First on the list is the classic ‘foot pedal’ – a staple of practically all electronic musical instruments for decades. They can be used to modulate a part of the synthesizer, or to change patches – making them especially useful in a live situation. Suitable MIDI pedals are relatively cheap, but make sure to shop around for a solid, reliable one – it will get an awful lot of bashing from your foot.

‘After touch’ is a capability of many modern MIDI keyboards and synthesizers, and is based on the concept of the player pressing harder on the key(s) to create a modulation effect. ‘Polyphonic after touch’ is a more advanced version of this, which allows different levels of after touch modulation to be processed simultaneously – similar to concept of having polyphonic or monophonic envelopes.

MIDI knob/fader controller boxes have been around for a while, and are useful in particular for controlling software synths. They also come in handy for programming tricky synths, which started with dedicated controller units for synths, such as the Waldorf Microwave controller made by Access, or the bizarre ‘Jellinghaus’ for the Yamaha DX-7. For something even more special, check out the ‘Monome’ – a box of buttons that light-up like a Christmas tree for controlling MIDI applications.

Ribbon controllers are useful for creating spectacular pitch-bending effects, and are often also able to modify other aspects of a sound. Although not included on most synthesizers, they are currently available separately from Doepfer, and several synthesizers feature dedicated ribbon controllers, such as the Alesis Andromeda A6 and Yamaha CS-80. A recent product based on the ribbon controller idea is Analogue System’s ‘French Connection’, which features a finger-controlled ring moving up and down the keyboard to create abnormal modulation effects.

Joysticks have a use apart from video games, and these can be found most popularly in the Prophet VS and Wiard modular synth systems. They can be programmed to control most aspects of the synthesizer’s sound, and are particularly useful in the Prophet VS to control the blending of the oscillator’s wave shapes. The Korg ‘Kaoss Pad’ follows a similar idea to joysticks, and uses a touch sensitive pad (controlled with the finger) to send out MIDI data based on the X-Y position of the finger on the pad.

• Modcan – modcan.com: Beautifully designed and extremely expensive, the Modcan modular system is a delightful selection of ever-so-slightly eccentric modules which generally sound excellent. The product range is divided into the older ‘A’ range and the newer, prettier ‘B’ range depending on your taste. Despite the nice looks, superb sounds and top-notch build quality, the Modcan modular system is not cheap, and with the relatively newly released analogue sequencer setting you back over one-and-a-half grand, the Modcan is only for those prepared to pay for extremely high quality gear.

• MOTM – synthtech.com: ‘Mother Of All Modulars’ are an established current producer of modular gear, providing modules pre-built (expensive) or as DIY packages (not quite so expensive). Complete systems are not sold as a whole, encouraging users to build and customize their own systems. The equipment itself is of good quality and sounds excellent, but the narrow selection of modules is somewhat limiting – making MOTM a good starting place for a modular synth, but a large system would soon need to expand into other module manufacturer for more features.

• Oakley – oakleysound.com: UK-based homebrew manufacturer ‘Oakley Modular’ have established themselves as a semi-popular provider of DIY modules for users to build themselves. As of late 2007, the company is releasing new modules for their current series, which look excellent and highly creative, including a discrete analogue filter, and an overdrive module. In future they should become a more popular supplier of modular synths, and increase their currently rather small user base.

• Synthesizers.com – synthesizers.com: At the start of the millennium, robotics genius Roger Arrick decided it would be a good idea to start producing imitation Moog Modular synth gear for everyone who missed it the first time. After a slightly shaky start, the ‘.com’ series of synthesizer modules has taken off, and have become the quintessential choice for those who want the sound and feel of classic Moog gear.

A somewhat uninspiring selection of modules are available at reasonable prices, but it would be nice to see some more exotic modules that weren’t part of the original Moog Modular range available – although the superb sequencer modules make up for this somewhat. Despite this, the systems are reliable and well-built, and include a great monthly payment plan for an introductory system if you’re a broke student like me.

• Wiard – wiard.com: ‘Wiard’ modular synthesizers have been around for a while now, and have established a reputation for sounding good, and being difficult to get hold of. They sport some creative modules on offer, and look stunning in PPG-style blue, but are very expensive – limited to the high-end market only unfortunately. Regardless, they are an excellent maker of modules to choose for a top quality system.

