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Moog DFAM

Percussion Synthesizer
Published June 2018
By Paul Nagle

Moog DFAM

Moog’s Drummer From Another Mother cocks an inventive snook at conventional percussion synthesis.

In the Mother‑32, Moog created a petite and accessible desktop synth with a built-in gravitational pull towards the black hole known as Eurorack. Hoping to earn the same love and popularity, the follow-up is the DFAM, a percussion-focussed analogue synthesizer with a built‑in step sequencer. Once again Moog have fitted a panel of patch points, just in case you haven’t yet been sucked into an alternate dimension.

The Defamation Game

Nobody thinks up wacky product names quite like Moog and, as such, the Drummer From Another Mother really needs no further comment. Fortunately, DFAM rolls nicely off the tongue, so let’s stick with that!

In its quest to supply tweakable electronic drum sounds, this synth somehow crams two VCOs, three envelopes, a classic Moog filter, a step sequencer and that 3x8 patchbay into almost no space at all. Although presented as a neatly angled desktop unit, the DFAM will slot into a Eurorack case (where it occupies 60hp), or into one of Moog’s own Mother rack stands.

The finish is to a high standard throughout and all the regular knobs are pleasingly smooth and set in plenty of space. The switches have a small amount of play in them but the only real suggestion of penny-pinching is found when you reach for the sequencer — its 16 knobless stalks rate as poor in comparison to the other controls. I could just about tolerate this sort of size reduction in the mixer section but it leaves the step sequencer feeling distinctly unfinished, hence I can understand why many owners are fitting their own knobs, slipping them on as Moog should have done.

The DFAM’s back panel is Spartan to say the least, with just a quarter-inch audio output and a socket for the 12V power supply. The DFAM’s back panel is Spartan to say the least, with just a quarter-inch audio output and a socket for the 12V power supply. The rear panel is about as simple as you’ll find anywhere: just a quarter-inch audio output (doubling as a headphone jack) and the connector for the external power supply. If you happen to prefer mounting into a Eurorack case, the DFAM requires 230mA and draws exclusively from the +12V supply.

Drum Synthesis Made Easy

The VCOs produce either triangle or square waves and there’s a convenient white-noise source on hand too. So while the DFAM won’t cover every Moog sound of your dreams, it is well set up for its synth percussion role — and others besides. In the oscillator section we encounter the first of three simple envelopes, each consisting of a single decay knob. Since the pitch modulation amounts are independent for each VCO, and also bipolar, you already have a great starting point for creating analogue kicks, toms, wobbly bass and a whole raft of dinks, plinks and zaps.

The oscillators cover a wide pitch range, with each sporting a 10-octave (!) frequency control. Even this isn’t the full story, because the sequencer and patch panel can push the pitch further, from a starting point set by the Frequency knobs. For reference, it’s worth noting that the central frequency position is equivalent to the mid-point of the sequencer’s pitch knobs.

In one of a handful of built-in modulation routings, VCO2’s frequency may be modulated by VCO1 — to reveal a world of squeaky, metallic and often dirty FM tones. The final oscillator twist is hard sync: flip the switch and VCO2 is locked to the phase of VCO1. Not only is sync a route to a richer palette of base waveforms, it becomes even more interesting when combined with FM. Those poor oscillators don’t quite know where to turn — especially if their starting pitches are far apart — but their tortured screams are our complex sound sources!

I mentioned the small mixer already, and it’s fine for the job of setting the levels of the VCOs and the white noise generator (or external source if connected). Pushing all the levels to the max can give a mild saturation to the filter but occasionally you crave something edgier.

In its 24dB low-pass mode, the filter offers an excess of Moog creamy goodness. High resonance contributes its typical electronic sweetening effect alongside the equally typical bass-lightening, which is where those cravings for a more extreme overdrive arise again. Taken to the highest levels of resonance, the filter breaks into self-oscillation; the resulting pure tone is then available as an additional audio source.

As with the oscillators, the filter has its own decay-type envelope and bipolar amount. None of the bipolar knobs have a physical notch at zero but, strangely enough, I was only bothered by the omission in the filter section. The filter has a second modulation routing set up too — sourced from the white noise generator. When used in this way, noise applies a welcome distortion-like effect to any percussive voice and even a small amount roughens things up nicely. Unlike the adjacent filter envelope knob, noise modulation is not a bipolar control and its zero point is therefore not at 12 o’clock, something that becomes relevant if you substitute another modulation source via the patchbay.

