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Moog Analog Delay

500-series Analogue Mono Delay By Matt Houghton
Published October 2013

Moog Analog Delay

Moog are best known for their synths, but could all their analogue expertise also make for a delicious delay?

Moog's second foray into the 500-series world (their Ladder filter was reviewed in SOS June 2012), is the Analog Delay, and it's exactly what its name suggests: a delay with a fully analogue audio signal path. More precisely, it's a bucket-brigade delay (see the box), based around four NOS Panasonic low-noise, high-voltage bucket-bridge delay ICs, which combine to provide a total of well over 8000 stages in the delay line. The delay line's oscillator/clock may be controlled in a variety of ways, including via MIDI, from an external controller or the bundled DAW plug-in, to create quite complex effects.

Although it's the first 500-series delay I know of, it's not Moog's first delay. They explained to me that "we essentially took what we knew from designing the [Moogerfooger] 104 and 104M delays, and then spent a lot of money on audiophile-quality parts. We also completely redesigned the input and output circuitry, which increases the headroom significantly, lowers the noise, and adds this beautiful body and colour to anything it touches.” They would say that last bit, I know, but it's not mere marketing bluster; this thing really is a joy to use and listen to, as I'll explain.


The module is neatly constructed and pleasingly laid out, in so far as that's possible within the single-width 500-series format. A metal casing protects the circuit boards and components, but you can glimpse the innards via the case's open top and bottom. As with all 500-series units, the analogue audio I/O and power rails are provided by your 500-series chassis, but the front panel also provides MIDI DIN and CV/Tap quarter-inch TRS jack input sockets.

A quick tour of the front panel hints at most of what the module can do when used without the software. The five knobs around which user control is centred are nicely spaced to allow your fingers easy access for tweaking. The top pair cater for drive (input gain) and output level, enabling you to control the basic tone of the signal path, which ranges between clean and nicely, warmly overdriven. Beneath these, the largest knob is used to set the delay time, which can be anywhere between 35ms (the lowest time marked is 80ms, but the lowest position is actually 70ms) and 800ms. A toggle switch governs a delay-time multiplier, whose 0.5x and 1x settings enable you to reach those two delay-time extremes. There's also a feedback control, the legend of which runs from zero to infinity, and finally, a knob which governs the wet/dry balance of effect and source signal.

The knobs and toggle switch are joined by some useful LED indicators, which offer more information than a first glance might suggest. A tri-colour audio signal-level LED uses its colours to indicate different levels: green denotes signal present, orange that the on-board limiters are acting, and red that the circuitry is being driven subtly into saturation. The Time LED is another tri-colour type, the colours in this case telling you whether the delay time is set via the front-panel control, MIDI or the Tap input. The third LED indicates the LFO rate, and the last the presence or otherwise of a MIDI control signal (though not MIDI clock). The relay-driven hard bypass takes both the delay line and the gain controls out of circuit.

In stand-alone mode, the MIDI input can be used to control further parameters with note data, modulation data and so on, and the comprehensive manual lists the MIDI controller numbers for each parameter. The CV/Tap socket is a TRS type, which provides a +5V reference on the ring, input on the tip and ground on the sleeve. Again, MIDI controllers can be used to alter the destination of the CV/Tap input signal.

Plug-in Power

The plug-in offers access to far more parameters than the module's front panel, and enables you to automate settings via your DAW.The plug-in offers access to far more parameters than the module's front panel, and enables you to automate settings via your DAW.

So far, then, this doesn't sound all that different from some other high-end delays, but things become much more remarkable when you start using the accompanying software — there's a stand-alone editor as well as a VST/AU/RTAS plug-in for Mac OS and Windows. With the delay hooked up to your computer via a MIDI interface, the software can, of course, be used to perform simple chores such as editing, storage and tweaking of most settings, the exceptions being the analogue hardware controls for drive, output and wet/dry mix, which can only be adjusted using the front-panel knobs. All parameters can also be automated in your DAW host, as with any conventional plug-in, and there's a 'send' button, to set all parameters on the hardware to reflect those on the software — which is useful for saving and recalling presets when you're not using automation. The physical controls aren't motorised, so don't move to reflect changes of setting performed within the plug-in. (Not that I'd expect them to, but it's worth mentioning this for the sake of clarity.)

