The key to synthesis, where a very wide range of sounds is possible, rather
than the strictly limited range offered by electronic organs of the Minimoog’s
period, is in voltage control. This means that every parameter, or at least
most parameters, can 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 – mild, rich or extreme in intensity.
Moving along the typical signal path of an analogue synthesiser we find a
Voltage Controlled Filter, or VCF, which works in a very similar way: it can
be set to whatever cut off frequency you wish on the front panel, and additionally
it can take a control voltage input from the keyboard, so the cut off 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 from modern
digital synthesisers although modern synths have more complex envelopes which
may improve the overall sound but do little for controllability. The Envelope
Generator may control the pitch of the note being played, the cut off frequency
of the filter, or alternatively the Voltage Controlled Amplifier so that the
note played has a defined attack, decay etc.
So know 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 synthesiser 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 could do with looking
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 early on,
someone mentioned the Midi Moog, as I think it was once known, but is now called
the Midi Mini. From what I knew already, this rack mounting MIDI controllable
version of the Minimoog was just too tempting 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 Synthesiser Company.
Now some people are going to say that it’s a sin comparable to putting
glasses on the Mona Lisa, but what I have to tell you about the Midi Mini is
this: it is 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 all the new functions. Yes. I agree that
it’s a sin and 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 music 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 eighteenth and nineteenth centuries so that one by one they
were taken apart and 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 production techniques have moved
on to 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 synthesiser manufacturing business and develop
an alternative product because that’s the only way this is going to stop.