Eurorack and Ruin: Building a Modular Synthesiser

I apologise for the lateness of this post. I originally wrote it in the style of a 1970s New Wave science fiction novel, but following complaints from King Features Syndicate and the Catholic Church I had to rewrite large chunks and eventually there was no point.

But it was awesome! The story culminated with a Marxist revolutionary modelled on Pam Grier forcing Buck Rogers a character that resembled Buck Rogers to sodomise God to death so that He would ejaculate the stars and planets etc.

The ultimate point was that we are the abandoned children of a dead God, which is pretty darn deep if you think about it.

But let's talk about modular synthesisers instead. We can talk about New Wave science fiction another time. Let's talk about modular synthesisers. Specifically eurorack.

What is eurorack? It's a set of physical and electrical standards devised in the late 1990s by Doepfer Musikelektronik GmbH of Germany, based on 1980s computer expansion boards. Before eurorack there was no universal standard for modular synthesisers. US-based systems from Moog, Buchla, Serge and so forth were incompatible with each other.

Eurorack took off because it was compact and relatively simple. Now there are several hundred eurorack manufacturers scattered across the globe. Objectively the eurorack market is tiny, but my guess is that there are far more modular synths in the world today than there were in the 1970s, when politically-aware New Wave sci-fi was all the rage. The New Wave was politically-aware, often juvenile, maddeningly erratic, occasionally brilliant, all too often as cliched as the Golden Age sci-fi it pushed aside.

It's pronounced Doop-fer by the way. The name comes from Dieter Doepfer, after whom the company is named. The OE is pronounced "ooh", which is the noise that God made when Buck Rogers penetrated him. The thing about New Wave sci-fi was that the writers were mostly middle-aged white men who were steeped in the prejudices of white mainstream America, so although the genre was ostensibly progressive their vision of liberal enlightenment involved white heroes taking lots of drugs, using the N-word frequently, and having orgies with sexually liberated women who were background extras in the main character's epic life. Non-white people were noble savages and the idea of women having agency was perhaps too transgressive for the 1970s.

We are trapped in invisible cages. We sing songs of revolution in the language of our oppressors; we don't see the bars. Think of all the psychedelic freak-out records of the progressive rock era that were praised to the skies when they were new, but sound like dated jazzy blues-rock now, because the artists involved - and the critics that supported them - were so immersed in jazz and blues-rock that they didn't realise they were making jazzy blues-rock.

We are trapped. And yet as a child I felt that the nihilism of cyberpunk and the thematic emptiness of 1980s space opera revival and mass-market fantasy was unsatisfying, and for all its faults the New Wave of the 1960s and 1970s had at least tried to innovate, but eurorack. Let's talk about eurorack. Big hit of cocaine and eurorack. Here are some beats made with a eurorack synthesiser while you read about eurorack. I'm not going to talk about New Wave science fiction any more. Not going to talk about it.

Ashley Pomeroy · Modular Disco

Keep away from it. Keep away from sci-fi. Eurorack emerged at a point in time when analogue synthesisers were dead and buried. The analogue polysynths of the early 1980s had been swept aside by sample-based workstations such as the Korg M1 and its heirs, and indeed by samplers; tonnes of musicians in the 1990s ignored synthesisers entirely and bought a sampler instead. For good reason. You could do anything with a sampler. They are incredibly versatile instruments.

Back in the 1990s the analogue scene consisted of clones of the Roland TB-303 bass synthesiser and a few legacy modular systems that were staggeringly expensive and esoteric. The TB-303 clones - the original Novation Bass Station, the Control Synthesis Deep Bass Nine, Doepfer's own MS-404 among others - were analogue to varying degrees, but they were specialised tools intended for one role only. They weren't intended to bring analogue back for the masses.

As far as Roland and Korg and Alesis were concerned analogue was the past. The future of electronic music in the 2000s would involve ISDN and ADAT and sample-based digital workstations and Pro Tools and hard disk recording and a hypothetical replacement for MIDI, and in a way they were perfectly correct, because virtual synthesis became massive in the early 2000s and sample libraries are still with us today.

Virtually all modern television music and a large proportion of film scores are performed with sample libraries of orchestras. Thanks to virtual instruments millions of people have access to a recording studio in their laptop that would have cost a fortune as recently as the late 1990s. But there comes a point when flicking through realistic strings presets gets boring. What if you want bleeps, and bloops? Rhythmic bleeps? And knobs that you can twist with your hands, instead of having to assign functions to a control surface?

An example of good modern music that (probably) wasn't recorded with a modular synthesiser. I include this because I want to stress that I'm not a snob; the only thing that matters is how it sounds.

But analogue was just too cool to die. Hip kids wanted analogue synths because some of their favourite records were made with them, from Oxygene and Computer World to Selected Ambient Works and Felt Mountain and Second Toughest in the Infants etc. Made with them or at least with convincing samples of them. Those kids grew up into middle-aged men with a disposable income, and the cost of manufacturing electronic gadgets with knobs and sliders declined, and people are nowadays willing to spend a lot of money on toys. With the world devastated by a viral plague there's nothing else to spend money on if you have it.

There are also good practical reasons for the analogue resurgence. The abstract nature of simple waveforms is timeless; the simplicity and directness of the classic subtractive synthesis model is refreshing; analogue synthesisers tend to have masses of controls, with instant feedback, and they're all right there in front of you instead of being hidden away behind menus; analogue oscillators don't suffer from aliasing.

