Install blepvco by entering the following commands in the terminal:
sudo apt update sudo apt install blepvco
LADSPA, minBLEP-based, hard-sync-capable oscillator plugins
A collection of LADSPA plugins containing three anti-aliased, minBLEP-based, hard-sync-capable oscillator plugins. The oscillators are intended to be used with modular synthesis systems, such as Alsa Modular Synth.