In conclusion, I would like to add that although there are more modular manufacturers out there, if you’re aware and conscious with intent to buy from them then you don’t really need to be reading this. These modular synths are all reliable, well–built, have excellent customer service, and above all sound good. For those who are new to the world of modular synths, I would recommend sticking to well-known companies such as ‘synthesizers.com’ and ‘Doepfer’, as they are an excellent basis for a solid foundation as a modular synthesizer due to having pre-built systems ready to go.

• Analogue Solutions – analoguesolutions.com: Known perhaps more for their interesting range of discrete synthesizer gear, including the ‘Red Square’ and ‘Vostok’ semi-modular synths, Analogue Solutions also produce their own range of modular gear called the ‘Concussor’ series. Standard subtractive modules are available, as well as sequencing and utility modules, but more interestingly there are many percussion modules available, emulating the sounds of the drum machines of yesteryear. When was the last time you saw a dedicated Roland TR-808 cowbell module? If this is your thing, Analogue Solutions should definitely interest you.

• Analogue Systems – analoguesystems.co.uk: Furnished in delightful wood cases with a variety of excellent modules, ‘AS’s RS-Integrator product range include many different pre-built systems depending on the size of your wallet, as well as having all modules available for purchase separately. Fancier modules include a fantastic digital delay/sampler, and a vocal/phase filter bank. As well as modules, the company also produces the unique ‘Sorcerer’ controller keyboard, which can be filled with the synth modules of your choice, providing you with an in-built keyboard for expressive performance with your AS system.

• Blacet – blacet.com: At first I was in danger of thinking Blacet were yet another modular synth company (not that that’s a bad thing), but a quick look through their product line showed me otherwise. The choice of those who like to live a little (just a little, mind you), Blacet has established themselves as a solid provider of high quality modules, which sound better than they look – at affordable prices too. Top notch modules include the ‘Improbability Drive’, an analogue noise generator, and the ‘Binary Zone’ – a dedicated CV/Gate logic module.

• Cwejman – cwejman.net: Cwejman first came to prominence by creating the ‘S’ series of hybrid semi-modular rack synthesizers, but have recently released their own line of Eurorack format modules. A little speculation is necessary due to a lack of public opinion on the modules; however they reportedly sound and look as good the previous semi-modular synths the company produced. Not only that, but they look and sadly cost just as much too. Should you want to get involved with building your own Cwejman modular however, there is a huge variety modules available, the highlights of which include a dual oscillator module with a built in ring modulator, and two different compressors amongst other outboard-style audio modules – something other modular synth manufacturers have often ignored in the past.

• Cyndustries – cyndustries.com: The only (to my knowledge, anyway) modular synth company run by a woman, Cyndustries produces awesome looking and fantastic sounding bizarre modules, which while somewhat confusing to use in a system of their own, will definitely add something extra to existing systems from other manufacturers - take a look at the ‘Sawtooth Animator’ or ‘Super Psycho LFO’ for something really special. Cyndustries have also gained considerable publicity this year due to the release of their latest module called the ‘Zeroscillator’, which is specially designed for being used in other modular synth formats – at a fairly high price too.

• Doepfer – doepfer.de: Doepfer are a very popular of synthesizer equipment, including MIDI controller keyboards, sequencers, and a wide selection of modular gear. Their ‘A-100’ line of modules include a massive variety of various modules, ranging from standard oscillators and filters, to digital sampling oscillators and even a light controlled CV interface module! Although flexible and highly inspiring, some users have found themselves disappointed with the sound of the oscillators and filters, as well as build quality problems due to the size of the small modules and knobs.

The basic modules within most modular synths are as follows:

• VCO (Voltage Controlled Oscillator) – an analogue oscillator which outputs a set frequency by default, and has separate outputs for each waveform.
• VCF (Voltage Controlled Filter) – an analogue filter which includes different filter types such as low pass and high pass, as well as dedicated outputs for each mode.
• VCA (Voltage Controlled Amplifier) – an analogue amplifier module which usually includes the ability to combine multiple inputs as well as output a linear or exponential signal.
• Envelope (Generator) – an envelope generator which alters the voltage over the shape of the envelope. The envelope can be connected to control any part of the synthesizer, such as the amplifier or filter.
• LFO (Low Frequency Oscillator) – a dedicated LFO module is available from some modular synthesizer companies, but some choose to use existing oscillator modules set to a special ‘Low Frequency’ option instead.
• Mixer/Multiples – utility modules used for mixing or multiplying signals to other parts of the synthesizer.