And they look awesome. In the 1990s no-one could have imagined that CV/Gate would make a comeback, or that it would be relevant in the year 2021. And yet it did. It outlasted Yamaha's mLAN and the University of California's ZIPI; it is the Morse code of musical instrument interfaces.

My first two modules.

What is CV/Gate? Back in the 1970s analogue synthesisers communicated with each other using a mixture of control voltages and gates. Control voltages carried note information, typically using a standard whereby an increase of one volt represented an increase of one octave. Gates were simple on/off signals that were typically used to activate envelopes. There were also triggers and clock pulses, which were simple click noises, and some manufactures had proprietary interfaces, but let's concentrate on CV/Gate. Let's not talk about New Wave sci-fi any more.

CV/Gate became unwieldy when polyphonic synthesisers took off in the late 1970s - each note required a separate CV/Gate channel - so within a few years the world's musical instrument manufacturers ganged together and devised MIDI, a digital protocol that used a 32kbps serial network travelling down stubbly little cables to transmit note information.

MIDI does the job well enough and it's cheap to implement so it still exists today. It supports sixteen channels of polyphonic note data plus clock plus song pointers, albeit that because it's a serial protocol there are microscopic timing issues, which are further exacerbated by USB-MIDI interfaces.

In contrast CV/Gate transmits data at the speed of light, and furthermore because the signals are simple voltages and the connectors are all the same there's nothing to stop you from plugging a CV output into the control input of a filter, for example, or an envelope generator, or an LFO etc. It's a flexible system that encourages experimentation.

At top a work-in-progress, at bottom the final result (so far).

Modular synthesis has a reputation for appealing to tinkerers, and there's a wealth-signalling aspect as well because it's not cheap. The leading practitioners are drawn from the same pool of thin white men and women that make up the roster of Mille Plateaux records; people who wear their lack of incentive to achieve as a badge of honour. None of them like to talk about where their parents' money came from because their parents are hedge fund managers or lawyers or the chief finance officer of Siemens etc.

Eurorack is a bit of a mongrel dog in that respect because it's relatively simple and affordable. Owners of Serge, Buchla, and Moog systems look down at eurorack. "How cute", they say. There's a class system within the world of eurorack, just as there is a class system in the world of backdated Porsche 911s and vintage guitars and everything. If your eurorack is stuffed with modules from Intellijel of Canada or Cwejman of Sweden you will be respected; if you have modules from Behringer or a no-name brand from eBay you're no fun.

I've always associated Buchla synthesisers with the kind of wealthy Californian who owns a house next to a public beach, and has built a wall to block the public from using the beach, and has spent the last decade appealing against legal demands from the local council to have the wall taken down. This person never visits the beach, he just wants to block other people from using it. On the surface they are lovey-dovey supporters of the arts community, but scratch the skin and they are vipers.

I'm digressing here. What if I am the ranting maniac? No, let's move on. I'm not going to pretend to explain the basics of synthesis or talk about New Wave sci-fi any more. My suggestion is that you get hold of Arturia's ARP 2600V, which models the patchable-but-not-quite modular ARP 2600, and tinker with that for a while. For a shade under £600 Behringer makes a recreation of the ARP 2600 that is extensively patchable. For a similar sum Moog makes the Mother-32, which is simpler but has a lovely Moog filter.

The power connectors are keyed, but it's a good idea to make sure that the +12 and -12 pins line up with the appropriate sockets on the module. Doepfer power buses carry CV and gate signals, but only a handful of modules - all made by Doepfer - can use those signals.

Oh, I'll have a go. Modular synthesis is a bit like Lego or assembly language, in the sense that the individual building blocks are simple but the arrangement of blocks can become complex. A modular synthesiser typically has:

- One or more sound sources. Analogue synthesisers of the 1960s and 1970s used VOLTAGE CONTROLLED OSCILLATORS (VCOs), which generated simple waveforms such as sawtooth, square, and sine waves. In the 1980s digital synthesis with frequency modulation displaced analogue oscillators, and in the 1980s and 1990s digital sample players displaced FM, although while this was happening modular was dead as a doornail, so the digital revolution largely bypassed the modular world. Modular synthesis is extremely flexible, and there is no reason why a modular synthesiser cannot dispense with oscillators entirely and use a shortwave radio as a sound source, or a microphone, or the amplified sound of stones.

- The VCO feeds into a VOLTAGE CONTROLLED FILTER (VCF), which adds sonic colour to the sound by muffling it (if it's a low-pass filter) or brightening it (if it's a high-pass filter) or making it sound like a 1940s radio (if it's a band-pass filter) or making it sound like a throat (if it's a formant filter) etc.

- The VCF feeds into a VOLTAGE CONTROLLED AMPLIFIER (VCA), that shapes the volume of the sound. Why VCO-VCF-VCA, and not for example VCO-VCA-VCF? Because some filters can make sounds of their own, and if there isn't a VCA at the end of the chain the VCF would never shut up.

- This arrangement by itself would produce electric-organ-style BOOOOOOO noises. One of the things that separates a synthesiser from other electronic musical instruments is modulation; in the classic synthesiser model the the VCF and VCO are controlled by a mixture of one-shot ENVELOPES and repeating LOW FREQUENCY OSCILLATORS (LFOs) that make the sound go whooo or ping or bouncy-bouncy or wubble or bah weep gragna weep ni ni bong or zang-zang-tuuumb with three "u"s.

