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Hands On: Moog MiniMoog

Time travel by synthesizer: David Mellor takes a look at the classic Moog MiniMoog.


Above: Studio Electronics' MIDI Mini; the guts of a MiniMoog in a 19" rack mount MIDI module.


Can you imagine a world without synthesizers? A world where every sound you hear is produced by vibrating wood, metal or air, or perhaps — in the most hi-tech instruments — by primitive electronic circuits limited to a very small range of thin, uninteresting tones. What a dull world this must have been, where if you wanted to use the sound of a Cor Anglais on your recording then you had to hire someone who could play the instrument, and if you wanted to produce a completely new sound, then you need to lash together various unwieldy pieces of equipment in ways in which they really didn't want to be lashed.

Once upon a time things were like this — then came Robert Moog, who invented the synthesizer as we know it (or more accurately, as we knew it, before the digital age). Without the work of Mr. Moog we would all still be practising our guitar riffs, trying to emulate Jimmy Page, or be keyboard players humping our Hammond organs from gig to gig while developing a fan base and a hernia.

How lucky we are now, with the assistance of synthesizers and sequencers to be able to conjure up a whole world of music at home. Technology has truly democratised music, bringing it to people as an activity in which to participate, rather than for the most part passively observe. It is plain that technology can never replace skill and natural ability, but whatever little ability you have can be amplified a hundredfold, and no-one now need feel left out of music because it is the exclusive preserve of the few. Do a bit of work, earn a few pennies, and the technology is available to you to bring out your musical potential to the full.

It occurs to may that there must be many Sound On Sound readers who aren't old enough to have been able to cast a covetous eye on the original MiniMoog synthesizer and its imitators back in the 1970s. I suspect that fewer still were fortunate enough to own one while it was still in its heyday. So perhaps a few words on the process of analogue synthesis will be useful, essential even, towards the understanding of the MiniMoog. And take my word for it, even though it seems to be very simple on the surface, you have to know what's going on to get the best out of it, or even any sound out of it at all. Furthermore, although its knobs and switches are few in number — with no LCD display and up/down buttons — its range of musical possibilities is vast. If you want those Moog sounds, there is no practical alternative even in 1992.

VOLTAGE CONTROL



The key to early analogue synthesis, where a very much wider range of sounds was available than on the electronic organs of the MiniMoog's period, was voltage control. Voltage control allowed many sound parameters to be controlled from two sources: the knob on the front panel, and a voltage input. For instance, the Voltage Controlled Oscillator, or VCO, can be tuned from the front panel knob, but this can only produce unmusical swoops. But get a keyboard to produce the voltage and the oscillator can produce a series of musical notes. Taking this a stage further and adding a low frequency oscillator, or LFO, can provide a modulating voltage which will create a vibrato effect.

Moving along the typical signal path of an analogue synthesizer we find a Voltage Controlled Filter, or VCF, which works in a very similar way: it can be set to whatever cutoff frequency you wish on the front panel, and additionally it can take a control voltage input from the keyboard, so the cutoff frequency can always stay in the same proportion to the frequency of the note being played. The third source of voltage control for either the VCO or VCF is the Envelope Generator, which produces a voltage signal which ramps up and down to create the attack-decay-sustain-release envelope with which we are familiar (although modern synths tend to have more complex envelopes, which may improve the overall sound but do little for controllability).

The Envelope Generator can control the pitch of the note being played, the cutoff frequency of the filter, and/or the Voltage Controlled Amplifier, so that the note played has a defined attack, decay etc.

So now you know all about analogue synthesis. There's not a lot to it in essence because, like all the best ideas, it was brilliantly simple and elegant to start with. I would like to put an analogue synthesizer in front of some of the designers of modern digital synths for a few hours. I am sure that once they had discovered just how controllable they can be that they would be looking at ways they could provide such power of control on their digital monsters which, let's face it, have grown up to be the latter day equivalent of the home organ with presets — and built in drum box if you're lucky.

THOROUGHLY MODERN MINI



When it first occurred to me that the Hands On series should look back at a few past masters of music production, I started doing the rounds of local hire companies who might have had a MiniMoog to lend me. But quite early on, someone mentioned the MIDI Mini (once known as as the MIDIMoog), and this rackmount MIDI-equipped version of the MiniMoog was just too good to miss. So instead of doing a Hands On review of the original MiniMoog, I have opted for the up to date version, a sample of which was kindly lent to me by The Synthesizer Company.