The greatest benefit of using the software, though, is that it allows the user access to far more parameters and settings than would otherwise be possible via the diminutive 500-series front panel, and it's far more intuitive than doing so using an external MIDI device. For example, the plug-in offers you a selection of various LFO wave shapes, plus control over the LFO rate and the degree to which this modulates the delay line. There's also tempo sync, much more detailed control over the delay time and modulation settings, and even a delay slew-rate knob, which governs the speed of transition from one delay time to another, as well as drop-down menus to select the behaviour of the CV/Tap input.

In Use

I ran a number of different sources (including guitars, bass and lead synths, acoustic and electronic drums and vocals) through the Analog Delay, having first set it up as a hardware send effect within my Cubase 7 64-bit DAW. Initial experiments playing a virtual synth with one hand while tweaking the delay with the other provided immediately gratifying results. Without any delay engaged (the Moog set to 100 percent dry, and with the source channel's output muted in the DAW), juggling the drive and output levels allowed me to coax a beautiful, warm-sounding overdrive from the Analog Delay. I found that I had plenty of control over the degree to which that character was applied, too. This pleasing tonal coloration is one of the main things that differentiates this delay from others I've used.

Reinstating the synth's direct output and tweaking the delay time and feedback knobs revealed just how useful this sort of sonic character is in a delay. When used as a conventional delay effect, with relatively obvious delay-time and feedback settings, the sound was always neatly tucked in somewhere 'behind' the source, in the way that bucket-brigade delays do so well. The result is an effortless sense of ambience which just never gets in the way of the main source sound, the latter remaining very much the star of the show. Of course, it's perfectly possible to completely bury the source sound if you prefer, using the wet/dry blend control and placing this device in series with your source. Playing with the feedback and blend controls allowed me to drown the source in a marvellously pulsating ambient wash, and with the feedback set to infinity, that wash was sustained indefinitely. In fact, when I did this, the thing kept feeding back even when I shortened the delay time and backed off the hardware feedback control completely!

With very short delay-time and feedback settings, it was also possible to create a lovely chorus-like effect — and while I only had one unit on test, I'm sure that a pair of these could create a stunningly good stereo chorus. I was also pleased to discover that there was very little by way of clicking or popping when I flipped the delay multiplier toggle switch, which means that this could also be used in real time as an effect.

This being a bucket-brigade design, the delay time and pitch are inextricably linked, and this can make for great fun if you change the delay time while the sound is playing — something that's not a million miles away from speeding up and down a tape delay, but with its own character. The same is true when you flip the multiplier switch, but the effect is less immediately noticeable, simply because the pitch change is a full octave. Speaking of the multiplier, this does not just alter the delay time, but also the tonality, with the 0.5x option sounding noticeably brighter (though still warm and cuddly!) than 1x, even when the unit is operating with the same delay time.

Rocking The Mods

Whatever modulation settings were already set on the review unit allowed me to create some engagingly thick and complex textures when using liberal amounts of feedback, and generated a useful sense of space and subtle movement with more moderate feedback. Unfortunately, there's no control over the LFO settings when the Analog Delay is used as a stand-alone unit, other than via an expression pedal or external MIDI device, in which case you really need to have a MIDI CC reference chart handy! This is where the software comes into play...

Hooking my audio interface up to the Analogue Delay via a MIDI cable, and selecting the appropriate MIDI Out channel on the plug-in GUI, brought access to a plethora of control options. For starters, there are eight separate LFO waveforms to choose from: flat (ie. off), sine, triangle, regular square, two sawtooths (one running in each direction), and two sample & hold waveforms, one with angular corners and the other more rounded. What I found most useful in practice was the LFO Amount setting, which allows you to make whatever modulation you've applied sound more subtle or obvious as you prefer.

