Take the default buffer size at first. If you do not plan to use MIDI, it will probably be fine. If you do plan to use MIDI, use the output options and try to set it as low as possible. Many systems allow the minimum 5 millisecond buffer size, which gives excellent MIDI performance!
Try the "New" button for creating new presets.
The GAIN response simulates analog "soft" clipping. If you use it to adjust listening volume, you will also be affecting your preset. Use the Windows mixer settings instead.
MIDI does not work unless you turn on the MIDI window.
Everything in SimSynth syncs to tempo. There are 500 "clocks" per beat. For example, 1/8th note is 250 clocks, 1/16th is 125 clocks, etc.
Powerful sound doesn't mean a lot of oscillators, detune, and +1, +2. In fact, sometimes that leads to something called phase cancellation and can actually make the sound wimpier.
If you want a loud sound you may just need to turn up the volume on your system. It's a common mistake to keep bumping gain levels, and overdriving a preset, because it seems like it needs to be louder.
EMPH is a type of feedback, and makes the filters louder. This can lead to overdrive clipping, and noise. Watch the OUT level in the SVF when using a lot of EMPH, and maybe turn it down to compensate, (then you can boost the GAIN if you need to).
1.x style is not recommended except for 1.x preset compatibility and special effects. It generally makes the filter response worse.
It often sounds better not to set the DELAY value to the exact timing you want, even though you want it to sync. For example 250 clocks is a 1/8 note, but 249 or 251 will make the echo more audible, and mix better with the dry sound.
AMP boost in the riff can cause clipping pops if set too high. This is easy to forget, and people have nearly given up on presets because they can't find the source of the popping!
Don't forget to pay attention to the ADJ setting when you change oscillator shapes.