The filter’s high-pass mode has an unusual feel. True, it cuts away lower frequencies, but it’s not a smooth sweep over the whole frequency range. You’d probably hope to achieve super-thin whispering tones by aggressively filtering white noise, but here the results perform more like a basic EQ and the resonance is also rather underwhelming. Still, it’s an extra flavour and a worthwhile alternative to the fuller, fatter low-pass tones.

Moving onto the VCA, it too has an envelope. Combining a short filter envelope blip with a much longer VCA decay is invaluable when building more subtle percussive voices, so Moog are to be congratulated for not skimping here. And with the sequencer running and this decay set to maximum, the DFAM can become a neat source of drones and weird sustained tones — on its days off from percussion. The VCA’s envelope is the only one that includes any variation in its preset attack time: a fast/slow switch changes the usual response from 1ms to 100ms. This is just sufficient to simulate shakers and softer bass sounds.

While it might seem limiting that there isn’t more control over the envelope shape, in practice I never felt restricted, and if you need additional stages, external patching is your friend. Actually, the choice of controls feels carefully optimised throughout for fast and clutter-free operation. Even before you begin to explore the patchbay, you’ll soon learn to slip from one familiar electronic drum sound to the next. Moog supply patch examples plus a handful of cardboard overlays to set you off on your drum synthesis adventure — just like the old days.

The DFAM has the same dimensions (319 x 107 mm) as the Mother-32, meaning that it can be happily racked alongside one in Moog’s optional stand.The DFAM has the same dimensions (319 x 107 mm) as the Mother-32, meaning that it can be happily racked alongside one in Moog’s optional stand.

Sequencer

For some of us, the idea of a step sequencer from Moog is loaded with nostalgia and expectation. Once you get past the slight disappointment of sourcing your own knobs, the prospect of two rows of eight steps seems promising enough. The top row is normalled to pitch while the bottom is routed to velocity — ie. it drives the level of the envelopes. Pitch and dynamics are an effective pairing even before you check out more exotic options with the patchbay. Via a switch in the oscillator section you can decide whether the sequencer controls the pitch of both VCOs, just VCO2, or neither. I mentioned earlier that the sequencer can transpose the oscillators from their starting frequencies, hence you can quickly get into bat‑bothering areas or low-frequency clicks and rumbles when the mood takes you.

Analogue sequencers may not be as complex as their digital counterparts, but their strength is usually in the ease with which they can be manipulated during playback. It’s when you start to examine the options available that you spot a shortcoming or two. Most significantly, the two rows are fixed at eight steps; there’s no way to do that thing most step sequencers delight in, which is dynamically vary the pattern length, or send a ‘reset to step 1’ from an external source. Nor can you run the two rows in series to create a 16-step pattern, which is a deviation from drum machine convention.

The tempo knob is rated at between 10bpm and approximately 10,000bpm, making the DFAM a worthy stand-alone generator of insane noises at its extremes. You can even feed one of the sequencer rows into the tempo CV input to produce crazy stuttering, skipping patterns. Running the sequencer at its top speed gets into audio rates — connect the pitch row to the external audio in and you can process the resulting waveform with the filter.

When the sequencer is not running, you can manually trigger the envelopes with one button; another button advances the sequencer but doesn’t trigger them. If you wish to sync up your DFAM patterns with other gear in the studio, it’s highly likely you already have a favoured master clock source. An external clock received at the ADV/Clock input is all that’s needed to lock the DFAM to this. Once slaved, both the tempo knob and the tempo CV input become redundant. I therefore couldn’t help thinking how cool it would have been if Moog had repurposed these for sequence length control and reset, while an external clock is present.

Regardless of clock source, the sequencer will start running if you hit play or when 5V is present at the run input. Oddly though, this external method of starting the sequencer doesn’t mirror the Run/Stop button exactly because the envelopes aren’t triggered.

Patchbay

The neatly positioned patchbay is useful for more than just clocking the sequencer — it also provides the means to drive the DFAM’s entire synth engine externally. Any connection at the velocity input overrides the sequencer’s second row, which can then be redirected to whatever else you like. Similarly, each VCO has a 1V/Oct pitch input, ready to accept input from external keyboards, sequencers, etc.

