Daniel,
THIS GUY got couple of 'mad' recordings ... scroll down...see song description...on the bottom of the page couple mp3s ( StratoMorphisis and The Old Castle ...well, this is sorta' experimental stuff

..but you get some idea about how SE could "sound". BTW, while you're there you can 'get a feel' about how Teac 144 Portastudio 'sounds in action'

heh heh
To say shortly - Space Echo sounds like tape-delay

...well, also a bit more 'complex' depending on mode selection and feedback level.
You really should just try to experiment yourself with what ever R-t-R machine with record and play heads you have.... set the output to 'tape'(repro) and send it/patch output back into the mixer (adjust level) - send to deck's input - play something and record ..have fun

you get the idea about tape-delay sound. Nothing is like it. BTW the tape itself and all the things related to it and all the "inperfections" of the tape is a part of the effect.... so there.
I have posted some direct links to mp3 samples of my 'cassette tape delay' machine , while I was just experimenting and playing some synth sounds from JV-1080 synth through it... it is
HERE at DUB discussion board, scroll down ...the samples in the later post there. Again...this is not Roland, but so you can get some taste of tape delay if you wish.
Also Roland SE units are mad-expansive nowdays... around 500 bucks if in good shape ..grrrrrrrrrrrr. I'd say using R-To-R machine with three heads and speed control is one of the alternative ways to get tape-delay/echo effect.
/later