Even beyond the patch matrix, though, the SYNTRX and Synthi A have a lot in common. While the layout is ever-so-slightly different, the core features are almost the same. You have three oscillators, with two different wave shapes each, one of which is designed primarily as a sub oscillator or an LFO and has a much lower frequency range. There’s a noise generator, a resonant low pass filter, a ring modulation circuit, a spring reverb unit and a unique take on an envelope generator that both EMS and Erica Synths refer to as the trapezoid. Both also have built-in speakers, a mechanical VU meter and an assignable joystick for manually controlling parameters.
Again, with that much in common, you’d be forgiven for assuming this is a straight clone. But the SYNTRX does add some notable features. For one, modern amenities like presets and MIDI support. But Erica Synths added a feedback loop to the reverb and there’s a sample and hold circuit. You’ll also find a few more options for how the oscillators and the envelope generator function. For instance, oscillator one and two can be synced for easy unison sounds, or you can turn key tracking off on oscillator three to get a more consistent LFO. There’s also a three-octave switch on oscillator one to increase its range.
These might sound like minor changes, but they give the SYNTRX a much broader sound palette. And, while I don’t have an original Synthi A to compare it to, based on demo videos I’ve seen, the SYNTRX is a little more abrasive sounding. Not that you can’t smooth out its rough edges, but it’s definitely strongest when it comes to giant basses, slightly atonal pads and sci-fi bloops.
The bass tones in particular are huge. Oppressive even — it sometimes sounds like the instrument is about to explode. The saturation from overdriving the filter is just fantastic and the oscillators themselves are rich sounding when combined. Even the ring mod circuit is surprisingly musical. Ring modulation has a reputation for being atonal and I’ve often heard it compared to a broken church bell. You can definitely push the SYNTRX’s ring mod circuit into those areas, but it’s a lot easier to get usable sounds out of it than you’d expect.
Same goes for the spring reverb. Generally, I do not care for spring reverb. It’s a perfectly fine effect when deployed properly, but bad spring reverb (and there’s a lot of bad spring reverb out there) sounds two-dimensional and toy-like. This one, on the other hand, is rich — almost an instrument on it’s own. You can bang the side of the SYNTRX and hear the actual spring clanging around inside. And if you crank up the feedback it releases otherworldly moans and howls.
My only complaints, sound wise, are that the line between very subtle and overwhelming on the reverb mix is thin, and the two primary oscillators can sound a little flat individually. They really benefit from external effects, but, truth be told, most synths are better with some effects.
The SYNTRX is more than just a synthesizer; it’s also possible to use it as a sub mixer and as an effects processor. You can feed your voice through the ring modulator to imitate a Dalek or run a drum machine through the filter. And there are actually three filters: the voltage-controlled low-pass filter, and a pair of output filters on each channel for last-minute sound shaping. While you can definitely use the SYNTRX in stereo, more often than not I’ve used the second output to filter and overdrive a second instrument like a drum machine.
Because the SYNTRX has built-in speakers it’s also completely self-contained. You could, in theory, perform with just the SYNTRX and nothing else. Or connect two instruments to the inputs around the back (say, a drum machine and a second synth), and use it as both a mixer and an amplifier for a more fleshed-out setup. The speakers are pretty decent, too. They don’t quite capture the crushing lows that the SYNTRX is capable of, but they’re decently loud and clear — slightly better than what you’d find inside a small smart speaker. So, definitely not studio quality and they wouldn’t stand up next to a live drummer, but you could probably get away with relying on them as the world’s oddest subway busker.
The joystick at the bottom is also worth paying attention to as it opens up a world of possibilities for manipulating sound. You can assign multiple parameters to each axis and then dial in their sensitivity independently. You can also attenuate the connections on the matrix in steps of 25, 50 and 75 percent by pressing the left navigation encoder, instead of the right (which just makes a 100-percent strength connection). This means you can put both the filter frequency and the decay on the X axis but have small controlled changes to the note length, while sweeping through the whole frequency spectrum.