materialised, followed a few years later by the SE‑1X.

Next Chapter

Nearly 30 years on from its inception, the original SE‑1 has evolved into the SE‑3X. The similarities between models is reassuring, not least because the architecture draws inspiration from the Minimoog, but with a number of major enhancements that make this 3U rackmounted monster a tempting prospect.

The signal flow begins with three voltage controller oscillators. Each is identical, offering saw‑tooth, triangle and square wave, with the latter being open to pulse‑width modulation. Moreover, it’s possible to activate all three waves simultaneously; this in itself can be useful, but can sound a little strange, due to the intrinsic nature of layering three waveforms at the exact same frequency. Apply some PWM to the square while in this layered state, and you get a really interesting twist to the sound, as though the oscillator is arguing with itself over the exact tuning. Play this in the lower pitch register and you’re in an immediate drone zone.

While in this single VCO state, the SE‑3X easily demonstrates it superior sonic credentials, but it’s through the application of the additional two VCOs that the texture becomes massive. In true Moog/SE fashion, the tuning pots are immediately accessible, making it easy to place the VCOs at the pitch you require. The nature of the default coarse tuning reflects semitone steps, while the liquid crystal display jumps to the tuning page, allowing you to tweak it to your preferred octave or interval. The review model, which is SE‑3X serial number 0001, exhibits a strange pot behaviour, where the tuning doesn’t always settle right on the +12‑octave point, bizarrely nudging between a semitone step either side. I’m assured by SE that it gets easier with experience, as familiarity with the onboard digitised pots increases. The pots are necessarily digital to allow for patch storage, but feel very robust and ‘analogue’. I quickly learn that by overshooting my required value destination, dialling the pot back hits the mark more easily. SE were of course correct!

Fine‑tuning is equally simplistic; by pressing the shift key, the coarse tune pots switch to cent‑based fine‑tune mode, allowing each oscillator to be marginally offset for a thicker texture. Each VCO is equipped with its own PWM pot, and by way of a similar ‘Shift’ technique, the volume of each VCO can be adjusted via the PWM pot. Each VCO is tunable over five octaves, which when added to my 88‑note MIDI controller keyboard allowed for a vast range, from the low‑register audible ‘blip’ to the barely audible high‑note squeal. VCOs two and three are also sync’able, with a simple press of the sync buttons, helpfully located between each VCO.


So to the first of the major new inclusions in the feature set; the SE‑3X offers either monophonic or paraphonic operation. In mono mode, the three VCOs are stacked to present a single note. Granted, this single note could actually be three notes if you set your VCO tuning in such a way that you hear a chord, but triggering will always occur from a single note.

Where paraphonic differs is by offering the performer the potential to use each VCO for its own played note, for playing triads or chords with up to three notes. This effectively turns your SE‑3X into a very basic polysynth with three‑note polyphony, but the paraphonic ethos means that the synth is reliant on a single envelope and amplifier. It’s better to think of it as a monosynth with basic poly benefits!

In play, I found that it was essential to bring any notes off with absolute accuracy, otherwise the result could be a retrigger from the last note standing. By tuning the VCOs in different octave registers it’s possible to get some really interesting and unexpected paraphonic voicing results, which creates a welcome degree of unpredictability, leaving me to practice my keyboard technique for clean note‑ends. There’s always a DAW editor on hand to help if you want to get those ends of notes to play nicely in a production.

Activating paraphonic mode isn’t overtly obvious. As I was reviewing without a manual, it took a degree of menu diving to find it, and even then, it’s not immediately obvious. Hiding in the ‘Note Priority’ section, SE have also engineered a keypress involving the shift key and the two VCO sync buttons. It’ll be one of those ‘need‑to‑know’ operations, although the vast majority of procedures are immediately accessible from the front panel, with the display reacting to guide your path, through clues about parameter values.


The next major enhancement could probably be regarded as the main event: SE have long been known for their attention to detail, thanks to the incredible knowledge of the inhouse designers Tim Caswell and Greg St Regis. This knowledge manifests itself in filter design which nods firmly in the direction of the classics, but with helpful technical additions for modern deployment. The net result is that the SE‑3X features four different filter designs, to cater for just about every subtractive whim.