This ability to override the normalled routings is what really brings the DFAM to life. Moog include five patch cables and several fun examples to try, but it’s also worth being aware that the patchbay voltages are a bit of a mixed bag. For example, the sequencer’s pitch row is calibrated for a range of -5 to +5 V but the velocity row only sends 0-5V. And while some patch points expect a range of -5 to +5 V, others go from 0 to +5 V, or 0 to +8 V. With no built-in multiples, mixers or attenuverters, external patching is going to reap huge rewards.

Of particular value are the voltage inputs for controlling the decay of each envelope. Drive any of these from a random source or external LFO and you can easily add movement to an otherwise static looping sequence. Another big plus is the ability to vary the noise level and FM amount from an external voltage source — or the onboard sequencer. This level of control enables a humble monophonic drum synth to deliver a great deal of variety.

The external audio input is scaled for Eurorack levels, so you might need to boost any line or instrument level signals for processing by the DFAM’s filter. Sending the whole VCA output back in at this point doesn’t quite mirror the Minimoog overdrive trick, but there’s no reason you can’t amplify it externally first when grit is your aim. I discovered that a looped and transposed sample of a mountain stream (taken from a Make Noise Morphagene) produced a remarkable hi-hat in conjunction with the DFAM’s high-pass filter and with the sequencer varying the VCA envelope decay time.

When you feed anything into the filter’s modulation input, the internal white-noise source is replaced. My mountain stream worked well there too, but I couldn’t resist trying out pink noise (and darker) to summon Minimoog-esque growls and tympani-like booms. Since you have the output of both VCOs available on tap, you can serve up sizzling audio-rate filter modulation too.

The patchbay is a brilliant addition and just a few external modules are enough to completely change the DFAM’s character. One of the first things I tried was feeding the raw VCA output into a Make Noise LxD (Low Pass Gate), using one of the onboard EGs to provide a short decay. This simple patch transformed the DFAM’s output, lending my electronic drums a Buchla-style body and presence.

Conclusion

On paper, the DFAM seems to outgun its predecessor, the Mother‑32, in a couple of areas. Admittedly it lacks MIDI and its patchbay is smaller, but it has two VCOs, oscillator sync and three envelopes (albeit simplified for percussion). With such wide-ranging frequency knobs, it’s not ideal for melodic use, but it can be done. The sequencer, especially in its ‘naked knob’ form, isn’t the ultimate choice for accurate melodic sequencing — but, again, with patience it’s achievable. However, this would be missing the point somewhat because the focus is so clearly on electronic percussion. In this role, perhaps all that Moog have missed from the DFAM’s armoury is a ring modulator, but you can patch one in from your own choice of companion Eurorack modules should the need arise.

The DFAM experience is immediate, enjoyable and above all immersive. Time in the outside world passes at a completely different rate and I often only came up for air to grab a particularly spicy loop into my Elektron Octatrack (before it morphed seamlessly into something else). This is a drum synth from which impressive sounds are easily coaxed; indeed it’s a challenge to serve up naffness. That’s not to say Moog totally nailed it, though. The step sequencer is frustratingly close to being cool, but the omission of a reset input or some other way of shortening patterns is a significant limitation. It is eight steps and always eight steps. Fortunately, you can resort to an external sequencer when necessary and the patchbay is always on hand to carve out more than the basic architecture promises. I therefore suspect Moog will sell a lot of these, especially to anyone who already has a Mother‑32 or who is interested in Eurorack but seeking a gentle introduction.  

Alternatives

You could put together a few percussion modules and an eight-step sequencer in a Eurorack system but you’d struggle to match the price, the friendly ergonomics or the fun factor of the DFAM. A Mother‑32 might be an alternative too, but combining the two would be an even more tempting proposition.

Korg’s Volca Kick and Beats are always credible solutions to sequenced percussion, especially if size and cost are important, but you’d be sacrificing the spacious knobbage and modular interconnectivity of the DFAM.

Finally, no contemplation of alternatives would be complete without mention of the new Behringer synths. At the time of writing, the Neutron is not yet available but the Model D certainly is. A Minimoog at this size and price covers percussion well enough and leaves plenty of scope to add a sequencer or two. The Korg SQ1 would be my first thought for this; a fine example of how to make a powerful but affordable step sequencer in a reduced form factor.

Published June 2018