For anybody not familiar with the concept: A guitar effects pedal — often called a stomp box, just a little disparagingly — is a sound processor that is placed on the floor in front of the guitar placing person. The guitar is connected, via cable usually, to the processor: You plug it in on the input side. You connect the output with even more pedals or with your guitar amp.
The little box changes the signal in ways that may be predictable or not. The most widely and well-know effect for electrical guitar is distortion. That’s the one that gives the electric guitar its specific vroooom and roaaaar sound.
There are other types: Phaser, Chorus, Reverb, Delay, … They are all great.
Really Weird Ones
Of course there are real life pedals that can produce really weird and at times unpredictable sounds. One of the most sci-fi like pedals that I own is the Ibanez Digital Modulation Delay. It is able to produce delay trails that swirl away into space.
This seems to be a rare piece of gear and one I will never sell. It must be from the 1985 Master Series (L Series) which is overshadowed online by the later Power Series versions, DML10 and DML20. However, according to the original Ibanez DML Manual, it features advanced specifications for its time.
You can find some details and even a manual as PDF file here: Tonehome > Ibanez DML Digital Modulation Delay
The RockBoard PedalPedia also has some information on it: Ibanez DML Digital Modulation Delay on the RockBoard PedalPedia

A modern classic and regular nominee for weirdest pedal available seems to be the Rainbow machine by EarthQuaker Devices. It is a polyphonic pitch-shifting synthesiser – sounds like just the thing you need to make being on stage comfortable.
You can get it here, and there are sound samples available: Rainbow Machine on www.thomannmusic.com












