Before digital advancements simplified sound processing, engineers dealt with delays using bulky tape echo machines or natural echoes from reflective surfaces. In the late 1960s, engineers Sangster and Teer innovated with the bucket brigade delay (BBD), a system that splits audio into samples passed through a transistor-capacitor chain. This method mimics how sound travels, delaying the output signal relative to the input. Throughout building this module, we will reverse engineer the architecture of a classic bucket brigade delay, recreate a bare-bones version on the breadboard – and then use a proper BBD chip to implement a simple audio delay effect.

We – Erica Synths and Moritz Klein – have developed a series of educational DIY kits under the brand name mki x es.EDU with one specific goal in mind: to teach people with little-to-no prior experience how to design analog synthesizer circuits from scratch. What you’ll find in the box is not simply meant to be soldered together and then disappear in your rack. Instead, we want to take you through the circuit design process step by step, explaining every choice we’ve made and how it impacts the finished module. 

NB! All kits in this series are simple and come with extensive user manuals which can be downloaded separately, therefore we will not provide customer support in case your DIY build fails to function or similar.