Many synths include some form of on board effects processing. Whether they’re multi-processor modular effects units on modern workstations or simple chorus or delays, effects processors of some kind or another are probably on board most of your synths.
You’ve probably also got a good selection of external (including plugin) effects too. And some of you might have wondered about which you should use. Internal or external? Sometimes the choice is down to convenience. Sometimes it’s what’s configured in the preset. Sometimes you’re after a sound that requires a little something special. There are plenty of reasons for choosing one or the other.
When I have to choose, I usually consider three factors:
Polyphony: Applying affects polyphonically (one instance for each note) can sometimes have a very different result than applying them to the mono/stereo mix of voices. It’s particularly noticeable for distortion. This only applies if your synth part is polyphonic, it makes no difference for monophonic synth parts.
Modulation: Applying effects using the internal synth effects can sometimes allow those effects parameters to be modulated by the synth’s envelopes, LFOs and other modulation sources.
Sound: Most synths have a limited selection of effects. These might be tuned specifically for the synth, but you’ll have to consider whether the sound is the one you want. You have a lot more flexibility in using external effects.
How do you choose your effects?