Shown here with a pair of Arturia Beatsteps. The Beatstep has a combination of MIDI and separate CV and gate outputs, and in this image I'm using the gate from the top Beatstep to control the filter, and the lower Beatstep to control the pitch.

There are also slew generators and frequency dividers and phase locked loops, but they are deeper magic for another time. The simple building blocks above can be combined to produce complex sounds. For example you could feed a short envelope into a VCA that's set up to modulate a VCO, thus producing a little pitch jump at the beginning of each note (as in Vangelis' "Chung Kuo" or the classic shakuhachi-type sound), or you could use an LFO to drive another LFO, thus producing a complex polyrhythmic modulation. That's what I'm doing in this video, I'm modulating an LFO with another LFO:

One element that tends to trip people up - it tripped me up - is gates. With a MIDI synthesiser the keyboard automatically routes NOTE ON and NOTE OFF messages to the envelopes every time you press a key, but with a modular synthesiser you have to manually wire the envelope gates up to the sequencer, perhaps using a MULTIPLE to transmit a single gate to several envelopes.

Modular synthesisers are appealing for their versatility. If you want a Minimoog-writ-large that has six oscillators instead of three you just need to find sufficient space to fit the oscillators, plus a mixer to combine them; alternatively if you want to emulate the classic ratcheting "Berlin school" sequencer sound you can fill your case with clock dividers and trigger-gate converters.

Have you ever read about the EMS VCS3? It's a compact not-quite-modular synthesiser from the late 1960s that fetches five-figure sums on the used market, but with a set of eurorack modules you can duplicate most of its functionality for a fraction of that price. Doepfer even makes an affordable spring reverb. By swapping in different filters it's possible to mimic the classic semi-modulars of the past for less money than an actual vintage unit.

The need to wire up new patches puts some people off, but just because every module has a bunch of modulation options you don't have to use them. I recorded the following little ditty just to see if I could make a plain vanilla patch with Plaits. The tune is essentially a duet between Plaits and a Korg ARP Odyssey, with the Model D on bass:

Let's talk about my modular synth and perhaps some of it might sink in. It's built into a Doepfer LC6 case, which has a pair of 84HP racks. HP stands for horizontal pitch; 84hp is a popular width because it can easily be adapted to fit into a standard 19" studio rackmount. Doepfer makes one-storey, three-storey, multi-storey cases in a variety of widths, and there are alternatives from other manufacturers; the case is essentially just a wooden box with a power supply and some rails.

Another popular form factor is the boat, or skiff:

Technically this is the case for my Behringer Model D. Nonetheless it's a standard eurorack size and could be used to house 70hp's worth of eurorack modules, although unless they were all passive I would need to buy a power supply because the Model D's PSU isn't eurorack compatible.

The LC6 comes as standard with a 75w power supply. The power draw of my system is 13.8w, so my hunch is that I would have to try very hard indeed to overwhelm the PSU. The LC6 case is unpainted and unfinished, so I gave mine a coat of Wickes 310 Magnolia, and then a year later took everything out and painted it lemon-lime orange.

Let's have a look at the top row:

Stand by to launch remote control attack ship

On the left is an Doepfer A-118 noise generator, which produces hissy noise and random voltages. It's useful for randomly modulating things or producing percussive noises. I have the impression that a lot of people buy a noise module because they feel that their system needs one, and then never use it. I rarely use mine.

To the right is a Behringer 140, which has a pair of envelopes and an LFO. It's good value at around a hundred pounds. It's designed to mimic the look of the 1970s Roland System 100M. In this image envelope 2 is modulating the A-101 filter and envelope 1 is modulating a VCA that's off the edge of the image. They're both drawing gate inputs from a passive multiplier, although I've unplugged the multiplier's gate source because the holes reminded me of New Wave science fiction.

To the right again is a Doepfer A-101-2 low pass gate. Doepfer makes a range of filters, and I wanted to pick one that was slightly unusual. The A-101-2 is a multifunctional VCF, VCA, and low pass gate -  essentially a VCA that reduces the cutoff frequency at lower amplitudes. Low pass gates are a cheap way of adding colour to a sound, and furthermore some designs don't require power. This particular model has a relatively soft sound, not as thunky as a Moog filter.

To the right of that is a multiplier. Anything plugged into the top socket is routed to the five sockets beneath it. Multipliers are useful for sending the same control voltage to multiple oscillators, or for duplicating gate signals. They generally don't require power.

Moving along is a simple VCA, which doesn't have anything plugged into it. I could in theory send an audio signal to the IN socket, and the output of one of the Behringer 140's envelopes to the CV socket, and the output from the OUT socket would have the original sound with the volume modulated by the 140's envelope.

To the right of that is Mutable Instruments' Plaits, which is a grab-bag of digital synthesis models. It appealed to me because I already have an analogue synthesiser, so there must be other songs to sing. Plaits' range of models includes a virtual sawtooth/square, simple FM and wavetable synthesis, plus a granular supersaw and some drums. At first I was disappointed with it, but after plugging in a bunch of modulation sources (pictured) it came alive. Plaits also has a built-in envelope and low pass gate, so you can use it entirely by itself if you just plug a CV source into the CV input and a gate source into the trigger input.

To the right is a wooden blanking plate, and to the right of that is a TAKAAB 3LFO, which is made by Siam Modular of Thailand. The module's LFOs aren't synchronised with anything, so they're relatively limited - they just run of their own accord - but the unit costs around £46, which is good value for three LFOs. The LFOs run at different rates, with the top fastest and the bottom slowest.