The MIDI Mini contains the electronics of a real Minimoog, removed from the original wood case and overhauled, and mounted in a 19" box with a new front panel and extra knobs and circuitry to provide some new functions. Now, some people will insist that this is a sin comparable to scrawling glasses on the Mona Lisa. To some extent I agree that it's a shame to rip apart these wonderful old musical instruments — I mean, would you consider taking apart an antique Stradivarius violin and modernising it, just because the original didn't match currant tastes?

Actually — interesting bit of the history of musical technology coming up — this is exactly what happened to almost every example of the work of the old masters of violin making. Their instruments were too soft in tone for the requirements of the up and coming composers of the 18th and 19th centuries, so one by one they were taken apart to be internally and externally modified so that they would perform better.

This exactly parallels what is happening now. They didn't build new violins to replace the old, because they had lost the secret of how to do it. No one, to my knowledge, is currently building an instrument with the sound and controllability of the MiniMoog, because modern production techniques are geared to turning out digital integrated circuits, and the old ways of manufacture would be uneconomic. So now we are faced with the fact that to make a MiniMoog usable for modern music, it must have a MIDI interface, and this inevitably means altering the original. And once you have made the decision to modify a Moog, why not go the whole way and bring it totally up to date as a rack mounting unit? If you object to this, you had better start up a synthesizer manufacturing business and develop an alternative product, because that's the only way this is going to stop.

TUNING UP



So you thought tuning your synth was a thing of the past? Indeed, how wonderful it is just to be able to switch on and play without having to check your tuning every time you want to do a bit of recording, or present your musical wares to the public. Guitar players still have to do it, but those clever tuning checkers are a real help, and should be made compulsory for all string pluckers (and sampler owners for that matter — perhaps I'll tell you about their sampling applications some time).

The problem with analogue circuitry is that it is inherently unstable. Take a common or garden transistor for instance. Its output current is dependent on the input current and... guess what? Temperature. The transistor, which is the building block of virtually all analogue circuitry, is affected by variations in room temperature. So, even with all manner of compensating techniques, any transistor-based circuitry is bound to be prone to the temperature, and oscillators, which ideally should be accurate to at least one part in a thousand, are first up for producing noticeable problems.

Now you might suspect that tuning an analogue synth is as easy, with the aid of a stable pitch reference or a tuning checker, as tuning any other instrument. Not quite, because not only do you have to check the tuning, you also have to make sure that the scaling is correct. If the scale is incorrect, then you will find even if one note is in tune, the rest would be out of tune. So the first thing you have to know about any MiniMoog is that these things need to be checked, and adjusted if necessary, otherwise you might lay down a track that is impossible to overdub to in tune, even by retuning or using varispeed. Hopefully, the scale tuning of the MiniMoog that you find yourself sitting at will be very close to perfect, but if it isn't then you have a job on your hands. Since this is far from being a current instrument I think it would be a public service to describe how to perform the tuning procedure — see separate panel.

WHAT? NO PRESETS?



Can you imagine a synthesizer that you have to reset totally each time you want to use a different sound. And to make 'presets' you must have a wad of blank charts showing the front panel controls for you to write in your settings? Did anybody ever get round to producing any useful music with synthesizers in the old days?

Well, things were very different then, and people's expectations were lower. You didn't expect to be able to buy a voice card with 100 new and excitingly different sounds pre-programmed and ready for you to use. You had to start off each time with a basic idea of the sound you wanted, and sufficient understanding of the instrument to be able to get from square one to that elusive perfect bass, or whatever. Let's take a trip around the instrument and see what we can get out of it.

Figure 1. A Classic MiniMoog bass sound.


Figure 1 shows a classic Moog bass setting, and you will find that it is indeed fuller and richer than modern digitised equivalents. Is it better than a sample of an original Moog sound? Too damn right it is, because you have full hands-on control of the sound at all times, and the MiniMoog itself can modulate a sound as you play in ways your sampler cannot. And from this starting point it is so easy to fine tune the sound, to exactly what you want to hear, that you can't help but wonder how on earth we ever let manufacturers deprive us of those wonderful things called knobs. Figure 1 will serve as an aid for me to describe how the Moog does its stuff, and will also act as a starting point to move onto some other fine Moog features.

