LFO Delay Fbk is a modulated delay line with a feedback path, extending the LFO Delay for resonant flanging and repeating echoes. Delay, Rate, Depth and Skew control the base delay and its LFO sweep, Mix blends the dry and delayed signals, Feedback (0 to 1) returns the delayed output to the input, and Output trims the level in dB. The Modulation selector chooses the LFO waveform — Sine, Triangular, Log (symmetric), Square, Log (asymmetric), Random (uniform) and Random (telegraph). It works in mono and stereo.
The input, summed with the previous delayed output scaled by the Feedback amount, is written into a circular buffer and read back at an LFO-swept, linearly interpolated tap; the result is mixed with the dry signal and scaled by the output gain. It processes one sample-frame per tick, in step with WaveWarp's sample-per-sample engine.