Doubling and Modulation
The term “doubling” refers to the process of using a subtle delay to thicken your sound. To get a doubling effect, set Time between 50 and 100 ms, Feedback for minimal repeats (one or two), and Level all the way up. Because the repeat happens so quickly, it creates the illusion of another guitar playing in unison with the original signal rather than sounding like an echo. If you use a lower delay time (20 to 50 ms), you can also get pseudo chorusing and flanging sounds.
Slapback is a single short repeat similar to a tape slap (the time delay between the record and play heads in an analog tape recorder), and it is most often heard in rockabilly and country. To achieve a slapback effect, keep the Time short (between 80–140 ms), Feedback at 0 (so you only get one repeat), and Level at about 50 percent.
A reverb-type effect can be achieved by modifying some of the settings used for slapback. Set the Time between 100 and 200 ms, Feedback for about 5 repeats, and Level at about 50 percent.
Most delay pedals do not have precise delay time readings on their knob panels. This isn’t a crucial issue when you’re using shorter delay times or when precise timing of the repeats is not integral to the performance. However, if you’re playing to a fixed beat source (say, a band or rhythm track) with a delay time of more than 200 ms and a fairly high Level setting that gives the repeats a distinct note, it will sound best if you dial in a precise delay time that matches the tempo of the band or rhythm track. Otherwise, the repeats will be out of time against the underlying beat. If your music is delay based, delay pedals such as the Providence DLY-4 Chrono Delay (street $449), TC Electronic ND-1 Nova Delay (street $259), and Strymon Timeline (street $449)—all of which feature LED readouts of the delay time—are worth considering.
Many delay pedals from the last decade or so offer a happy middle ground with tap-tempo functionality (some designs require using an aftermarket external footswitch to access this). If you’re familiar with the term but aren’t quite sure exactly how it works, here’s the scoop: Though many players don’t know the exact tempo they need in terms of beats per minute (bpm), most have an innate sense of the tempo they wish to play at, so tapping it out on a delay pedal’s tap-tempo footswitch is an easy way to get the sort of tempo matching we’ve been talking about. If your delay doesn’t have tap-tempo functionality, or if you want a formulaic approach to calculating the delay time, see the “Calculating MSfrom BPM” sidebar.
Newer digital delays such as the Providence DLy-4 Chrono Delay, TC Electronic ND-1 Nova Delay, and Strymon Timeline feature exact millisecond readouts for players who need very precise delays for tempo-matching purposes.