Beyond these obvious considerations, if you want to sync your delays to song tempo you’ll need tap-tempo. If you want to route your un-delayed sound to one amp, and the delayed sound to another, you’ll need two outputs. If you want to use a foot controller to tweak parameters on the fly, you’ll need an expression pedal jack. And if you want to patch additional effects into your delay’s feedback path, you’ll need an effects loop. Finally, one of the coolest effects produced by vintage tape-based and analog delays is self-oscillation, where you crank up the repeat knob until the unit starts generating sound by itself, and then change the delay time to create a sound that simulates a spaceship taking off.
The nine pedals reviewed here were tested using various guitars played through an ultra-clean Fender Twin Reverb and a Rivera Chubster 40, and were then given the “white glove” test by routing the Rivera’s speaker output to a Palmer PGA-04 direct recording device and a MOTU 838mkII, and monitoring sound quality through AKG K-240 headphones.