If I'm honest, that would have been quite enough control for me, but the plug-in offers far more. So much, in fact, that it should satisfy all but the most demanding tweaker. For instance, there are options that enable you to govern how the pitch wheel affects the delay time, to set the delay time via a MIDI note, to tweak the LFO amount via the Mod wheel, and use MIDI note control to reset the LFO.

I experienced one mild annoyance with the plug-in when using it within the 64-bit version of Cubase 7, which was that when I used the drop-down menus, the plug-in's GUI went blank. This didn't stop the delay functioning at all, but to get the GUI to reappear, I had to close or minimise and restore the plug-in instance. This didn't seem to be a problem with other DAWs, or in Cubase 7 32-bit. I tested this plug-in on a Windows machine, but Moog tell me that the AU plug-in is a combined 32 and 64-bit installer, which means it should work with Logic Pro X (which no longer supports 32-bit plug-ins). At the time of writing, the lack of support for the AAX plug-in format means that it will not work with Pro Tools 11, though Moog tell me an AAX version is imminent. Meanwhile, there's always the stand-alone editor and conventional MIDI control.


This is a remarkably versatile and powerful analogue delay that integrates well with modern DAW software. It sounds sublime, both in terms of the overall tone and the delay effects that can be created. I hope you'll pardon the cliché, because this really would be my desert-island delay. I'm glad that's the case, because at this price it really needs to be — particularly if you plan to link two modules for stereo effects. It's a good job it stands head and shoulders above any competition!


The world is not short of bucket-brigade delays — many, including the MXR Carbon Copy, in guitar stomp-box format. Some digital pedals mimic this effect pretty well, Strymon's Brigadier being a good example. Moog's MoogerFooger MF104M is an obvious contender, and modular-synth enthusiasts might be interested in Doepfer's offerings. Yet none of the above do quite the same thing, few offer the same degree of control or the quality of signal path, and none a dedicated plug-in.

The Bucket-brigade Design

The beating heart of the Analog Delay: four NOS Panasonic bucket-brigade delay ICs.The beating heart of the Analog Delay: four NOS Panasonic bucket-brigade delay ICs.The so called 'bucket-brigade' delay was the first delay design to feature no moving parts. In essence, it comprises a bunch of capacitors in series, each holding up the signal and releasing it to the next in line (hence the term 'delay line'). Although analogue, it is still a sampling system and thus subject to the Nyquist-Shannon theorem. This means that anti-aliasing and reconstruction filters are needed, and these limit the audio bandwidth, contributing to the 'warm' tonality. One thing that makes the bucket-brigade design stand apart from other analogue or mechanical delays is that the timing of each line is governed by a clock signal, the frequency of which can be governed digitally.


  • Sounds utterly gorgeous.
  • Can be pressed into service as a simple delay, but offers so much more.
  • Delay-time multipliers.
  • Lots of control via the hardware, and much, much more control via the plug-in.
  • CV/Tap-tempo input.


  • Not cheap, particularly if you prefer your delays in stereo!
  • No AAX version of the plug-in.
  • Plug-in GUI refresh problems during tests.


This is one of only a couple of 500-series products I know of that can be controlled via a plug-in, which makes DAW integration a piece of cake. Robert Moog may no longer be with us, but this is everything you'd expect of his legendary name in terms of build quality and sonic mojo.


£799 including VAT.

Source Distribution +44 (0)20 8962 5080.


Moog Music +1 828 251 0090.

Test Spec

Windows 7 Ultimate 64-bit PC running Cubase 7, Pro Tools HD10 and Reaper 4.5. Asus P6t Deluxe v2 motherboard with 12GB DDR3 RAM and Intel Core i7 965 processor.