Opposite polarities on each channel
Posted by: Beachcomber on 07 July 2018
Years ago (1970s) there was some discussion about swapping +ve and -ve on one channel input of a power amp, and swapping the speaker +ve and -ve on that same channel. The idea was that there would be less demand on the power supply - so if both channels's input signals were rising, then in this case only one channel of the amplifier would be rising, the other would be falling. Did anyone actually try that, and was there any improvement or degradation?
There was also some discussion about turning the loudspeakers to face the wall - the idea being that the sound would be more spread out or something.
I also remember reading about the idea of replacing the speaker leads with copper water piping - e.g. half-inch pipe - with multistrand wires inside. This was suggested because the contemporary idea was that low-frequency signals ran through the body of a wire, and high-frequency signals ran on the surface of wires, so multistrand (with thin strands) would carry the HF and the water pipe would carry the LF. Interesting idea - except AIUI the surface-travelling frequencies are much higher than we encounter in audio.
Another suggestion was that pre-amp, power amp whould be supported on solid, heavy, tables, but the turntable should be on a flimsy shelf.
Any other weird and wonderful ideas?
Having said that if you can cope with the rigidity of copper tubular pipes it will provide a cheaper, high quality, lighter conductor for high power speakers as opposed to using cable...
Beachcomber posted:Would the 8mm microbore copper pipe be a reasonable compromise?
Did you mean 8mm as the outer? That might produce rather a high capacitance cable, depending on the insulation of the inner. Or did you mean as an inner conductor, which with a large enough outer, say 42mm, which might allow air spacing and a lot lower capacitance, though might pose minor domestic challenges... 