To the right again is a Doepfer A-130 VCA, which is boring but has a separate gain control, so it doesn't require a control voltage to pass a signal. Eurorack is unusual in that Doepfer's first-party modules are generally no more expensive than their third-party equivalents, which is why my system has such a diversity of modules. In terms of online cachet Doepfer has a reputation for being functional but boring.

Just peeking into the frame on the right is a Doepfer A-166 dual logic module. Imagine two sequences of ones and zeroes that run at the same rate. If the two sequences have a 1 at the same time an AND gate will output 1 (1 AND 1 is 1), and an OR gate will also output 1 (1 OR 1 is 1), but an EXCLUSIVE OR (XOR) gate will output 0 (1 BUT NOT 1 is 0).

Did that make sense? I worked it out by plugging things into it and noting the end result. If you plug a bunch of gates or triggers that run at different rates and at different times into the inputs, the outputs will be a selected mixture of all the inputs. The end result is an unpredictable but repeatable sequence of gates that can be mixed with a regular gate to produce interesting rhythmic results.

In this video I've moved the logic module to the top-left of my rack. I'm feeding two gates and a high-speed trigger into the logic module, which doesn't quite work because the trigger isn't active long enough to have much impact on the logic. Nonetheless you can hear how the bassline has a distinctive trilling sound, as if a woodpecker was drilling into the keys.

I modified my system during the course of this blog post. At the extreme top-right I now have a Mutable Instruments Yarns, which is a MIDI-CV converter. It can be set to convert four channels of MIDI input into four separate CV/Gate combinations, or alternatively one channel of MIDI into CV/Gate, Velocity, Modulation, and aftertouch (or two channels of MIDI with CV/Gate and velocity). It also has a step sequencer and a surprisingly complex arpeggiator that can be applied to each channel separately.

Let's look at the bottom row:

The vast bulk of the bottom row is taken up with a Behringer Model D, which is a clone of the Moog Minimoog. It's a three-oscillator monosynth with a wicked filter. It comes in a wooden case:

But as you can see it can easily be removed and added to a eurorack system, in which case it uses the rack's power supply. It has a range of patchable inputs and outputs, but it's not truly modular. There's no way to address the individual oscillators and it doesn't transmit CV, which is unfortunate because it would have been a useful MIDI-CV converter if it did. My rack feels a little bit like a pair of independent synthesisers that happen to share a case.

To the right of the Model D is a simple passive attenuator, which reduces the strength of signals. This is useful if your LFO is too strong. To the right of that is a three-channel mixer, which in the above image is taking both of the outputs from Plaits. Some mixers can be controlled with voltages; this mixer has knobs, only knobs, human-controlled knobs, for a human.

But Have You Considered the Cost?

My suggestion is that you budget a thousand pounds. Aim to spend seven hundred pounds, but accept that you'll actually spend a thousand pounds. Doepfer makes a prebuilt system called the A-100 for £1,800, but it strikes me as an esoteric choice for a beginner because a lot of the modules are very specialised and yet it only has two proper VCOs.

I chose a two-storey case because I wanted to eurorack my Behringer Model D and have a row free for extra modules, but you might want to start with a one-storey case instead. Let's imagine you want a simple analogue synthesiser with some modulation options. You're willing to leave complex sequencing modulation with mathematical operations until you've learned a bit about modular first.

I'll pick prices from London Modular mainly, but there are other shops on the internet (Amazon sells Behringer modules; Thomann in Germany is popular on the continent but bear in mind the prices don't include VAT).

You might choose:

- A Doepfer LC3 84hp one-storey case for £185

- A Doepfer A-111-6 Miniature Synthesiser Voice (10HP, £150)

- An ALM MMMidi MIDI interface (6hp, £90)

- A Behringer 140 dual envelope / single LFO (16hp, £95)

The A-111-6 is a little mini synthesiser with a VCO, VCA, and VCF. It's usable by itself, but without proper envelopes and an LFO the end result is very simple. This setup by itself costs £520 and will at least make noises - it's not a million miles from a Roland SH-101 - but it would be very basic. An Arturia Microbrute is half the price and more flexible, albeit at this point you still have 52 units of space left.

Alternatively you could drop the Doepfer A-111-6 - it feels like cheating - and replace it with a Behringer 112 Dual VCO (16hp, £95) and a Doepfer A-121-3 VCF (4hp, £95) which would come to £560. Alternatively you could do what I did and use Mutable Instruments' Plaits (12hp, £195) as your sound source. One downside of this is that everyone has Plaits, because it's ace, so although people on the internet might not mock you they will not respect you either.

You might want to expand your basic system with:

- A Meng QI Split Multiple/Attenuator (4hp, £55)

- An ALM MCO Digital Oscillator (6hp, £135) for some sonic variation; it would plug into the A-111-6's external input in lieu of a mixer

- A Doepfer A-124 Wasp Filter (8hp, £77)

- A TAKAAB 3LFO from eBay (4hp, £46)

This costs an extra £313 and leaves you with 30hp. At this point however you have two fundamentally different oscillators, two filters, four LFOs (one triggerable, three not), two ADSR envelopes, a MIDI interface and a multiple to split the gates. Alternatively ditch the filter and oscillator and buy a MakeNoise Maths (10hp, £275), and perhaps replace the MIDI interface in the first block of modules with a second-hand Mutable Instruments Yarns, which gives you four channels of CVs and Gates to feed into Maths.

