sp-404 outs to recording device ins, recording device headphone outs to sp-404 ins, both armed to record, with vinyl sim ctrl 1 and 3 all the way turntup. weird delay/ sine wave whoa.

. double post

tried this out a couple of days ago, recording into minidisc with the outs of connected back to the ins of the 404, and with the internal mic open while playing the pads - lots of nice feedback (not out of control)... fun to play with different fx in this way, tap on the box, etc... noiseeee

ok check this out. completely out of context but similar in style
take two cell phones (not sure about the new smart phones...-_-) and have them both in the same range of each other (like one foot or less)
have one call the other and have both on speakerphone
once connected feedback will occur... speak into them and move them in and out of range of eachother for crazy delay effects
experiment... id love to hear about similar discoveries
maybe filtered thru what you described? on a vacation...no sp's to try with at the moment...