Delay & Modulated Delay

Question 1

What is delay in audio processing?

Answer 1

– A time-based effect that plays back delayed duplicates of a signal to create repeats.
– Integral to many effects, e.g., modulation and reverb.
– Used for doubling, echo, rhythmic effects, placing sounds in space, and enhancing stereo position.

Question 2

What is the delay time parameter?

Answer 2

– The gap between each repeat.
– Can be tempo-synced in DAWs.

Question 3

What is feedback in a delay effect?

Answer 3

– Part of the delayed signal is fed back into the input.
– 0% feedback = one echo; 100% feedback = endless repeats.

Question 4

How can you alter the stereo placement of delay?

Answer 4

– Use the pan control to place delay/taps left or right.
– Apply filtering to change frequency content of repeats.

Question 5

What does the dry/wet (mix) control do?

Answer 5

– Adjusts the volume of the delayed signal relative to the original (dry) signal.

Question 6

Describe analogue tape delay.

Answer 6

– Records signal onto a tape loop via a record head and plays it back with playback heads.
– Multiple playback heads can create multiple echoes.
– Tape gradually degrades, losing high frequencies (“warm” sound).
– Delay time adjusted by moving playback heads or changing tape speed.

Question 7

What is a bucket brigade delay?

Answer 7

– Analogue technology used in 1970s guitar pedals.
– Uses capacitors to hold charge, passing it along a chain of stages.
– Longer delay = more degradation and noisier output.

Question 8

How does digital delay work?

Answer 8

– Stores the signal in memory, allowing manipulation.
– Hardware digital delays popular in late 1970s–80s; digital plugins from late 1990s.

Question 9

What is slapback delay?

Answer 9

– Single, quick repeat (80–150ms) at roughly the same volume as the original signal.
– Popularised by early rock and roll artists like Elvis Presley.

Question 10

What is ping pong delay?

Answer 10

– Delayed signal bounces between left and right channels.

Question 11

What is multitap delay?

Answer 11

– Digital delay creating complex rhythmic patterns with multiple independent delays.

Question 12

What is sample delay?

Answer 12

– Delays one side of the stereo field by a few samples (used for artificial double tracking).

Question 13

What is reverse delay?

Answer 13

– Delays the signal, then reverses the delayed signal so it plays backward.

Question 14

Historical use of delay

Answer 14

– 1940s: experimental tape echoes.
– 1960s: psychedelic music, guitar solos.
– 1970s: progressive rock, bucket brigade pedals.
– 1980s: digital delays for precise control.
– 1990s: EDM uses rhythmic stereo effects (ping pong).
– Ambient, shoegaze, grunge, alternative rock: ethereal textures, lo-fi, heavy distortion/feedback.

Question 15

Practical uses of delay in modern production

Answer 15

– Thicken vocals (doubling effect).
– Add echo for depth.
– Align tracks recorded separately to fix phase issues.
– Create rhythmic patterns and movement (e.g., ping pong).

Question 16

What is modulated delay?

Answer 16

– Delay where the delay time is periodically modulated by an LFO (low-frequency oscillator).
– Creates effects like flanger, chorus, vibrato.

Question 17

What is an LFO?

Answer 17

– Low-frequency oscillator; controls a parameter over time (e.g., delay time).

Question 18

How is comb filtering created in modulated delay?

Answer 18

– Slightly delayed signal combines with dry signal, causing destructive interference at some frequencies (flanger effect).

Question 19

What are key modulated delay parameters?

Answer 19

– Rate: Speed of modulation; can be synced to DAW note value or set in Hz.
– Depth: Amount by which the delay time is modulated.
– Feedback: Amount of wet signal fed back to the input, affecting tonal color and sweep.
– Mix: Dry/wet balance.

Question 20

What is a chorus effect?

Answer 20

– Delays a copy of the original signal by a small, varying amount using an LFO.
– Dry + delayed signal simulates multiple performers (slight pitch/timing differences).
– Longer delay than flanger → perceived layering rather than comb filtering.
– Common on clean guitar, fretless bass, synth pads.

Question 21

How does chorus depth and rate affect the sound?

Answer 21

– Low depth/rate: subtle sense of life or movement.
– High depth/rate: dramatic “bubbling” or “underwater” effect.

Question 22

What is a flanger?

Answer 22

– Similar to chorus but with shorter delay times → comb filtering effect (“whooshiness”).
– Feedback can create pitched, sweeping sounds.
– Extreme settings → jet-plane effect; often used with distorted guitar.

Question 23

How is a phaser different from a flanger?

Answer 23

– Phaser is a filtering effect; wet signal’s phase is altered rather than delay time.
– Creates subtle cancellation effects when combined with dry signal.
– Can emulate “rotary” sounds like Leslie speakers.

Question 24

Historical context of modulation effects

Answer 24

– 1960s: Studio-created using two synchronized tape recorders (slightly delayed second track → artificial double tracking).
– Leslie speakers for Hammond organs created Doppler effect (rotary effect → combination of chorus, vibrato, tremolo).
– 1970s–80s: Analog modulation pedals for guitar and keyboards.
– 1990s onward: DAWs and plugins allow precise control and emulation.

Question 25

Practical uses of modulated delay

Answer 25

– Thicken vocals or instruments. – Create movement and life in static tracks. – Add ethereal, shimmering, or dramatic effects depending on depth/rate/feedback. – Subtle use: gentle detuning or slight vibrato. – Extreme use: underwater, jet-plane, or swirling effects.