A filter filters out certain frequencies in the sound. There are four main types: a low-pass, high-pass, band-pass and notch, which are covered elseware in the glossary. Filters have two controls - the frequency control selects at which frequency the filter should start operating and the resonance control creates a peak just before the bit where it starts filtering out frequencies. This is used to create acid-type sounds....
Memorymoog
Basically (as much as the Memorymoog can be considered basic) this instrument is 6
Minimoogs in one box that will store 100 programmed patches. Its chief designers were
Rich Walborn and Ray Caster of the Norlin-acquired, "Bob Moog"-less Moog Music.
Each voice has 3 VCOs, with tuning controls for VCO2 and VCO3. Unlike the Minimoog,
the Memorymoog used Curtis 3340 chips as opposed to the Moog oscillators. Each
oscillator can be set on pulse, saw, or triangle (or any combination of the three). And,
like the Minimoog, the VCO3 can be used as an LFO to modulate the pitch of VCO1
and VCO2. But unlike the Minimoog, VCO2 can be synced to VCO1. Also, unlike the
Minimoog, you have a separate LFO that controlls all of the voices. The LFO is
switchable between triangle, pulse, positive and negative sine wave, square wave, and
sample-and-hold. Each voice also has its own 24dB/octave filter which has variable
keyboard tracking, switchable between 1, 1/3, and 2/3. The Memorymoog can also be
set on unison mode which makes it a mono synth using all 18 oscillators for one note! In
this mode you can switch between lowest, highest and last note priority as well as single
or multiple triggering.
"This is the true polyphonic heir to the Minimoog (forget the Polymoog -- please). The
Memorymoog's voice architecture is remarkably similar to the Mini's: three oscillators
per voice, with hard-sync option between osc 1 and 2 and the third usable in low-
frequency mode; time-honored 24dB/oct lowpass filtering with dedicated ADSR
envelope generator; well-equipped LFO; noise; and plenty of mode and trig- gering
options, including end-of-the-world. 18-oscillator unison."
"...Reliability was the Memorymoog's downfall, and it must have helped and hastened
the downfall of the Moog company itself. Yet the Memorymoog was not left stranded
after Moog's demise, and here in the 1990s, the instrument is probably enloying a
period of greater stability (in all senses) than at any other time, well catered to by
companies and fixits."
Description
"The busy anodized-aluminum control panel is carefully sectioned off into areas called
Oscillators, Filters, Modulation, etc, making the instrument smooth sailing as far as
knowing where to lunge for what. Programming controls occupy three-quarters of the
front panel, the remainder is taken up by controllers and their assignments-footpedaIs,
portamento, arpeggiator, displays and a keypad.
"The arpeggiator has been a particular hit with the dance fraternity: You can set up and
latch a pattern, transpose it freely by pressing new keys and then make real-time
changes to the sound using panel con trols -- increase modulation, alter filter cutoff, etc.
British synth composer Mark Shrieve is a specialist at such capers on a Memorymoog.
"Though the Memorymoog is rightly noted for strong, deep, large-scale sounds, it is also
capable of great subtlety and expression. The ability to use the third oscillator as an
audio source or a low-frequency modulation source (as on the Minimoog) can take
much of the credit for this, especially when employed for cross-modulation to introduce
interesting overtones and harmonics. The 24dB/oct lowpass filtering, too, is razor sharp
and has a variety of keyboard tracking strengths.
"The flexible third-oscillator modulation option is enhanced by its wide range of
modulation destinations (pitch of either dedicated audio oscillator, pulse width, filter
cutoff), and the filter's envelope generator can in turn, control the amount of osc 3`s
modulation.
"All of these combine to make a very expressive instrument, which is all the more
impressive because many aspects of the instrument are under- or un-specified. The
Memorymoog was released shortly before MIDI and just before the collapse of Moog
Music; you should be aware that the keyboard does not respond to velocity and that
MIDI was only implemented on the Memorymoog Plus or as a retrofit on early units.
Either way, there is no multitimbral capability. Why no velocity keyboard? It seems that
Moog stalwart Dave Luce experimented with keyboard velocity, using a ring oscillator
system built under the keyboard that extracted a control voltage. It was fast, but it
necessitated redesigning the contour generators, and for that, sadly, there was simply
no time ."
Modifications
"However, this much-loved beast has on its side the Lintronics Advanced Memorymoog
Modification, a comprehensive upgrade and MIDI implementation that not only plants
MIDI but grants control change status to most of the front-panel knobs and switches.
This means, for instance, that you can tweak in real time and have those real-time
sound changes recorded and subsequently played back from a MIDI sequencer. For
diehard Memorymoog fans, admittedly pricey upgrade will be like the second coming.
Further delights of the upgrade include program data transference via SysEx, some
user interface and tone-production enhancements and, it is said, 'dramatic
improvement' in tuning stability. Amen to that one, at any rate.
"One of the Memorymoog's more curious implementations is the security code,
designed as a failsafe to protect programs from being accidentally erased as users whirl
around the control panel stabbing this and pulling that (quite a typical scenario, in my
experience).
"Never cheap, and with a LAMM upgrade, horrendously expensive, the Memorymoog is
(for the time being at any rate) the final instrument bearing the Moog name. Ironically,
Bob Moog, who had nothing to do with the original design aside from providing the
inspiration for the Minimoog, is the man to turn to for the LAMM upgrade, which is
undertaken by Moog's Big Briar Inc. in North Carolina."