The issue of space is a thorny one; if you start with a one-storey case every extra storey you add will cost £185, when you could have spent an extra £100 and bought a two-storey case to start with. On the other hand if you get bored with a one-storey case and decide that modular synthesis is a waste of time you've saved yourself that extra £100.

Of course you have to ask yourself if you really need a modular synth. They're great fun to play with, but they cost a lot of money and even in eurorack form they're awkward to transport and gig with. The professional musicians who used modular synthesisers in the early 1970s - Keith Emerson, Tangerine Dream and the like - generally abandoned them as the decade moved on, because smaller, more portable keyboard synthesisers and semi-modulars replace most of their functionality.

Many of the classic albums I grew up with - Chill Out, Endtroducing....., Lifeforms, Logical Progression, U F Orb - didn't even use synthesisers at all, they were based entirely around sequenced samples. And for the same money as the setup above a Behringer 2600 and an Arturia Minibrute could duplicate a lot of its functionality. With the suggested builds above I didn't consider the cost of patch cables and I have assumed you already have an audio interface and a computer.

On a personal level I was inspired to build a eurorack system by the existence of the Moog Subharmonicon, which combines an oscillator with a four-step sequencer; it's an appealing thing, but at £800 it's far too expensive for what it is. For the same money I could build a more complex synthesiser, so I did.

Such is the pace of change in the modern age that I bought a spring reverb even before it appears in the main body of the article. Isn't that reminiscent of the non-linear narrative of Kurt Vonnegut's classic New Wave sci-fi novel Slaughterhouse-Five?

More than anything however I was inspired by the fact that Doepfer makes a spring reverb. The A-199. It's only £80 on the used market. I don't have it yet, but one day I will. Both All of the classic semi-modulars of the 1970s had a spring reverb. A spring reverb is a bunch of springs in a metal box with a microphone that sounds like the 1950s. I can't think of a better reason to build a modular system. The chance to own a spring reverb, and for it to mean something and actually have a use.

Corona Variations II/III

Life is a relay race. Every generation passes the baton to its children in the hope that they might reach the end, but there is no end; one day the last human being will fall, and many years later the track will be empty, save for a lone baton resting on a thin layer of dust. The only victor in the relay race is the baton.

The only victor is the baton. That is your first codephrase. The only victor is the baton. A few years ago I bought an old Apple Power Mac G5. A 2.0ghz dual-processor model from 2003. An infernal engine that generates answers by blowing air into a furnace of electricity. It has a slightly bent foot, because the case weighs almost twenty kilograms and aluminium doesn't bend back.

Aluminium doesn't bend back. That is your second codephrase. Now that the world has ground to a halt I decided to fire it up and record some music with it:. Two tracks, one live, and one not:

My G5 came with a Mark of the Unicorn PCI-424 interface card, and shortly after buying it I picked up a contemporary MOTU 2408 Mk3 audio interface for a fraction of its original price. Here it is:

The 2408 is essentially a posh sound card with a bunch of audio inputs and outputs. The idea is that you can plug several instruments into the inputs and record them all at once, or alternatively you can send audio to several outputs, for example if you have a bank of speakers in a concert hall and you want them all to play slightly different sounds. The ADAT and TDIF digital tape interfaces aren't much use in 2020, but it has eight balanced mono quarter-inch jack plugs, which are timeless.

It connects to the MOTU PCI-424 card with "audiowire", which is what Mark of the Unicorn called FireWire 400. I use a standard FireWire cable. The digital i/o was probably very useful in 2003, less so now that most outboard digital gear has been virtualised. I have to admit that SMPTE synchronisation is beyond me.

Eight balanced 1/4" inputs and outputs, which can be used as four stereo pairs. The 2408 is full-duplex, e.g. it'll play back and record simultaneously.

Sound on Sound magazine reviewed the 2408 back in 2003, presumably plugged into a Power Mac G4. The 2408 was part of a system that included the MOTU 24I/O, which had 24 analogue inputs and outputs, and the MOTU HD192, which was similar but with XLR jacks. Presumably the HD192 was aimed at concert PAs who needed to mix lots of microphones. Seventeen years later the 24I/O is the most useful of the three units on the used market, but the 2408 seems to have sold in greater numbers, or at least there are more available second-hand. NB there were Mk1 and Mk2 versions of the 2408, which were similar but used RCA jacks instead of quarter-inch plugs. I'm not sure why.

The modern equivalent of the 2408 is the MOTU 828, which connects directly to laptops and desktop machines with a Thunderbolt cable; for historical reasons the 2408 connected to a special PCI card inside the computer, although the actual cables were standard FireWire. The PCI-424 card has four inputs, so you can connect several interfaces to it, and surprisingly it works with Windows 10 because MOTU still supports the card.

What is an audio interface? Imagine a mixer that doesn't mix. The idea is that you use your sequencer or digital audio workstation as a mixer and effects unit, perhaps with a USB control surface to manipulate the sliders. Here's what the second song above looks like in Logic Express 9 running on a Power Mac G5:

Three tracks of instruments and two tracks of drums, separated by some spurious MIDI data. The blippy, swirling sequences that run through the song are tracks 1-3, which were made with a Behringer Model D, sequenced with a 16-step Arturia BeatStep step sequencer. Tracks 4-5 are nonsense that I used mostly to keep the Model D in tune. Track 6 is a software instrument running on the G5; it's the swoopy solo noise. Tracks 7-8 are respectively a Korg Volca Sample and a Korg Volca Beats drum machine.

