Efficient emulation of tape-like delay modulation behavior

Vadim Zavalishin; Julian Parker
DAFx-2018 - Aveiro
A significant part of the appeal of tape-based delay effects is the manner in which the pitch of their output responds to changes in delay-time. Straightforward approaches to implementation of delays with tape-like modulation behavior result in algorithms with time complexity proportional to the tape speed, leading to noticeable increases of CPU load at smaller delay times. We propose a method which has constant time complexity, except during tape speedup transitions, where the complexity grows logarithmically, or, if proper antialiasing is desired, linearly with respect to the speedup factor.