All of these filters are billed as ‘SE classic’ designs, adopting reverence to the originals but with enhancements along the way. An Oberheim SEM‑styled 12dB filter, offering both low‑ and band‑pass filtering is first in line, followed swiftly by a 24dB Moog ladder filter. Next is a 24dB ARP filter, with the perfect tail‑ender being the Roland Juno/Jupiter filter, in both 12dB and 24dB forms. There’s also a further ‘Mix’ mode which combines both of the Roland filter models.

The ability to audition all four of these filter designs in such quick succession leads to some pretty interesting revelations. At first sight, the similarities are very striking, particularly while comparing the likes of the ARP and Roland 24dB filters, but it underlines the necessity to consider the VCO construct and tuning, while curating a patch. By way of example, a pseudo Juno or SH‑101 patch requires a perfectly tuned saw and square wave, alongside a sub oscillator below, for that classic Roland colour. But this synth offers far more than straight facsimile, with the addition of the blended Roland filter providing a formidably p otent sonic punch. That familiar Roland resonant squeal is exceptionally easy to reproduce, with the characteristic low‑end signal drop behaviour being open to a little repair, thanks to two overdrive settings on the backend of the module. The overdrives are designed to offer a ’70s vintage tone, alongside a harder ’90s fuzz, which certainly feels entirely reminiscent of my trusted old MXR distortion, from days/years gone by.

Unmistakably a Studio Electronics synth, the SE‑3X takes up 3U of rack space and weighs in at just shy of 5kg.Unmistakably a Studio Electronics synth, the SE‑3X takes up 3U of rack space and weighs in at just shy of 5kg.

Coming back to the filters themselves, the Moog is entirely assured, which won’t come as a huge surprise, being something of an SE calling card. It is rich, plentiful in texture and very classic, with copious amounts of bottom‑end creaminess. It’s hardly a surprise that previous SE boxes have become secret‑weapons‑of‑choice for many media folk, providing a fuss‑free and quick solution to padding out the bottom end of a string section. It sounds rather awesome!

However, with my modular head on, I have always gravitated to SE’s beautiful ARP 4075/4072 filter. This is probably my favourite on the device, for mainstream duties, providing an incredibly rich texture and crisp brightness, as appropriate. The bottom end is just ‘there’, even while applying resonance, and that’s without overdrive. Finally, there’s the Oberheim filter, which is switchable between low‑ and band‑pass modes, adding a wispy filter colour to the favourable options already on offer. All the filters are undeniably impressive.

The process of filter selection appears simple, but does actually require a degree of explanation. In the SE‑3X’s default state, the OB filter is active, with switching between low‑ and band‑pass modes through the on‑screen menu. Directly below the filter cutoff pot is a button which, when illuminated, activates the other filters. These are in turn selected via a small pot, which selects Moog, ARP and the three styles of Roland filter. It’s another case of ‘easy once you know how’!

It’s also worth stating that with reference to my previous thoughts on the filter similarities, altering the initial VCO states or working with heavily resonated filter settings will radically change the tone, particularly if you bring the distortion into play. Creating drum, percussion and whooshing patches on this synth really amplifies the diversity of filter colour, and while I hate the Swiss‑army‑knife analogy, in many respects that’s exactly what you have, and that’s just within the filter section. The resultant colours are beautiful, musical and gnarly; it’s purely where you fancy going first!

Mix & Mod

Being something of a hybrid, the modulation elements have not been left scrimping. The SE‑3X provides two envelopes, which default to the amplifier and the filter. Envelope 1 is equipped with an amount pot, for easy application in the direction of the filter cutoff. Envelope 1 and 2 can be switched to a further two independent envelopes, 3 and 4, by pressing the accompanying illuminated button. These can be routed via the menu display to a number of locations. It’s also worth mentioning that the envelopes are all four‑stage ADSR designs, which is eminently sensible, and have been improved from previous SE‑1 designs to provide greater snappiness. They can also be switched between two styles of exponential shape and linear mode, and also inverted, all of which is executed through the menu display.

