Fast melody sounds smeared? Fix the synth envelope

Check the amp envelope. A pad envelope has a slow attack and a long release, so fast notes fade in late and overlap into a smear. For fast melodies use a pluck envelope: attack at 0, a short decay (100 to 300 ms), sustain at 0 and a short release. Every note starts instantly and gets out of the way of the next one.

How to do it

1. Open your synth's amp envelope (ADSR).
2. Set attack to 0 so every note starts right away.
3. Set sustain to 0 and decay to about 100 to 300 ms.
4. Set release short, about the same as the decay.
5. Add a little reverb or delay if it sounds too dry.

Why it works

The envelope decides how each note starts and ends. Slow envelopes suit slow chords. Fast notes need fast envelopes, or they pile up on top of each other.