Many other modules exist depending on particular modular synthesizer brands, such as ring modulators, sample & hold modules, and slew limiters. Step sequencers are also commonly used in larger modular synthesizers to send trigger signals to any part of the synthesizer – this is one of the many advantages of modular synthesizers, as the sequencer could be routed to control any part of the synth, not just the oscillator pitch.

Trigger signals themselves are one of the key parts of modular synthesizers, as they control the functions of most of the modules. ‘CV’ stands for ‘Control Voltage’, and determines the pitch of the signal which is sent, to control the note played. This sort of signal would be sent by sequencers and controller keyboards. ‘Gate’ is also a form of CV, but is used to specify when notes should sound – but not how they should sound. This makes it useful for modules such as sequencers and envelopes, as they are not pitch-dependant.

Some modular synths are not designed to create new sounds, but to modify existing ones. Such systems are known as ‘FX’ or ‘filtering’ systems. Many other types of modular synthesizer exist, such as special systems built purely for vocoding, sequencing, or use of a Theremin. Again, this is one of the advantages to modular synthesizers, as they are completely customizable by the user.

For those who enjoy the analog and vintage sound, look no further than the Boss Microrack range. They are half the size of a normal 19” rack unit, and come in lots of different flavours, including the highly regarded RBF-10 flanger and the RPH-10 phaser unit. Modules generally run for no more than £50/$100, so while they are getting on a bit and can break down, they’re so cheap you can afford to buy a new one should something go wrong. Boss also produced a small selection of ‘full rack’ effects around the same time, which sound equally as good and are equally as cheap, the highlight of which is the CE-300 chorus unit – you won’t find a great-sounding analog chorus effect for cheaper!

If you want to stay in the vintage domain but your wallet is of infinite size, look no further than Roland’s classic range of late 1970s rack mount effects. You’ve probably heard of the classic ‘Dimension D’ rack unit, which in good condition will most likely set you back a four-figure sum. Still, a little cheaper is the excellent SBF-325 chorus and flanger unit, which features extensive modulation capabilities for all things ‘detuned’.

Modern rack mount stereo effects are also manufactured, but sadly are few and far between. The eclectic synth company ‘Vermona’ produces a variety of gear, including their own ‘PH-16’ phaser, and one of very few rack mount ring modulators produced – the ‘RM-1’. Both are available cheaply, and don’t forget to check out their ‘Action Filter’ too. Speaking of which, external analog filters are the perfect compliment to a digital synthesizer, and are best placed at the start of the signal chain. The top dedicated filters around these days include the well-known Sherman Filterbank, and the newly released Schippmann ‘Ebbe und Flut’ – super expensive and super nice.

Of course, you may be wondering what the point of all these over-sized single-purpose effects is. Well, while on stage a cheap multi-effects box can be handy, nothing beats a classic piece of analog machinery processing your sound in the studio. And while analog synthesizers are important to this, don’t forget that analog effects in your signal chain are essential also, and can work wonders on non-analog sounds too – so keep your eye out for these bargains.

Analog - Monophonic: These things have been around since the beginnings of synthesis technology – after all, they are the simplest to create bearing in mind that they need only to have the facilities to produce 1 voice, and that they use less complex (but many would argue better sounding) analogue components. Examples: MiniMoog and ARP Odyssey.

Analog – Polyphonic: A polyphonic version of the above, meaning that they are able to play more than one note without compromising the other voices. In the early days these were gargantuan beasts with a sound to match, but the Prophet 5 revolutionised analogue polyphonic synthesizers due to its use of a computer microprocessor, giving it the ability to digitally store patches. Examples: Prophet 5 and Oberheim OB-8.

Virtual Analogue: The modern day equivalent of analogue polyphonics, these digitally powered synthesizers are able to play a large number of voices, store lots of presets, and never go out of tune as they are powered by a microcomputer. First introduced in 1995 with the Access Virus, they now feature in-built effects ad sequencers to add to their power. Examples: Clavia Nord Lead and Roland JP-8000.

Digital: A relatively short-lived group of synthesizers, mostly from around the 1980s featuring alternatives to subtractive synthesis. Yamaha pioneered this idea with their DX range of FM-based synthesizers, as well as contributions from Casio with their phase distortion technique, and Roland with their still very popular D-50 synth, which used a new type of synthesis called ‘Linear Algorithmic’. These synths, although responsible for the downfall of analogue machines, helped give musicians the ability to create completely new and unique sounds never heard before. Examples: Yamaha DX-7 and Korg M1.

Hybrid: Unique machines with special characteristics, so it’s hard to describe them all together. However, they are usually defined by combining analogue and digital technology together, or for introducing a new method of synthesis or major feature. Examples: PPG Wave and Ensoniq ESQ-1.

