Monday, October 31, 2011

Solaris Architecture, part 2: Control Sources

In Part 1, we looked at the audio signal generators, processors, and routing. In this part, we'll look at the control signal sources. To recap, these are:
  • Six envelope generators
  • One looping envelope generator
  • Four lag processors
  • Arpeggiator
  • Step sequencer
  • One envelope follower
  • Velocity and aftertouch
  • Performance devices: Joystick, ribbon controller, assignable buttons, and assignable knobs
  • Expression pedal input jack
  • MIDI continuous controllers
The six envelope generators are of the DADSR (delay-attack-decay-sustain-release) type. EG 6 is hardwired to the final VCA, although any of the VCAs can be routed to other destinations. The minimum time for any segment is 0.1 milliseconds and the maximum is 20 seconds. A useful feature is the ability to slope the sustain segment, instead of it having it be a constant level. The time of each segment can be modulated by velocity, key tracking, mod wheel, or one of four MIDI continuous controllers. The looping envelope is actually a universal event generator; in fact it is quite similar to the Encore Electronics UEG that I reviewed last year.

The lag processors do what you expect; you can route other signals through them to smooth transitions. (You don't have to use the lag processors to produce key portamento; each oscillator has its own glide settings.) The envelope follower produces a control signal proportional to a signal fed to it (presumably from an external input).

The Solaris is unusual in that it contains both an arpeggiator and a step sequencer. I have not played with either one very much yet. The arpeggiator can use internal clock or sync to MIDI clock. It does the usual up, down, up/down, random, and as-played patterns. The sequencer is a four-row, 16-step sequencer with variable step lengths. and it can be routed to any destination -- it isn't tied to oscillator frequency. Both have the ability to use stored patterns that the user can create, but the software to edit the patterns is not finished yet.

The keyboard generates velocity, release velocity, and aftertouch. There are scaling and offset parameters which can be stored in each patch, which apparently are capable of making velocity and aftertouch do some rather strange things. According to the manual, the Solaris will receive and respond to polyphonic aftertouch, although it will not generate it. The keyboard has the usual pitch and modulation wheels to the left; the pitch wheel is spring loaded while the mod wheel is not. The pitch wheel does not appear to be routeable to any parameter other than oscillator and rotor pitch. The mod wheel is defaulted to control the amount of LFO 5 that is routed to oscillator and rotor pitch, but it can be routed to other destinations.

The Solaris has an array of performance controls besides the pitch and mod wheels, the most notable of which is the ribbon controller that runs the span of the keyboard. In my tests with it, I found the ribbon controller to be very smooth and glitch-free. It can be configured so that the point where you first touch it becomes the zero point, in the style of the much-vaunted ribbon controller on the CS80. It can also be configured to hold its last value.

There are buttons to turn the arpeggiator and sequencer on/off, and a "hold" button that does what a sustain pedal does, except that it is latching; once you press the button, you can take your hands off the keyboard and it will keep playing. There are two assignable buttons that can send a constant value to a modulation destination. One of the preset pages on the large window allows the bottom row of knobs underneath the window to be used as assignable knobs. And there is a jack for plugging an expression pedal.

In the MIDI Setup, there are five controller designations labeled CC1-CC5. You can assign any MIDI continuous controller number to these, and then they can be routed to any modulation destination. Finally, it appears that every patch parameter is accessible via the MIDI NPRN mechanism, although it is possible that not all will respond in real time -- it would take a long time to try every possible value.

This wraps up the quick overview of the Solaris architecture. It's quite possible that I will later find out that some of what I've written is wrong; I'll make corrections in future posts. I'm getting a lot of requests for a demo, so I'll get that up in a day or two.


Brian said...

Nicely done. I do think the Solaris is THE best-sounding and best-designed synthesizer made. I wish i could afford one. It seriously rivals the tone qualities of early modular synthesizers, with smart user interface to make programming really easy. Jealous!

Brian said...

Nice writing, solid, easy to follow. Thanks for the blog, just getting into it...