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At 04:06 PM 2/3/2005 -0500, Steven C. Barr wrote: >...but don't the audio taper and loudness controls attempt to >compensate >for the way the ear/mind works by varying the signal in non-linear ways... >either by varying only the signal level to approximate what is heard as >the control is adjusted, or varying the actual frequency response to >approximate >the response of the ear? If you used only a straight potentiometer...no >taper... >would you wind up with most of the volume variation at the lower end of the >control? Steven, The loudness control is altering the frequency response of the system (i.e., output is not just a scaled version of input) while the audio tape pot is just a human interface convenience so that rotation approximately corresponds to the level difference you're hearing. You can use a linear pot, it's just fussier to adjust. With linear or audio taper pots, the frequency response of the output is exactly the same as the input in a properly designed circuit. Either pot in an improperly designed circuit can show some high-frequency rolloff, but that is poor design, not intent. With the loudness control, the bass and treble are boosted more and more as you turn the level down...or that's how it should be to match the Fletcher-Munson curves I sent the link to yesterday. So, turn the level down and you're turning down the midrange more than the highs and the lows. So, no, I still don't see the similarity. You could use a gear train and cam arrangement or a 10-turn pot to change the human interface on the linear pot. The audio taper pot is just a simple, cost-effective implementation for hand-to-control interface. Nothing to do with the electrical signal except scaling it up or down. Cheers, Richard Richard L. Hess email: [log in to unmask] Vignettes Media web: http://www.richardhess.com/tape/ Aurora, Ontario, Canada (905) 713 6733 1-877-TAPE-FIX