Semi-Modular: These are a long outdated combination of analogue monophonics with the patch points of a modular synth. This has the advantage of a fairly small synthesizer but which can be programmed with great complexity. Software technology makes this sort of synth architecture no longer necessary. Examples: ARP 2600 and Korg MS-10.

Modular: Analogue synthesizers which feature each of their individual components in separate units. These units (or ‘modules’) are connected by cables using the CV/gate trigger interface, and have the advantage that they are extremely flexible in terms of programming ability, and allow the user to add or remove modules as much as they want. Unfortunately, this also makes them difficult to program and high addictive (and therefore large and expensive). Examples: Moog Modular and EMU Polyfusion.

Overview Of Digital Synthesis

Digital synthesis is based somewhat (perhaps a little too much) on the concept of trying to emulate analogue/acoustic sounds, using different methods and techniques depending on the accuracy of the audible reproduction. Because these new methods of synthesis are computer-based, there are always limitations to what can be practically performed.

The four important methods used in digital sound synthesis are as follows:

Loose Modeling

‘Loose modeling’ consists of little or no real attempt to model sound. It is used to perform AM, FM, Walsh, and Wavetable synthesis.

Time-Based Modeling

‘Time-based modeling’ models sound in the time domain. It is used is granular synthesis, waveset distortion, and waveform composition.

Spectral modeling

‘Spectral modeling’ models sound in the frequency domain. It is used in additive synthesis, and re-synthesis (such as the Hartmann Neuron synthesizer).

Physical modeling

‘Physical modeling’ uses mathematical models of acoustical properties of instruments/components. It is used to create extremely accurate reproductions of physical sounds, such as mass & spring simulations, and ‘Karplus Strong’ synthesis – to create accurate sounding ‘plucked’ sounds.

These four methods can still use analogue components within their signal chain, but are digitally-based. In addition to this, different digital synthesis techniques exist, such as the previously mentioned ‘Digital FM’ synthesis, which is neither strictly digital nor analogue, and allows for more flexibility in terms of ‘complex’ modulation. FM synthesis tries (but fails to an extent) to be like analogue subtractive synthesis, by using Yamaha’s ‘operator’ concept, as well as LFO-like modulation. ‘Walsh’ synthesis is completely digital, and uses many square waveforms to create new waveforms. Unfortunately, it’s hard to predict the frequency spectrum that will be created through this technique. ‘Wavetable’ synthesis has been made popular by famous synths such as the ‘PPG Wave’ and Waldorf’s ‘Microwave’ series. It consists of using fragments of sampled sounds which are played back and looped like a sampler. To make life easier, standard features such as envelopes, filters, and LFOs are used.

A vocoder needs two inputs to function properly. A ‘carrier’ wave, and a ‘modulator’ input. The carrier is the sound you want to vocode through, and the modulator is your voice. The modulator takes your voice, finds the fundamental frequencies (important bits) of it, and converts them into levels of amplitude on a series of band pass filters (this is why some vocoders have different numbers of bands) – in general, the more bands available the more understandable your speech will be. These band pass filter signals are then passed onto the carrier wave where your final sound is created.

It’s important to remember that anything can be used as the carrier and modulator in a vocoder – it’s just that most people want to use speech as the modulator to achieve the classic robotic vocoder effect. For creative results, try running other synthesizers or even other instruments through the modulator input and see what results you get. The carrier wave should usually be a nice big synthesizer sound, such as a long saw wave pad or string sound, but anything with considerable depth and length will achieve useful results.

Like sequencers and onboard effects, vocoders have now become standard features of computer-based hardware and software synthesizers, and inevitably some will say that nothing sounds quite like a dedicated analog vocoder. Due to the analog voltage-controlled circuitry from the ‘golden age’ of vocoders this is true, but like most things in life you get what you pay for. The legendary Roland VP-330 will set you back at least a grand or so for one in good condition, while the equally-as-old Korg VC-10 is much cheaper and much naffer too. For a modern alternative, look into the dedicated Roland VP-550 or the Korg R3, or even something as small and affordable as the MicroKorg – it come with a microphone for a reason.

Remember that not all ‘robot voice’ sounds come from a vocoder – a talk box is often used (in ‘Robot Rock’ by Daft Punk for example), and recent years have seen the use of speech synthesis (anybody remember Microsoft Sam?) and auto-tune software becoming increasingly popular.