OSCILLATOR BANK



The starting point for the sounds themselves is obviously the Oscillator Bank. Some other synths of the time had only one or two oscillators, but the MiniMoog has three, and the difference is vast. Each oscillator can be set to ranges from a basso profundo 32' up to tin whistle 2'. The description as a certain number of feet corresponds to the way church organ pipes are labelled. A pipe of 8' length, for example, will produce the C two octaves below a piano's middle C on the piano. The overall tuning of the instrument, for which there is a knob in the Controllers section, affects all three oscillators equally, but Oscillators 2 and 3 can have offsets applied which are normally used to thicken the sound up. The best part of it is that you can just reach out and do this. You don't have to call up the 'Oscillators' page, move the cursor to the right spot and hit a nudge button several dozen times to do it. You just do it. Each oscillator can be set to play one of six waveforms, each providing different harmonic content. Oscillator 3 has an additional switch, the function of which I shall come onto shortly.

Moving to the right, there is the Mixer section. On the original MiniMoog this is rather awkwardly laid out since the two additional sound sources — the noise generator and the external source — are on the wrong side to make sense, and they split up the oscillators. The MIDI Mini arranges this much more sensibly. Each source has not only an on/off switch, but also a level control so you can set the right blend. My first inclination is to set everything to 10 and go from there.

The Modifier section is the heart and soul of the MiniMoog. The upper modifier is the VCF (voltage controller filter) and the lower the VCA (voltage controller amplifier) and they both have envelope controls which respectively control the changes in timbre and level over time. Looking at the the simpler VCA envelope generator we see that there are only three controls, for Attack, Decay, and Sustain. Whatever happened to the Release parameter that other synths have? The answer is that there is an additional Decay switch next to the keyboard, or in the oscillator section on the MIDI Mini, which can throw in a fixed amount of release. Not subtle exactly, but it offers enough control, and we should expect to find a few foibles on classic instruments such as these. I'm assuming you understand envelope controls, so I'll progress upwards to the more complex filter.

At the top there is the cutoff Frequency control, which affects the brightness of the sound. At some stage or other you may have heard that the Moog filter used to be considered beyond compare in the world of synthesis. Let me tell you that it still is. The 24 decibel per octave slope (a measure of how sharp is the filter's roll-off) gives it the cutting edge that other filters sadly lack even now. The Filter Emphasis Control performs the function that we would expect to be labelled 'resonance' these days, and the Amount of Contour determines how much effect the filter's three envelope controls have on the sound. From what you know now, you can get a massive variety of sounds, and there is still a whole lot more to come.

So far, we have had the Osc-3 Control switched on. But what does this mean? Simply that the frequency of Oscillator 3 is controlled by the keyboard. With this switch in the down (off) position Oscillator 3 becomes an independent low frequency oscillator. Flick the Oscillator Modulation switch to the right, and the mod wheel next to the keyboard (or your MIDI controller's modulation wheel if you are using a MIDI Mini) governs the amount of vibrato. The Range setting and fine tune knob of Oscillator 3 control the rate. Play with that for a moment, then switch it off and flick the Filter Modulation switch on (to the right). Now the modulation wheel controls the filter cut off frequency. This is a great effect, and I particularly love putting my guitar through analogue synths (many of which have an external audio input into the mixer section) and getting a lovely bubbly wah-wah effect, better than you ever get from a pedal.

If you really want to, you can modulate oscillator frequency and filter cutoff at the same time. In fact, this is an area in which the MiniMoog excels — producing weird sounds. Experiment with some of the higher ranges of Oscillator 3 and you'll start to get some pleasant, and unpleasant, growl effects, all classic analogue synth noises.

Of course there is still more to learn. Like the two Keyboard Control switches. Basically, if these are both off then the keyboard will have no effect on the cutoff frequency of the filter. Set switch 1 to the right and the filter will partially track, increasing the brightness as you go up the keyboard, but not very much. Switch both on and the filter will track the keyboard precisely. Different combinations of the switches gives you different amounts of tracking. One case when you need full tracking is when you use the Minimoog's extra oscillator. "Where's that?" you ask, "I see no extra oscillator." Well, if you increase the Emphasis (resonance) of the filter then it starts to produce a tone, at the cutoff frequency, through self-oscillation. This is great for whistley type noises, and for weird ones too. Also the white or pink noise source is good in small quantities to give added bite to a sound.

By now, if you have access to a MiniMoog, you should be getting some really powerful Techno sounds out of it. But there's still one control I have to tell you about, so that you won't use it in error. My feeling is that although revivals of all kinds of material have kept the music world alive during the late '80s and '90s, the world is not quite ready for this one yet: the Rick Wakeman style of portamento, or 'glide', that the MiniMoog allows. Please, please keep clear of it until at least 1995, by which time the various synth manufacturers ought to have realised that the MiniMoog does still have something to offer and that we really do need more synths that we can control. I would seriously recommend a spell with the MiniMoog to anyone. You will see what we have all been missing all these years.

