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On 20/12/2011, Richard L. Hess wrote: > Hi, Don, > > The time/phase error at the stylus tip could cause significant > problems if an attempt was made to create a mono sum of the signal. > It's the same thing we see with tape azimuth. > Yes, but why would anyone want to create a mono sum of the signals? The old reason was for broadcasting, but nobody is broadcasting from vinyl now. And did this effect cause any problems in practice when they were? > The 1/400,000 of a second at 78 rpm would translate to approximately > 32 degrees of electrical phase angle difference at 15 kHz at 33.3 rpm, > which is not huge, but significant. This is the order-of-magnitude of > azimuth wander seen on less-than-ideal, but not horrid 3.75 and 7.5 > in/s tapes. > > But you are certainly correct that a one foot path length difference > would produce an error of a full cycle at about 1120 Hz, but somehow > we don't hear that path length difference in the same way we hear a > mono sum before the signal is fed to the speakers. > Regards -- Don Cox [log in to unmask]