In the world of
electronics, this refers to an
analog semiconductor chip that consists primarily of a
capacitor "ladder" which passes an
analog signal from stage to stage in
synchronization with an external
clock signal. Bucket brigade chips are used primarily to create
analog delay lines which can be used in
audio applications such as
guitar effects like
flanging,
delay and
chorus.
Unfortunately, the last of these chips (the MNXXXX series from Panasonic) went out of production in 1999, which means no more analog delay effects can be manufactured. Previous incarnations are currently in very short supply and are highly prized, hence expensive.