Hi @Klaustrophil, it sounds like MODEP is using an older version of the Bollie Delay. This was an issue that has been solved in the newest version of the plugin. The previous version clears the delay buffer when the tempo is changed. Due to the fact that a MIDI clock is has a lot of small tempo fluctuations, the buffer is getting cleared constantly, this results in having no sound. The newer version of the Bollie Delay does work well with an external MIDI clock.