Expert Sleepers offers a collection of Audio Units plug-ins that includes five delay-based effects — Augustus Loop, Ping Pong Delay, Multitap Delay, Buffer Delay, and Phaser — and two virtual instruments, Additive Synth and Crossfade Loop Synth. All but one of the plug-ins are freeware and sport basic graphical user interfaces (GUIs) to perform straightforward functions. All are easy to operate and CPU efficient, and all perform their DSP functions well. None of them include any presets.
Augustus Loop (Mac, $20) is the first Expert Sleepers plug-in with a real GUI, and it's also the most sophisticated. It combines long delays (maximum of one hour) with four feedback taps. Each tap has individual time settings (as a percentage of the overall delay time) and level controls for left-to-left, left-to-right, right-to-left, and right-to-right delay. Like tape delays of the past, it has sliders for real-time change of pitch (virtual tape speed) and delay time (virtual spacing between the tape heads). The signal path ends in a resonant multimode filter with saturation and a dedicated LFO. An LFO is also provided for pitch. Handy Tap and Hold Record buttons clear the buffer, record a loop, and set the delay time to the loop length in one step. Tap and Hold Tempo buttons set just the delay time. Loop Freeze and Reverse buttons round out the complement of tape-delay-like controls. Augustus Loop is a terrific tape-delay emulator that is easily worth the price. See the clip on EM's Web site for an example of a guitar lick mangled by Augustus Loop (see Web Clip 1).
Crossfade Loop Synth (Mac, free) is a looping sample player. Its author, Andrew Ostler, said he wanted a program that would do just what his old Roland S330 would do. Crossfade Loop Synth allows you to load one audio file at a time and trigger it from a MIDI keyboard. The sample can be played polyphonically and is mapped across the entire MIDI key range. You can choose the root note and fine-tune the pitch. Loop playback settings are all relative to the total loop length (range 0 to 1) and include Start Offset, Loop Start, Loop End, and Crossfade. Having relative settings for those parameters makes it easy to control the looping of even poorly trimmed loop files. With enough crossfade time, you can seamlessly loop any material. At the end of the signal path is a resonant multimode filter with an attack-release (AR) envelope and another AR envelope for amplitude. For one-shot situations, you can disable looping.
The five remaining plug-ins (Mac, free) have generic GUIs with labeled blue-button sliders and accompanying displays for numeric data entry. Additive Synth has controls for the level of the first eight harmonics, the attack and release of the amplitude envelope, and overall level. Ping Pong Delay is a feedback delay line with a range of 1 millisecond to 2 seconds. The initial pan setting also controls the stereo spread of the pings, and a resonant multimode filter is available at the output. Multitap Delay features four taps with individual delay-time, pan, and feedback controls. Again, there is a multimode filter at the output and an overall feedback control.
Buffer Delay is a sample-accurate utility delay you can use to compensate for plug-in latency. It has sliders for setting the delay time in 1 and 128 sample increments. It can also be used as a send effect to produce fixed phase-cancellation effects. Phaser is a cascade of all-pass delays with controls for Depth (wet-dry mix), Intensity (number of all-pass delays), Spread (relative phase of the left and right stereo channels), and Sweep (frequency range). You can download the Expert Sleepers plug-ins from www.expertsleepers.co.uk.