Before the digital delay there was the tape echo machine and it was cheap enough that every band (and in some cases guitar players) had one. The problem was that most of the models available at the time weren’t exactly “studio-ready,” so they rarely made it into the average studio in the U.S. Then came the Roland Space Echo in 1974 and it was deemed professional enough (even though it didn’t have balanced in and out until much later) that they began to pop up on recordings everywhere.
Although the 2 track studio tape machines of the 70s provided better fidelity, they lacked the versatility of the Space Echo and were a great deal more expensive. That’s why it was always nice to have an RE-201 around, at least until the inexpensive digital delay unit came along to replace it. The model RE-201 and all the versions after it were actually based on a long tape loop, which wore out relatively easily, but that’s what gave it the sound that we still try to emulate today.
A rather remarkable website has an interactive look at not only all the controls on the Space Echo, but also a peek inside to see what makes it tick. Plus there are also a few audio samples as well. Be aware that the site will take up a lot of browser’s resources, but it’s still pretty cool.