The Sputnik Dual Oscillator is their take on a classic complex oscillator design pioneered by Don Buchla. It is best to think of a dual oscillator as one part modulator and one part carrier.
In the east coast (or moog style) philosophy of synthesis we take a harmonically rich waveform like a saw or a square wave and then use a filter to remove frequencies or alter harmonic content. In opposition to this in the west coast method we take a simple waveform like a sine and then use a process of modulation and wave folding to create a harmonically rich waveform. You can even think of a wave folder as the opposite of a filter.
There are many other things that set the west coast way of working apart from the east coast, but we won't go down that rabbit hole just yet. And in my opinion it is neither here nor there anymore, with a good eurorack setup you can mix and match as you please.
We have two Generators which each provide 3 different outputs. Each Generator can respond to 1v/Oct input but also has an array of different CV ins; including FM in, Bipolar CV in and sync. Generator 1 however can also be set to go down into the LFO range which is extremely useful when using it as a modulation source. It also has 3 different switchable waveforms; triangle, saw tooth and square. No PWM, but then thats more of an east coast thing.
Generator 1 is generally thought of as our modulator and Generator 2 is our carrier. Between the two Generators we have a Modulation bus that can give 3 different modulation types for modulating Generator 2 with Generator 1; Frequency Modulation, Amplitude Modulation and Timbre Modulation.
The second Generator has a wave folder on its output, we listen to this by using the final output of Generator 2. We have a Timbre section and a Harmonics section. Timbre is essentially the amount of wave folding and the Order of Harmonics will alter the harmonic content from wave folding to more standard wave shaping, adjusting the odd and even control will change the tone of the outputted waveform, giving qualities of saw and square waves.
Throughout the process of reviewing this oscillator I have been astounded by the sound quality and the range of tones available. It can produce such a massive variety of sounds with the careful adjustment of a few parameters and/or the introduction of CV sources, or internal modulation. it can be very sweet and subtle and then with the adjustments of a few key parameters can go into insane and brutal territory.
At £425 you will not be disappointed, and if you think that that is expensive then just look at the other complex/dual oscillators on the market and then reconsider your judgement. The build quality does reflect this price point slightly, with the use of obviously cheaper switches and plastic shafted pots, but on the whole I have not found any of this to be an issue for me.