FL Studio Guru | Interpolation, Sampler Channels & Aliasing
Other causes of problems - • FL Studio Guru | Media Player & Soundcard ...
So what about other plugins?
VST, Dx & FL Native plugins (synths & samplers) may or may not have their own internal interpolation settings (sometimes called over-sampling).
If you check Sytrus for example you will see it has its own Live (Draft) and Render settings. All good plugins interpolate/oversample or whatever, but some just don't show these settings to the user.
To make sure plugins DO put their best foot forward when rendering, make sure the switch "HQ for all plugins" is on in the Render dialog and the Wrapper setting "Notify about rendering mode" is also on.
Enjoy!