If you record music one track at a time the multiple inputs of an audio interface are overkill, although they tend to have better sound quality and perhaps even lower latency than the soundcard built into your PC's motherboard. The 2408's balanced inputs have the benefit of eliminating ground hum, which is a problem that VST/AU software musicians don't have to worry about until they start using physical instruments, at which point it becomes infuriating.

If you want to record several instruments at once you could in theory use a mixer; the advantage of a multichannel audio interface is that you end up with multiple channels of audio that you can mix and remix later on, whereas with a mixer you end up with a processed stereo pair that you can't tweak any further.

Clockwise from top, a Behringer Model D, a Volca Beats, and a Volca Sample. Coronavirus aside, we're living in a golden age of reasonably-priced synthesiser technology.

Korg's Volca instruments were launched in 2013. The first wave consisted of the Volca Beats - a hybrid digital / analogue drum machine - plus the Volca Keys and Volca Bass, which produced synth tones and basslines respectively. They sold well, and the range has since expanded to include a sample-playback drum machine (the Volca Sample, pictured above), as well as a mixer, and even a tiny modular synthesiser that uses patch cables to build sounds.

Conceptually they mimic Roland's early-80s TR/SH/TB-X0X range, but with enough embellishments and at such a low price that they feel like a homage rather than a copy. They all have MIDI IN and rudimentary built-in sequencers, plus analogue clock sync, which has led to a fascinating revival of CV/Gate and analogue sequencing. Remember, the only victor is the baton. You will know what to do.

They have some limitations. They're physically creaky, and the two I own have noticeable background hiss. It's not offensive and you can gate it out, but it doesn't sit well with amplification or compression. They use unbalanced 3.5" stereo jack plugs that feel flimsy, and the lack of USB is irritating in the case of the Volca Sample; you have to upload samples with an audio cable, which is akin to loading 8-bit video games from tape. The Volca Sample's sequencer can chain patterns together but the Beats can't, and none of the Volcas have MIDI OUT, so you can't use them to drive other instruments. Unless you modify them, and some people do, but they use teeny-tiny surface mount components that require a deft soldering hand.

They run from six AA batteries or a mains power supply (not supplied). As with the Model D they're really too limited to build a career on - an extremely creative musician might get an album from them, but as with DJ Shadow the basic sound would become monotonous - but as a cheap way of adding analogue or digital colour to an otherwise computer-only setup they're great fun; the step sequencers in particular are a fun way of generating simple ideas. Perhaps best of all they tend to hold their resale value, so if you get bored with one you can sell it on again.

Imagine if there was a way to convert money into objects, and then back into money. You'd revolutionise world trade. Imagine it.

Using the Behringer Model D as a Filter

A while back I had a look at the Behringer Model D. It's a modern-day analogue synthesiser that emulates the venerable Moog MiniMoog. I've never used a MiniMoog, so I can't compare them myself, but the internet believes that the Model D is the musical spitting image of the original and so does this chap from Sound on Sound magazine. As an instrument in its own right I enjoy it immensely although it's not as flexible a synthesiser as the Korg ARP Odyssey (for example).

Physically it feels cheap but original MiniMoogs are now so expensive on the used market that they're almost unusable in a live context. What if you spill beer on your MiniMoog? What if it gets stolen? You would have to destroy roughly twelve Model Ds before the cost equals a single MiniMoog.

One of the MiniMoog's best features is the filter, which has a distinctively "smooth" sound. It's hard to describe in words but it has a smooth, rich, full-bodied sound. The MiniMoog has an audio input that can feed external sounds into the filter, and so does the Model D, so I decided to try it out:

This video also contains some remarkably clear footage of my right hand.

In this video the Model D's oscillators are turned off. Instead I'm feeding the sound of a Korg MicroKorg into the filter. Ordinarily this would result in silence, because you need some way to trigger the Model D's envelopes - there isn't a way to just disconnect the envelopes or force them to be always-on.

Therefore I'm using the gate output of my Arturia Beatstep as a gate source. To complicate matters the Model D has separate gate inputs for the loudness and filter envelopes, so I have to use a stacked splitter cable to trigger both of them. Notice how the cable running into the LC GATE input - above and to the right of the FILTER EMPHASIS control - has a second cable coming out of it, leading into the FC GATE input.

The BeatStep is feeding notes into the MicroKorg via MIDI, and the end result is a Korg MicroKorg with a Model D filter, or alternatively a Model D with a MicroKorg's oscillators. Ironically the MicroKorg has a bunch of analogue-sounding presets, so the end result still sounds like an analogue synthesiser. It would be fascinating to put a Yamaha DX7 or something obviously sampled through the Model D instead. That is for the future.

Let's take a moment to reflect on the unlikely renaissance of analogue synthesisers. Actual genuine analogue synthesisers with analogue circuitry, not software emulation. Few people in the 1990s would have guessed that CV/GATE would make a comeback in the new millennium, but here we are, with no less than two analogue recreations of the ARP Odyssey on the market, plus a bunch of affordable compact keyboard synths from Korg. Even Arturia, who make software instruments, now sell an analogue synthesiser.

Also, I have learned to spell millennium correctly. That's not much use in 2019, but who knows. Perhaps Chris Carter's Millennium will make a comeback and I will find myself needing to write about it. There's an easy way to remember how to spell millennium. It's like accommodate. It goes two-two. Two-two.