1. Beware of the tell tale dodgy synth seller signs. If he/she says “I’m selling this for a friend so I don’t know much about it” – stay away. If the ‘buy it now’ price is suspiciously low – stay away. Likewise, remember all the standard seller checks – such as feedback and payment options (in the case of eBay), and check the seller out by searching for his username on the net, and asking around for his reputation.

2. Get to know the seller before hand. Ask him questions such as how long he’s had it, what does he think of it, where did it come from. Ask him to post photo’s if he hasn’t already (actual photos that is – standard promo pictures are not useful), ask him to post sound samples, even ask him to post a video of it in action – this is a practice more and more synth sellers are doing due to the advent of technology such as YouTube.

3. Watch out for all the usual technical problems with old analogue synths. Time is not kind to synthesizers, and many synths have been gigged around and passed between hands many times. Dodgy soldering and clumsy work on the circuit boards are common problems, as well as the knobs and buttons on keyboards becoming rusty or filled with dust and dirt causing them to be sticky or unresponsive. Likewise, the keybed can be damaged – which is often an expensive repair job. If you’re buying new gear, make sure it has the manufacturer’s warranty still covering it for a while.

4. Know the reputation of the specific gear you’re buying. Juno 106’s are well known to actually be Juno 105’s when you get them, as one of the voice chips in them has a good chance of failing. Likewise, the Korg Polysix tends to have ‘leaky battery syndrome’ which can destroy the PCB and render the synth useless. Always check these common problems related to your synth before buying – ask the seller direct questions.

5. If the synth is local, always go and try it out. Sellers are happy to have a potential buyer come over and try it out – and if they’re not then don’t buy from them. Trying out the synth means you’ll know it works just fine (or not), it allows you to pick it up and take it home easily if you do decide to buy it, and you’ll make a new friend and probably get a free cup of coffee too.

6. Some synths just aren’t practical to mail around. The size of certain keyboards such as the Prophet T8 and Yamaha CS-80 or DX-1 are simply too big to safely mail halfway around the world. Don’t take risks with your money just because you want the synth now – wait however long it takes and find one local – rent a large van or truck if you want to be extra safe it reaches you safely.

7. Gear should be packaged properly. Too many times sellers fail to insulate the synth in the box with some sort of padding. This can be anything – old magazines and paper, foam, bubble wrap, just make sure it fits nicely so it won’t move about in the box. Don’t forget that your poor little synthesizer will be thrown in and out trucks and depots with extreme force by the delivery guys, and the last thing you want is it being broken while in transit.

8. When you receive the package, it’s a good idea to take the synthesizer out of the box before the delivery person leaves, so if it’s damaged you can write it on the delivery form or even refuse delivery. If this isn’t possible, check the ‘unchecked’ box on the form – if there isn’t one there to tick, just write it on the sheet.

Bearing all this in mind, it can seem scary to plunge into the world of second-hand synths. Do not fear though, as most of the sellers you will encounter are generally honest, genuine, pleasant folk who do care about making the transaction as smooth as possible. With time and experience you will soon be able to sniff out scams and bad sellers before its too late, providing you with many years of happy synth buying!

FM synthesis is based on two key things – a ‘modulator’ oscillator, and a ‘carrier’ oscillator. These oscillators usually both use a sine waveform, and from this the modulator oscillator works just like an LFO – because it modulates the frequency/pitch of the carrier oscillator. You can try this yourself on a normal subtractive synthesizer, by setting up a sine wave oscillator and an LFO, and using the LFO to modulate the pitch of the oscillator – as you increase the rate of the LFO, the sound becomes non-harmonic. Note that in FM synthesis, the word ‘oscillator’ is often replaced with the term ‘operator’. As you change the modulation of the carrier operator, the frequency of the carrier will constantly move up and down depending on how the modulator is set up (e.g. it’s depth and rate), and in doing this different harmonics are created (called ‘sidebands’), because these harmonics surround the carrier frequency depending on how it is modulated.

Because of the somewhat lifeless sound of the operators, FM synthesizers tend to include somewhere around 4-8 operators on a synth to spice things up. These extra operators can be routed in all sorts of different and interesting ways, called ‘algorithms’. For example, with the addition of an extra modulator operator, we can arrange the operators so that they go ‘’modulator 1’ & ‘modulator 2’ go into the carrier’, or ‘modulator 1 goes into modulator 2, which goes into the carrier’ – this being more complicated and creating a new waveform. Therefore, using many operators can produce unique and lifelike sounds unachievable with other types of sound synthesis.