Modulation is also accessible via three LFOs, which can all freewheel or sync over MIDI. The first is assigned to pitch by default, but all routings may be altered through the menu.

The display and menu hierarchy does require a little bit of getting used to, and it would certainly be fair to say that SE have made some significant improvements to the original SE‑1 in order to speed up certain procedures. For the most part, the display jumps to the place where you would like to be upon alteration of a pot. It can sometimes feel a little tedious trying to get back to the main patch window, although at the time of review, further enhancements were being made to the OS to make life even easier.

There are a couple of operations that require a small menu dive, notably the activation of white noise and ring modulation. Both are highly desirable, with ring mod a firm favourite in the paraphonic environment, where overtones and harmonics become apparent through the playing of certain musical intervals.

The SE‑3X offers portamento, in both linear and exponential form, mirroring the examples that might accompany the filter/synth line‑up. There’s also a rather nice auto glide function, which provides a swoop in pitch, from either above or below the triggered note.

The SE‑3X sounds expensive, which is just as well, but I would wager that it will also last a lifetime, both as a device and as a powerhouse of subtractive creativity.

It’s A Rack!

Studio Electronics are the synthesizer equivalent of a great independent coffee outlet, wine merchant or fish and chip shop; the people that know about their products are real devotees and will travel far to get their flavour. This is despite adopting a somewhat boutique status, and there’s no pun intended, given that SE worked with Roland on the very successful Roland SE‑02 Boutique module.

The SE‑3X is not a cheap synth, while only being available in rack form, in a market where there are plenty of cheap analogue clones that might make similar claims. The difference seems to be that this is a box built by engineers who know exactly how to build a synth from the ground up, masterminding numerous enhancements along the way; not because the originals weren’t good enough, but to add a new dimension and bring the charm of those vintage devices to a production‑ready age. The SE‑3X sounds expensive, which is just as well, but I would wager that it will also last a lifetime, both as a device and as a powerhouse of subtractive creativity, which will always sound in vogue for many different styles of commercial music.

MIDI Control

Given that the manifesto for the SE‑3X is steeped in vintage charm, it’s great to know that the MIDI implementation is significant. Apart from the usual things that you would expect, such as notes, pitch wheels and modulation, there’s a vast number of parameters that are controllable through MIDI CCs. At the time of review, some of these numbers were being tweaked to bring them into line with more mainstream MIDI CC numbering, but control extends from the basics such as filter control, through to oscillator and envelope control, and much more besides.

Place it in a rack that’s out of reach, and you can still program the SE‑3X to dance to your tune from your DAW. Four banks of ROM presets reside alongside four user banks, each with 99 locations, so if tweaking your sound via DAW is not your thing, saving and recalling your patch is very easy.

The Rear Panel

Studio Electronics SE-3X rear panel.

The SE‑3X is a comparatively simple beast, and this is mirrored by the impressively simple‑but‑rugged casing, and the limited connectivity. MIDI is handled conventionally via In, Out and Thru 5‑pin MIDI sockets. There’s a single quarter‑inch mono jack output, located next to a mono audio input, although a note command must be sent to the VCA in order to hear the external input. This makes it highly usable in conjunction with other synths or modules. The Power supply is built in, connected via a traditional IEC kettle lead connector, for perfect grounding.


  • It feels reassuringly vintage and contemporary, in equal measure.
  • Classic signal path and architecture.
  • Equipped with four beautiful and impressive filters.
  • The paraphonic operation adds an appealing three‑note dimension.
  • Oozes production‑ready sounds, with total timbral control.
  • It sounds fantastic, with true sonic depth and weight.


  • Available only in 3U rackmounted form.
  • Menu navigation takes some getting used to.
  • OS update only available via EPROM replacement.


The sound of the SE‑3X is the unashamed talking point for this product. It is impressively detailed with depths that, like its forerunners, will find their way on to plenty of commercial tracks. From hip‑hop to soundtrack, the SE‑3X brings a flexible subtractive sound, right to your door.