What is a Delay?
A delay is an audio effect which plays back a part of an audio sample again after a period of time.
During the late 50s - 60s everybody used tape delays. Early models used preamp tube circuitry that added some 'warmth' to the sound.
On reel-to-reel magnetic recording systems it was easy to achieve a delay effect by shortening or lengthening the loop of tape and adjusting the read and write heads.
Tape in general has warm and natural sounding delay repeats, which are set by distance changes between the record and playback heads and returning the sound back into the record head multiple times to generate multiple delays.
Tape delay can handle long delay times and it creates a musical effect through “wow & flutter” from the tape itself which is why a lot of people tend to prefer tape
Famous hardware found in studios: Echoplex, Boss RE series, Fulltone TTE, Watkins Copicat
Tape delays are 100% analog but most of the time you will see a difference between tape and analog when listing delays. Analog delays make use of capacitors to store and move an input signal along a line of capacitors. No tape needed. The sound will then be played back the desired number of times. The advantages over tape are much lower costs, more durable construction, and a smaller footprint. Spinning magnetic discs or a rotating magnetic drum were used inside this gear. Analoge delays show a treble loss which degrades with each repeat. This effect gives analog delays their warm sound, and a more natural sound.
Solid state comes up with a bucket brigade delay in the 70s as a mainstream alternative to tape echo.
Nowadays you see them everywhere and every homestudio should have a magazin of useful delay plugins or digital hardware.
The first available digital delay effects in the late 1970s (First was made in 1976 I think) and 1980s were only available in big, expensive rack mounted units which gave this time music a special character.
The first digital delay build in a pedal was the Boss DD-2 in1984. The big rack mounted delay units from that time evolved fast into digital reverb units and multieffects units capable of more sophisticated effects than pure delay, such as reverb and Audio timescale-pitch modification effects.
Digital delay systems samples the input signal through an AD converter, after which the signal is processed and stored into a storage buffer. Now you as user can play back the stored signal due to set up parameters. The processed signal can be mixed with the original dry audio to get the effects you like.
Most systems today have filters and effect mix abilities. Time, onset, level, reverse, pitch and much more of the processed signal can be adjusted in relation to the unmodified audio
Lexicon, Roland, TC Electronic are 3 of the big names you should remember when it comes to digital reverbs.
When to use what?
Digital delays cut through the mix much better and analog has a natural and warm sound.
They cover different aspects and needs.
For most people the basic difference between analog and digital delay is the clarity of the delayed sound. Digital delays make the repeated sound more like the original signal. Analog delays aren't as clear as they cut of the highs very fast. The signal gets more distorted and more dark with each repetition. Which one you like more, and for what application it is better, is a matter of taste and preference. I like analog delays a lot on ambience and urban sounds. Digital delay have a rich, clear quality to them which some people like, some people don't.
How to use a delay?
First lets deal with some parameters and see what they stand for.
Mix/Level - Controls the effected signal and mix it with the dry (unaffected) signal. 100% wet means only processed signal comes through and no original signal anymore.
Feedback - More feedback means more repeats. Sometimes this is labeled as percentage, db or ms. Is this set to 0 or none, it means it is only 1 time delay.
Time - Delays can be set up to notes (1/2, 1/4, 1/8, 1/16, 1/32, ...), can
be dotted or tripled and for sure they can be set to any ms you like.
Some delay units allows to tap the tempo
Type - On some units, plugins or pedals you can choose from different delay modes like classic and modern delay or clean, saturated, reverse delay, pitched delay, tape delay, dual delay, ping pong delay etc...
Rate/Modulation - Delays comes wigth a 'chorus' effect sometimes where you can set up the mod rate on your delays. You will end up detuning the repeated audio to give it a more distinct or vanished sound.
Some Tips and Tricks while working with delays:
Always sync to session tempo
when working with note delay.
If you have, set up some saturation or distortion effect before or after the delay.
Cut of the high ends and low ends. (Try filtering everything under 500 Hz and above 9000 Hz for example)
Wide up the stereo by using different delay times right and left. Pan a send full to the site or just set up two different parameters in a stereo delay plugin. For example try left 1/8 and right 1/16. Or both sites with 1/4 but different length time or a few ms offset on one site. Try the swing feature provided by some plugins on only one site.
With a vst/au 'tape delay' plugin, try to set your delay time to 0 ms for a bit of that tape saturation sound on your track.
Always remember how to calculate your delay times: 60000ms/bpm=X ms/bar
When programming drums, set up a 1/4 Hi-hat or shaker and use two different delays left and right to transform it into a nice 1/16 or 1/32 groove.
Create ambience by using an 1/8 note repeat on one side and a 1/4 note on the other. Do a left to right cross feed to add more stereo to it.
You can hilite parts of your song by just bypass all delay on one phrase or bridge to let it set back in right after to produce a nice air-wide effect.
Make extensive use of parameter automation. Try to automate everything: amounts of repeat, filter frequency, delay times, dry/wet balance or delay bypass and you will give 'live' to your mixes and songs.
By programming the delay times while a sound is playing, you can get some weird pitch effects if you set the delay to fast automated changes.
If you get too much phasing or masking effects, try dotted notes for your delay time.
Pitch is a great effect to create some weird spaced out delay effects. Start with a 1/4 delay on an empty songpart and play with pitch automation on the delayed part.
Route other effects to your delay return channel. Try Chorus, Flanger or other modulation plugins.