…but what happened to the Opus 1 and 2? Were they banished from Moogland or something? 
The 3 refers to the fact that the instrument consists of three sections - Strings, Organ and Brass.
Mal
Ah! That was a question I’ve been wondering about for awhile now. Thanks!
What does it sounds like, Mal?
I have always had a soft spot for the Opus3 . . some people say it’s a cheesy organ but I have always found it easy to get great “synth like” tones out of it.
The internals are very “organ” and it can take an age to warm up but once she gets going it’s the type of thing that you’ll keep coming back to . . a unique sound in any mix.
The strings are quite nice with there own multiband filter, which is quite unusual for a moog, and the strings filter can go quite “high Pass” and can sound a lot like a Jupiter 8 or Elka Synthex.
The String section has it’s own chorus which is just lovely, you only have a choice of fast or slow rate but somehow that doesn’t matter as both work great. You have full depth control and you can also delay start the chorus which makes the strings start off thin and cold sounding and then warm up as you hold the notes down.
The Brass section is rather simple with just controls for footage 16’ 8’ and 4’ and a control to send the brass sound to the inbuilt filter or to a “preset filter”. What’s quite nice about this is that moog have somehow made the preset filter sound VERY punchy and brassy, it’s quite hard to get the same sound out of the inbuilt filter so you do tend to use the preset filter if you want a traditional raspy brass sound.
The Organ section is the let down but only if you think of this as an organ, playing the Organ on it’s own is not advise but use it to faten up the strings and brass and it works really well. Also it is possible to mix the organ sound into the chorus (but then the strings can’t use the chorus) and also to mix the Organ sound into the filter (but then the brass has to use the preset filter setting). This can add a lot of variation to the Organ sound and actually make it sound quite synthy.
The Filter on the Opus sounds more “moog” to me then a lot of other moog monosynths. This thing can scream when opened and does a fine job at making the Opus more synth like . . add that to the LFO with it’s wide parameters like FM modulation and delay and suddenly you have an excellent sci-fi sound maker. All this control and in stereo . . and more importantly FULLY polyphonic.
I used to have a Prodigy on top of my Opus and found it to be an excellent match sonically . . . often the Opus would sound more synth like then the Prodigy . . It can also sounds quite like an Elka Synthex (and naturally a Polymoog), probably to do with the very charismatic chorus and modulation and it’s very “Vintage” sound.
The Unknown
If you are interested, my Opus is up for sale at the moment, going for £475. Time has come to clear down some of my collection and this has to go . . I will no doubt be sampling some of the sounds on it before I let her go though!
I’m in South London . . . let me know if you are interested
Mal
Alas, currents funds (and lack of studio space) won’t allow me to by this beast, but somebody will, no doubt. Full polyphony is pretty astounding for an instrument this old. How were they able to achieve this? I have heard it said that the Opus 3 isn’t a true synthesizer, so I imagine it is less sophisticated in the sound generation department, thus allowing more electronics to be dedicated to the keyboard?
The Opus3 is an organ . . it uses a playback system called “divide-down” common in organs and string machines where pitches are created for the top octave and then the oscillators are divided, creating lower notes . . . but from the same sound source facilitating polyphony.
The difference with the Opus compared to some of the other combo instruments of the time is that the output is fed into a real moog ladder filter and everything after the organ style sound sources (strings/organ/brass) is basically a monosynth.
This all sounds great and sets the Opus above many of it’s competitors but you can hear it’s limitations when you try to hold notes . . or double trigger the same note. As there are only one VCF and one EG per all notes played it is not possible to retrigger the envelope of a solo note - this would reguire a filter and envelope generator per mote (that’s why polysynths only have a limited number of playable notes . . 4 voice, 6 voice, 8 voice etc).
Moog created a couple of release “modes”, standard trigger where the envelope does not open if notes are held down and then a “playagain” mode where each time you play a note it re-pumps the envelope . . . can be quite playable.
The Opus is no less sophisticated then a Prodigy, just the initial sound making side of it uses different technology . . in fact there are several very high profile synths that use this technology . . . like the polymoog and Korgs excellent and expensive PS3XXX modular systems.
Mal