Kurzweil k2500 User Guide

FXAlg #130: Complex Echo

Algorithm Reference-33

FXAlg #130: Complex Echo

Multitap delay line effect, consisting of 6 independent output taps

and 4 independent feedback taps

Allocation Units: 1

Complex Echo is an elaborate delay line with three independent output taps per channel, two independent feedback
taps per channel, equal-power output tap panning, feedback diffuser, and high frequency damping. Each channel
has three output taps which can each be delayed up to 2600ms (2.6 sec) then panned at the output. Feedback taps
can also be delayed up to 2600ms, but both feedback channels do slightly different things. Feedback line 1 feeds the
signal back to the delay input of the same channel, while feedback line 2 feeds the signal back to the opposite
channelÑit can be considered Òping-pongÓ feedback. Relative levels for each feedback line can be set with the
ÒFB2/FB1>FBÓ control where 0% only allows FB1 to be used, and 100% only allows FB2 to be used.

The diffuser sits at the beginning of the delay line, and consists of three controls. Separate left and right Diff Dly
parameters control the length that a signal is smeared from 0 to 100ms as it passes through these diffusers. Diff Amt
adjusts the smearing intensity. Short diffuser delays can diffuse the sound while large delays can drastically alter
the spectral flavor. Setting all three diffuser parameters to 0 will disable the diffuser.

Also at the input to the delays are 1-pole (6dB/oct) lowpass filters controlled by the HF Damping parameter.

Signal flow of Complex Echo

Delay

Pan

Delay

L Input

R Input

L Output

R Output

Feedback

FB2/FB1 > FB

FB1

FB2

FB1

L Tap Levels

R Tap Levels

Out Gains

Diffuser

Blend