John Bowen’s Solaris synthesizer is an amazingly flexible machine.  While most playable keyboard synthesizers have a fixed (and simple) signal path derived from old analog synths, the Solaris is a semi-modular design.  Like a real modular synthesizer, you can patch its various components together in flexible ways.  It is not as infinitely flexible as a modular, but for practical purposes, there is little you can’t do.

The key to this flexibility are the four mixers.  While the synth has “hard-wiring” from OSC-Mixer-Filter-VCA by default for each of the four voices, this is not a path you have to follow.  The mixers are each capable of taking sound from four inputs.  These inputs can be anything that makes or processes audio in the synth from oscillators, to rotors, to filters, to insert FX, to the VCA’s.  This means that you can reconfigure the signal path in almost any way, and blend any combination of feedback or sequential processing you can think of.  Each mixer input (and the master out) can be modulated by any control parameter of the system, enabling full control of any of these audio signals.

This flexibility is dizzying at first.  Every section of the Solaris is full of options, and then you can combine them in almost any way.  How do you learn to use this beast?  Well, one easy way is to arrange the signal path to mimic a successful historic analog synth.  The Solaris can easily create the signal path of almost any synth you either owned or always wanted to own.  This is easy to believe if we pick something simple like a MiniMoog, or a Jupiter 6, but the reality is that the Solaris has resources to be far more ambitious!

Let’s consider the legendary Yamaha CS-80 polysynth, which is perhaps the most desirable analog polysynth ever made.  Functional used copies sell for upwards of $20,000 if you can find one at all.  Maintenance is not cheap or easy.  The synth provided 8 notes of polyphony and full polyphonic aftertouch.  The Solaris can mimic the architecture and provide 10 voice polyphony, with polyAT (though you might need a Roli Seaboard to get the PolyAT going…).  Here’s the voice architecture of a CS-80 – Yamaha was kind enough to print it on the top of the instrument.

There are two identical voices that can be programmed, so in effect there are two of this signal chain to represent.  The Solaris does not perfectly re-create this, but it can get very close (it even includes ring-modulation in the Amplitude Modulation section!).  Of course, it’s modulation matrix is vastly more capable than the CS-80, so it is actually far more capable than the CS-80 in most respects.  Let’s see how we can lay this out in the Solaris, using the mixers to bring the Solaris components into the right order.

This layout recreates the modulation control present in the CS-80.  If you want access to the Ring Modulator in the Solaris, it is available in either Mixer.  The Ring Modulator is in the AM1/AM2 section of the synth (hit the MORE button on the global screen).  You then access the audio by selecting AM1 or AM2 as the input to one of the four mixer channels.  In most patches, I’d replace the Noise input with the AM1/AM2 input, but this is clearly flexible per voice and per patch. I highly recommend adding a bit of the Ring Modulation – maybe 5% strength, modulated by the wheel, and then mixed in at low volume, maybe 3-5 in the Mixers.  It really adds a nice subtle harmonic complexity that changes wonderfully with the wheel.


The Solaris has near infinite modulation possibilities beyond this, but this patching arrangement will allow the exploration of the core CS-80 sound palate. What I did is set this up, and then I saved it as a patch.  I don’t edit this patch, but use it as a template for other patches.

Clearly, this same approach can be taken toward other classic synths. If we can model a CS-80, Jupiter8’s and many others are all possible.  In fact, this is a great way to learn the Solaris.  Every component of the Solaris is more capable than the CS-80.  The oscillators are capable of digital wavetables, the filters have many different types compared to 12/24db HPF/LPF, the modulation matrix and control inputs are many times larger.  But the synth voice architecture is proven and will produce playable sounds at every turn.  The wonderful thing about doing this exercise on a Solaris is that you can start with a known, proven architecture, and then when you want more control, use the extra facilities or the Bowen to modulate the attack portion of the envelope with velocity, or use the rotors, etc.

I’ve never owned or played a real CS-80, and may never get to.  This post is not arguing that the Solaris is going to produce so authentic a sound that CS-80 ownership is rendered moot.  Instruments have a gestalt – including the Solaris – that isn’t going to be recreated on something else.  What this post does suggest is exploring the sound space that instrument was capable of making, and then using that as a point of departure to do things that the CS-80 was never capable of.  By replicating, and then exceeding the architecture of previous synths, it is possible to creatively explore new territory.