Philippines is one-two, Mississippi is two-two-two, but millennium and accommodate are two-two.

Two-two.

Korg ARP Odyssey: Master and Servant

It's Christmas! Don't forget the pancakes. Let's have a look at the Korg ARP Odyssey, an analogue synthesiser from the super-funky-fragilistic 2010s. Specifically 2015. What a year that was.

I've always wanted a proper analogue synthesiser. They fell out of fashion in the early 1980s, when I was young. For a very brief period they were available cheaply on the second-hand market, but analogue synthesisers are inherently awesome, so prices slowly crept up.

Furthermore owning an analogue synthesiser was awkward. A lot of musicians used them as sample sources, recording bass notes and sound effects into a sampler, but if you wanted to sequence an analogue synthesiser with MIDI you needed a special adapter, because analogue synthesisers generally predated MIDI. Part of the appeal of analogue synthesisers was their array of knobs and sliders, which allowed for real-time control of the sound, but after years of being gigged it was hard to find a used synthesiser that didn't have crackly pots. And if a voice card went pop, or a key fell out, getting hold of spares was a difficult undertaking.

Which is where the Korg ARP Odyssey steps in. It's a modern recreation of the 1970s ARP Odyssey made by Korg, but with MIDI, even USB. It mimics the sound of an Odyssey but the internal components are all new, although they're still analogue. And it doesn't smell of dust, or at least mine doesn't smell of dust.

The original Odyssey came into the world in 1972 and remained on sale until ARP Instruments went bust in 1981. In its day it was very popular, but the synthesiser market was very small in the 1970s, so even though it sold well it was hard to find on the used market in the 1980s and 1990s.

What was the ARP Odyssey? It was a two-oscillator monophonic analogue synthesiser. Technically duophonic, but I'll get to that later. Made by ARP Instruments of Lexington, Massachusetts. The company was named after Alan R Pearlman, the founder.

ARP's first product was the ARP 2500, a large semi-modular system that resembled the engineering panel of an old airliner. It was aimed at universities and other research institutions, because in 1969 very few rock musicians used synthesisers. One of them pops up at the end of Close Encounters of the Third Kind:

The humans use it to communicate with the aliens. Do you remember when airliners had a flight engineer? The flight engineer sat behind the pilots and monitored the engines, trimmed the fuel, deiced the wings etc. If something went wrong with the engines it was the flight engineer's job to climb onto the wing with an ice axe and a tether.

Fortunately advances in technology made the role superfluous in the 1970s and ever since then airliners have only had a pilot and co-pilot, and there are constant rumours that the co-pilot will eventually be eliminated as well. The last airliner with a flight engineer was Concorde, because things happened quickly on Concorde and the pilots needed a third pair of hands.

But enough of this banter. ARP followed the 2500 with the 2600, launched in 1971, which slimmed the 2500 down into a suitcase-sized panel that was complex enough to make weird sounds but simple enough that rock musicians could understand it. The 2600 was expensive but looked the business. Nowadays it's a valuable classic. Jean-Michel Jarre used it throughout his career, and I know this because his albums list the kit he used:

At the top Equinoxe, at the bottom Equinoxe

The Odyssey was essentially an ARP 2600 simplified even more, into a keyboard unit that could be taken on gigs. The Odyssey eliminated the 2600's patch cables, replaced the third oscillator with a dedicated LFO, and packed everything into a relatively compact but hideously ugly metal case.

During its life the Odyssey was the arch-rival of Moog Music's MiniMoog, which had one more oscillator and a simpler interface, against which the Odyssey's synthesiser engine was more flexible, adding ring modulation, sample and hold, oscillator sync, pulse width modulation, and independent frequency modulation for the two oscillators.

There were several different versions of the Odyssey; cosmetically the early ones had a white panel, mid-period Odysseys had a black panel, and late-period Odysseys had a black panel with bold orange letters. The later ones look best. Early Odysseys had a pitch bend knob, later Odysseys had three pressure-sensitive pitch and modulation pads:

The pads aren't very good. You have to push them really hard. It's easier to twiddle the oscillator tuning sliders.

The biggest internal change between different models was the filter. The original filter was terrific but infringed on Moog's patents, so ARP modified it. Unfortunately the second filter wasn't as good. It was duller and tended to lose all of the bottom end when it resonated. Later models had a third filter design which was better than the second but still not as good as the first.

In a neat touch the Korg ARP Odyssey has all three filters. I use the first one most often, the third occasionally because it sounds like acid house, the second one not at all.

The Odyssey is a class-compliant USB device, e.g. you don't have to install drivers to get it working. It accepts note on, note off, pitch bend (on the module only), but nothing else. If you want to store patches, you have to remember them in your head! The mode switches change the MIDI channel. By default it's set to channel one.
I can't find enough images of Odyssey back panels to conclude anything from the serial number.

The TRIG IN connector lets you hook up the Odyssey to a drum machine (for example) so that notes trigger in time with the drum machine's clock. Unfortunately the Odyssey doesn't have an arpeggiator or sequencer, so this is less useful than it sounds, although it would tighten up your keyboard timing.

The main output is a balanced XLR mono jack. The audio input is unbalanced mono.

What does the Korg ARP Odyssey sound like? Have a listen to "Tar" by Visage. The very first sound is an Arp Odyssey oscillator sync patch:

Here's a little demo in which I show off some of the synthesiser's features. The first thing is external audio - you can feed an external signal through the filters. If you send a signal to the Gate In port, or use the LFO to trigger the gate, you get a wub-wub-wub gated effect:

That's right. Wub-wub-wub. Mid-way through the video I demonstrate how duophony works. If you hold two keys the Odyssey assigns the lowest note to one key and the highest note to the other. If you play duophonically with the ring modulator turned on the results are not pretty.

