Bucket Brigade Delay

This is an emulation of a vintage analogue delay unit that used a 'bucket brigade device' (BBD) chip for the delay. This was a discrete analogue time delay line where the stored analogue signal was moved along a series of capacitance sections one step at each clock cycle, similar to a line of people passing buckets of water.

Unlike the analogue equivalent, the GLD Bucket Brigade benefits from long delay lines (up to 2.7 seconds) but maintains the signal degradation expected from such a device.  The level of signal degradation is switchable via a ‘DIST’ (distortion) control which switches between different nonlinearities in the feedback path. Note that even in its cleanest mode the Bucket Brigade delay will degrade and band limit the signal.

The delay has two modes of operation:

BPM mode - The delay interval is determined by the selected beats per minute and corresponding note value.  Standard, dotted and triplet intervals are selectable via the interval selection wheel from whole to 16th intervals.

MS mode - The delay interval is set directly in milliseconds.  The stereo beat delay can also be locked to the global tap tempo.  There are controls for both input and feedback filters, with the latter having individual slope parameters.

Note  The Bucket Brigade Delay can also be locked to the global tap tempo. Global rate can be manually entered or tapped in using the screen of any delay FX locked to global tap tempo, or by tapping a SoftKey assigned as Global Tap Tempo.

Controls:

Input filter HP frequency – Sets the frequency of the high-pass filter on the input to the delay. This cuts low frequencies.

Input filter LP frequency – Sets the frequency of the low pass filter on the input to the delay. This cuts high frequencies.

Width – Controls the stereo imaging of the delay unit, from focussed mono sounding to panned wide stereo delays.

BPM/MS mode – Switches between Beats Per Minute and Milliseconds mode.  In BPM mode the BPM and note selection wheels are displayed allowing delay times to be set as an interval of a selected BPM.

BPM window (in BPM mode)– Touch and use the rotary to select the BPM that the note values are synchronised from.  

Interval Selection Wheel – Determines the delay time to be set in synchronisation with the chosen BPM.  The values range from whole dotted intervals to 16th triplet notes.  When an interval is not available due to the BPM being too low, the interval will grey out and not be selectable.  

MS time window (in MS mode) – Allows the delay time to be set directly in milliseconds.

Link – Links the left and right delay times.

Local / Global Tap – Locks the delay time to the global tap tempo allowing global synchronisation across the console or locally to this effect unit.

Fractional / Notation display – Choose to display either fractions or notation representation of the selected interval on the selection wheel.

Low Damp Filter frequency – Selects the frequency of the low damp filter in the feedback path of the delay unit.

High Damp Filter frequency – Selects the frequency of the high damp filter in the feedback path of the delay unit.

Feedback filter slope – Selects the slope of the feedback filter. To filter more or less of the feedback path.

Feedback – Controls the amount of the feedback in the delay. A larger amount increases the number of audible repeats.

Dist – Changes the distortion characteristic of the feedback path allowing for more or less signal degradation.