I've been using Ableton Live since version 1, and it has become the primary workspace for my bedroom, IDM- ish electronic music. So I was excited to test drive Operator, which is the first new software from Ableton since Live's inception. Operator is a polyphonic synth instrument plug-in that works exclusively within Live 4. That's a pretty simple description, but a bit deceptive as Operator is really quite flexible and deep-and very intuitive. It also sounds great! It's primarily based around the concept of FM (Frequency Modulation) synthesis, which involves changing the timbre of a waveform (sine, saw, square, triangle, etc) by modulating it with another waveform with a frequency also in the audio range. What you get are more complex tones and an almost infinite depth of sound-creation possibilities. You can geek out more on FM synthesis at Wikipedia.org if you like, but truthfully, you'll never need to know any of the science to create cool sounds with Operator.
The specs are pretty straightforward: four oscillators, all of which can be routed to modulate each other in various configurations; an LFO section, which can be used as a fifth oscillator; a resonant filter section with bandpass, notch, hi and lo-pass filters; a pitch envelope, which can be routed to modulate any or all of the oscillators as well as an LFO section. Some extra bits unique to Operator: global Tone and Time parameters and a Spread feature. Tone is exactly what it sounds like and can be used to generate an extra bit of analog style "warmth" at the end of your routing. Time seems to stretch or compress the notes played and can drastically alter the attack and decay of any given sound. Spread seems to generate a richer, high-end- ish stereo chorusing, which is really pretty cool on certain sounds (although I found myself turning it down for most of my sound-design adventures). Almost all of the above can be edited and tweaked further by means of seven envelopes, offering ADSR-style flexibility as well as crazy loop, beat, and sync modes, which tie into your Live session's tempo and can generate rhythmic bleeps, boops and general weirdness.
Clearly, tweak-ability is not an issue with most of today's software synths, and Operator is no exception. What really sets Operator apart for me are two key elements: ease of use and affordability. The interface, like Live itself, is just amazing in that it gets out of your way and allows you to focus on actually playing music and working on composition as opposed to spending hours drudging through manuals. Actually, that's one of the minor gripes I have with Operator-there's no "hard copy" of the manual, like there is with Live itself (in PDF form). Instead, there are integrated "lessons" that are clear, informative, and cool, but they open up within their own Live session, which forces you to save your work and open a new session if you want to read the lesson. Not a big deal, but I kinda like having a PDF open in the background for occasional reference. Anyway, the design of the interface is simple, clean, and easily accessible; so I rarely found myself in need of manual. As for the cost, it's $149, which is less than a comparable software synth like NI's Absynth.
The sound, again, is great. Rich and deep analog-style sounds; or bizarre, edgy, digital FM craziness. Operator includes a ton of presets, including leads, pads, percussion, sound effects, etc; so it's easy to pick a starting point or reverse-engineer a sound to get what you want to hear. User presets can be saved and organized, and more presets can be found and downloaded via Ableton's online forum. For my test drive, I ran Operator within Live 4.1.1 on my 1 Ghz G4 Powerbook with 1 GB of RAM installed, using a Korg microKONTROL as a MIDI controller. With no other apps running, I noticed a CPU load of approximately 15-30% using most of the presets, with one instance of Operator running, alongside a few clips (loops) and minimal effects. Not bad at all, and certainly less than the bigger, more expensive soft-synths like the Arturia stuff. I've heard that CPU load is even less if you're running it on a PC. I tended to gravitate towards using Operator as a pad or lead sound, although it is flexible enough to generate really cool percussion and rhythm sounds (kicks, snares, hats, etc). I don't think you can pass external audio through Operator like you can with some soft-synths, but honestly, I have to experiment a little further to make that determination. That would certainly open up some audio-processing possibilities. Future update maybe?
All in all, Operator is a welcome addition to my Live setup and a lot of fun to play. Its tight integration with Live is huge (automation control over every single parameter- yo), and I'm sure I'll be using it more and more as a go-to sound design tool. ($149 MSRP; www.ableton.com