Throughout the video I've used a light reverb but no other effects. Sonically the general stereotype in the 1970s was that the MiniMoog was "smooth" and the Odyssey was "aggressive", and I can understand that. The Odyssey's filters aren't as powerful, so it has a brighter sound than the MiniMoog, and its special effects - oscillator sync, ring modulation, pulse width modulation - all lend themselves to spiky aggressive sounds. Put through a chorus and tight echo it sounds massive. The resonant filter will do acid house squelchy sequences, and with the right settings - especially sample and hold filter modulation - it's surprisingly easy to emulate a Roland SH-101.

Analogue synthesisers from the 1960s and 1970s tended to suffer from pitch drift, whereby the oscillators changed pitch as they warmed up. The original Odyssey was apparently more stable than the competition, and Korg's re-release is more stable again. I find that it generally doesn't need retuning. This does raise one issue, though. Most analogue synthesisers had clicky knobs that allowed you to switch from one octave to the other. The Odyssey however has fine and course pitch knobs, which means that it's hard to switch octaves quickly. There's a global +/- two-octave switch, but what if you want to set one oscillator an octave lower than the other? You have to fiddle with one of the sliders.

The Odyssey can be driven by USB, MIDI, or CV/Gate, using a 1v/octave system, as per the original ARP Odyssey. In the following two videos I decided to make some music that uses the Odyssey exclusively, albeit fed through masses of effects:

The package includes a reprint of the original instruction manual.

Some people might find the casual use of "master" and "slave" offensive, in which case I suggest you rip out page 38 of the manual and burn it.

I live in the UK, where this kind of thing is probably legally defined as hate speech, so I have destroyed my copy of the manual. I'm surprised that Korg hasn't been prosecuted yet.

Korg's decision to re-release the Odyssey is slightly strange. Korg and ARP have no historical connection. The Odyssey is a classic, but it's not nearly as hip as the 2600. Functionally it overlaps with Korg's own MS-20, which was released a few years after the Odyssey (and re-released in 2013).

On a historical level it was used by a wide range of prog rock, jazz-funk, and latterly new wave acts during the 1970s, none of which are particularly fashionable nowadays. I've always associated it with Ultravox, Gary Numan, Visage, that generation of synthpop artists. However the big synth stars of the period mostly avoided it; Jean-Michel Jarre didn't need an Odyssey, Vangelis had a polyphonic Yamaha CS-80, Tangerine Dream and so forth used Odysseys only in passing, the Human League had a Roland modular system etc. About the only fashionable synthesiser act of the 1970s that used the instrument was Kraftwerk.

On a purely emotional level I've always associated it with cold, harsh electronic sounds and screaming lead noises. When I close my eyes I picture black and white 7" singles with photocopied cover photographs of oil refineries. I can hear the relentless dunka-dunka basslines of DAF, although apparently they used a Korg MS-20.

Perhaps it was a labour of love. There are several different versions of Korg's Odyssey. The original had miniature keys. A re-issue had full-sized keys. It's also available as a keyboard-less desktop module, pictured passim. Both keyboard and desktop models are available with cream ("Rev 1") or black/orange ("Rev 3") colour schemes, although internally the re-releases are identical.

I bought a cream Rev 1 desktop module because it was cheap and I already have a keyboard. Physically the Odyssey is made of bent pieces of metal. It feels hollow, but very tough. The body is smaller than the original, about 4/5ths the size in all dimensions.

The keyboard version has metal side plates that protect the sliders from damage - they act as a roll cage if the Odyssey falls face-down on the floor. The desktop version doesn't have these side plates, so you have to be more careful with it. Have you ever tried Purple Drank? It's a mixture of cough syrup and sweets dissolved in Mountain Dew. I like to add gin because I have some left over from Christmas. Make sure you don't spill any! It'll fur up your keyboard and stain your shirt. Don't drink it at work.

Does it make rational sense? The Korg Odyssey. Does it make rational sense? No, but human beings aren't rational and we don't live in a rational world. Look at the world around you. It's not rational. We are animals. We live, see the sun, then we die.

If you're a professional musician who makes a living from music the Odyssey might make sense if you play in a prog rock tribute band, but otherwise it's a waste of valuable space and money. Something like a Novation Bass Station has most of the functionality in a much smaller package. Sonically it's limited to just sawtooth and square waveforms (possibly sine if you're handy with the resonance slider), which will go a long way, but gets boring after a while. And it's more expensive than one of Korg's own modern analogue synths, such as the Monologue or Minilogue module, or for that matter the Arturia Minibrute or Microfreak. Or even Behringer's very own clone of the Odyssey. On a rational level it makes no more sense than a kitten, but like a kitten it's entertaining.

If you want the Odyssey sound, GForce's Oddity VST is apparently very close to the original, and it's also polyphonic, and it only costs £120 vs much more for the hardware. Former Ultravox keyboardist Billy Currie apparently now uses Oddity instead of an actual ARP Odyssey because it's a lot easier to carry a laptop to gigs than a bunch of discrete hardware. On the other hand the Korg ARP Odyssey is a thing, a physical thing of metal and circuits, that will exist and continue to work no matter how you tinker with Windows.