Thanks to The Synthesizer Company ((Contact Details)) for the loan of the MIDI Mini.

WHAT???

If you have used older analogue synths before, then you will be perfectly aware of the following fact. If you have been brought up in the digital age, then this might come as a shock: advanced though it was when it first appeared, the MiniMoog can only play one note at a time.


MINIMOOG TUNING

Both the original MiniMoog and the MIDI Mini have three oscillators and a reference oscillator producing the standard 440Hz tuning tone. If you need to tune the instrument, I would advise ignoring the internal reference as a long term standard of correct pitch, because this might drift, or be incorrectly adjusted. Instead I would be inclined to use a modern tuning checker and set the VCO tuning directly; alternatively you could tune up the internal reference and use it to reset the VCO tuning during the session because it shouldn't drift over a short period. For the rear panel adjustments, use a screwdriver with an insulated handle.

Figure 2. Tuning patch.


TUNING OSCILLATOR 1

1. Turn on the power switch (on = up) and allow the instrument to warm up for 10 minutes before making adjustments.

2. Set the controls as shown in Figure 2, and make sure the pitch bend wheel is in the centre position.

3. Switch on the A440 reference tone.

4. Switch on the Oscillator 3 Mixer switch. Adjust the Oscillator 3 Frequency control to create a perfect unison with the reference tone.

5. Switch off the A440 reference tone.

6. With Oscillator 3 on and now tuned to A440, switch on Oscillator 1. Press and hold high A and tune for near zero beating with Oscillator 3 (two octaves below) by adjusting Range 1 on the rear panel. Fine tune for perfect zero beating with the front panel Tune control.

7. Release high A and depress and hold low A. Adjust Scale 1 on the rear panel for perfect zero beating with Oscillator 3 (one octave above).

8. Return to high A and observe that adjusting Scale 1 has a slight effect on the range. Repeat steps 6 and 7 until perfect zero beating is obtained at both low and high A.

TUNING THE OSCILLATOR RANGE SWITCH

1. With Oscillator 1 on, high A pressed, and zero beating with Oscillator 3 (440Hz), switch the Oscillator 1 Range control on the front panel to the 32' foot position and adjust the Octave control on the rear panel for perfect zero beat tuning.

TUNING THE REMAINING OSCILLATORS

1. Return the Oscillator 1 Range switch to the 4' position.

2. Turn off Oscillator 3 using the Mixer switch.

3. Turn on Oscillator 1 and Oscillator 2.

4. Depress high A and hold. Adjust Range 2 on the rear panel for near unison with Oscillator 1. Adjust Oscillator 2 front panel Frequency control for perfect unison.

5. Release high A. Depress and hold low A. Adjust Scale 2 on the rear panel for perfect unison. Repeat steps 4 and 5 until perfect unison is attained at low and high A.

6. Switch off Oscillator 2. Switch on Oscillator 3 and click up the Osc-3 Control switch on the front panel.

7. Set the front panel Oscillator 3 Frequency control to zero.

8. Press high A and hold. Adjust Range 3 on rear panel for near unison with Oscillator 1. Adjust Oscillator 3 front panel Frequency control for perfect unison.

9. Release high A and press and hold low A. Adjust Scale 3 on rear panel for perfect unison. Repeat steps 8 and 9 until perfect unison is attained at low and high A.

10. Take a break!


MIDI MINI ADDITIONS

The MIDI Mini version of the MiniMoog, from Studio Electronics, offers enhanced features to bring the original instrument right up to date. These include:

MIDI velocity control of the VCA level
MIDI velocity control of the VCA cutoff frequency, with variable sensitivity
Additional low frequency oscillator
Additional LFO or noise generator can be used as a modulation source
MIDI modulation wheel control of low frequency oscillators
MIDI modulation wheel control of filter cutoff frequency
Aftertouch modulation of filter cutoff frequency
Oscillator 2 can be synced to Oscillator 1
Oscillator 2 can be routed to Oscillator 3 or filter
Filter envelope can be retriggered with each key press or only on staccato key presses
Selectable low, last or high note priority
Octave transposition switch
MIDI channel selectable


Also featuring gear in this article



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DIY

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Training and Education


Sound On Sound - Copyright: SOS Publications Ltd.
The contents of this magazine are re-published here with the kind permission of SOS Publications Ltd.

 

Sound On Sound - Jun 1992

Topic:

Vintage Instruments


Gear in this article:

Synthesizer > Moog > Minimoog


Gear Tags:

Analog Synth
Monosynth

Feature by David Mellor

Previous article in this issue:

> DIY

Next article in this issue:

> Training and Education


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