Moog Muse

A Moog polysynth is always a big event, but is the Muse the inspiration you’ve been waiting for?

There was a time in the early 1970s when all synthesizers were called Moogs, no matter which company built them, just as all ballpoint pens were Biros and all vacuum cleaners were Hoovers. But despite being the world’s most recognisable synthesizer brand, Moog have hardly been prolific and, if you list their polyphonic instruments from the past 55 years, you’ll find that there have been just seven, two of which weren’t publicly released, and another of which wasn’t a polysynth at all. So today I have in front of me Moog’s eighth (or maybe fifth) attempt to capture the hearts and minds of the polysynth market. I wonder whether it will succeed.

While neither as large nor as heavy as the Moog One (with which it shares some features) the Muse is still a chunky beast weighing in at 14.5kg and, notwithstanding some wobbly faders that hark back to the days of the Rogue, Liberation and Opus III, it feels solid and robust. Its 61‑note keyboard offers both velocity and aftertouch sensitivity but neither polyphonic aftertouch, nor MPE, nor the more exotic performance capabilities that recently appeared elsewhere. So, if you want to control this with that while wiggling something else, you might need to look somewhere else.

Despite boasting almost 200 controls, its panel is clear and (in my view) very attractive, and its menus — many of which are accessed using the triangular buttons in the voicing panes — have just a single tier, which helps to keep things simple. All of the housekeeping is carried out in the Programmer section toward the centre of the panel and, while small, the monochrome screen is adequate if you don’t mind scrolling up and down a bit.

The Signal Path

The basic sound generation unit of a Muse sound is the Timbre, and this can be polyphonic, monophonic, or unison monophonic. A patch contains two Timbres and you can switch between these, split them or layer them. The eight voices are then distributed according to your choice from the various voicing modes.

At first glance, a Timbre appears to be based upon a dual‑oscillator‑per‑voice architecture, but the powerful Modulation Oscillator offers an audio mode and tracks the keyboard perfectly, so triple‑oscillator patches are never far away. Oscillators 1 and 2 are based upon those used in the Voyager and, in addition to the standard facilities, they offer sync and bidirectional FM for a wide range of clangourous noises. The Modulation Oscillator is also based on the Voyager design but generates a different set of waveforms and can be disconnected from the keyboard for constant modulation rates and drones. You can use it as a modulator in either range and it provides eight simultaneous modulation destinations directly from the control panel. Glide is also provided. It offers linear constant rate, linear constant time and exponential options, and you can direct it to any selection of the three oscillators as you choose.

The audio mixer lies next in the signal path. We often take such devices for granted, assuming that they sum the signals presented to them without imparting any sonic characteristics, but that’s not the case here. The Muse’s mixer is based upon the Moog CP3 module and mixes the outputs from all three oscillators, the osc 1/osc 2 ring modulator (which was inspired by the Moogerfooger MF‑102) and the white‑noise generator. At low levels, it does this without clipping, but you can overload it to distort and fatten the signal. Interestingly, you can create DC offsets in the mixer to cause it to clip more asymmetrically, and this creates a further range of distortions.

Next come two 24dB/octave filters based upon the 904a filter module. The difference between them is that filter 1 has high‑pass and low‑pass modes, whereas filter 2 is dedicated to low‑pass duties. Both offer the expected facilities, but there are just three keyboard tracking options available from the panel, although you can obtain anything ranging from zero to more than 100 percent using the menus. You can use either or both filters as additional oscillators, which means that you can have up to five sources in a Timbre, even before you invoke the ring modulator and noise. There are three signal routing options — serial, stereo and parallel — and you can link the filters so that Filter 2’s cutoff knob adjusts both equally, allowing you to use them as a single notch or band‑pass filter. Unfortunately, the Muse has no audio inputs, so you can’t use its filters as external audio processors.

The Muse’s VCAs are based upon the Moog 902 module, but implemented in stereo so that you can pan voices or Timbres within the stereo field. You can even link the phases of applied LFOs to the pan position, which is a novel idea, and the VCA menus offer a gain offset so that you can create drones and other effects. Following this, the output section offers independent levels for the main audio and headphone outputs, a mute for the main outputs, and a simple 6dB/oct high‑pass filter to remove deep bass that might interfere with other instruments in a mix.

Paralleling the path between the VCAs and the outputs section, the Diffusion Delay is a digital effect unit that, in addition to stereo delays and ping‑pongs, can create diffuse effects that approximate reverberation. But it’s unable to create choruses and other modulation effects because — at least at first sight — it contains no LFOs to sweep the treated signals. Nonetheless, the manual mentions ‘chorused diffusion’, so I asked the chaps at Moog what was going on. They told me, “The character knob is bipolar. If you turn it clockwise from 12 o’clock you wind up with non‑chorused diffusion (ie. the sound is fed through a diffusion network made up of 24 individual delay lines), and if you turn it counter‑clockwise you obtain chorused diffusion where six LFOs are round‑robin allocated to modulate the delay times of the 24 delay lines.” These LFOs could in principle offer all manner of opportunities for choruses, flangers and ensemble effects and, when I asked about this, they added, “We will be allowing the delay to be modulated in the modulation map soon. We will have a post‑launch update to address this before long.” That sounds promising. Other settings allow you to adjust the nature of the diffusion, select which Timbres are treated (or not) and whether the resulting effect is sent to the main outputs, the headphones, or both. If you bypass the Diffusion Delay, the audio signal remains in the analogue realm all the way from the oscillators to the outside world.

Modulation

At first sight, the Muse’s digitally generated contours appear simple, with a dedicated ADSR (whose default response is modelled on the Moog 911 module) directed to the filter cutoff frequencies and another directed to the VCA gains. However, for each contour, you can choose the shape of the curve for each of the attack, decay and release stages, the amount and curve of the velocity response, and the trigger type in mono and unison modes. In addition, you can determine whether new contours are initiated from zero or from the current value when you press the next key that uses a given voice, and you can loop contours to create additional cyclic modulators. With the attack and decay set at or near zero, the loop frequency strays into the audio range, which means that your next sci‑fi soundtrack need never be far away.

The two digitally generated LFOs offer three standard waveforms, sample & hold, plus your choice of one from 11 complex shapes to insert into a fifth slot. They can be unipolar or bipolar, synchronised to clock, key‑sync’ed and applied globally or per‑voice. Furthermore, you can determine their ranges individually on a per‑patch basis with a maximum of up to 1kHz, which means that yet more AM and FM effects are...