has anybody used these before in there four track machines...i've recently pulled out a couple of my old four tracks (424mkII, 424mkIII, mt4x) and have been having a blast making cassettes full of backwards noises, variable tempo mixdowns and whatnot...then, today, i found a thing called an endless tape loop cassette...they can be bought with 1 minute up to about 6 minutes of tape loop...i remember reading about using old answering machine tapes but was convinced that they didn't work to well in a four track machine...has anybody used these before...the ones i saw for sale seem to be of better quality then the answering machine tapes...i think i might be fun to mess around with...i mean, i've done tape loops before on my tascam 38 but this seems like it would be alot funner and easier to mess around with...anyone got any stories they want to share about using these...