Don't mean to take the thread too OT, but I'd love to hear more about that surround sound processor.
I had a Yamaha DSP1 in the mid/late 80's and used it for all kinds of interesting stuff. As one of the first general outboard DSP boxes it suffered something of an identity crisis, being partly targeted at hifi ambience extraction and recreation, partly at early pre PLII era Dolby Surround, and partly at effects for musicians and mixing. It had four outputs which could be used to feed speakers placed in the upper corners of the room, and an accompanying 4 channel power amplifier. It didn't have much bit resolution and had a rather high noise floor, but the algorithms were very good for the time. I'd use it for music making mostly as a 4ch Lexicon type verb, 3d swirly phaser/flanger guitar and organ effects, and vocal chorusing/pitch-changing stuff. It was great fun at parties, switching roles between eye-opening unexpected mind-expansion of whatever music was playing (it was predecessor to the later ubiquitous and generally terrible "hall" preset modes built-in to home theater receivers, except way better implemented) which would morph into panning and swirling our own jams all around the room. After a day's field trip out to the cow pastures, later totally displaced by housing developments, we'd come home, boil up some tea, open all the windows and let the music diffuse out into the thick air of a warm summer night. Good times.
As I recall, the modulated pitch-changer in combination with a cheap DAK digital delay unit in a loop-back arrangement was capable of forming a vortex that could cause the floor to dissolve away revealing a bottomless cavern reaching all the way down to the center of the earth. It took a fine hand on the controls to ease intrepid travelers safely back to the surface without subjecting them to too much psychic-g-force.
Topic: TSKB: Speaker restoration (Read 10479 times)