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"some of the highlights of this synth:
Oscillators
These 3 super-precise oscillators don't drift unless you ask them to. By injecting a little modulation, you can get some wonderful vintage warmth. Or you can keep the modern stability. They have a wide frequency range. When you use one oscillator to FM another, you get some truly musical effects. Oscillator 1 doubles as a voltage-controllable low frequency oscillator.

LFO
One of the coolest, and least-known features of the LFO is the doubling of speed that happens in the Sawtooth and Ramp modes. With the voltage control offered, you can use it as an audio VCO. The LFO also offers a couple cool gated modes.

Filters
For me, the most attractive aspect of the synth was the incredible filter section. The Lowpass filter is switchable between 4-pole (-24db) and 6-pole (-36db) modes, as well as a band-pass mode. The Multimode filter is switchable between 2, 4, and 6 poles, and Highpass, Bandpass, and Lowpass modes. (The Bandpass actually uses 1, 2, and 3 poles.)

You can use these filters in parallel or series for some incredible sound-shaping. With all the different filter topologies offered, the subtractive synthesis capabilities of the S1Mk2 are nearly unparalled among semi-modular synths. It is truly amazing to be able to select between buzzy 2-pole and deep-bite 6 pole modes. And when you run them in series, you can get up to 12 pole mode (-72 db!). A truly deadly filter bite! Couple that with the hyper-snappy envelopes and you have a synth with some of the deadliest teeth you will ever encounter.
Each filter has a 5-input mixer. Each filter can take one external signal.
Envelopes
Speaking of the envelopes, the two envelopes on this synth are incredible. They are super-fast, excellent for percussion sounds. With the fast speeds, you are able to get sounds with this synth impossible in vintage instruments. However, these envelopes are easily capable of the slower times of older synths. Also, they both include a Delay stage. This is a pause between the gate-on and the Attack stage. When both envelopes are used together, and one is delayed, pseudo-delay effects are possible.
Both of the identical DADSR envelopes are completely controllable. They have voltage control inputs for each stage. This allows you to mimic the acoustic properties of real-world instruments. There is a switch for linear/exponential modes. There are positive and negative outputs.
I should mention a couple issues:
There is some slight bleedthrough of oscillators 1 and 2 into mixer outputs 1 and 2, respectively. Not noticeable at typical levels, really only if you are using the mixer as your main output..."
SN S1mk2-023