In this application the actual resistance is non-critical, The major requirement is that the resistance is large enough to avoid current issues (power dissipation etc), 50K meets that fine.

OK, now I am confused. (As if that were difficult to accomplish!)

As I understand it, the resistance is going to vary from 0 ohms to 50,000 ohms, depending on how far around I crank the knob on the potentiometer.

At no attenuation (zero resistance) the power from the signal line just passes straight through, no heat dissipation problems, no reduction in sound from the amplifier.

What happens at maximum attenuation (50,000 ohms)? Isn't that where the maximum power has to be dissipated? Will the potentiometer then have to dissipate more than the listed 1/4 watt? Will the signal reaching the amplifier be effectively reduced to nothing?

If I visualize this correctly, other values of potentiometers (like 10K, or 30K, or 100K etc.) differ only in the maximum amount of reduction of signal strength to the amplifier. For the sake of the argument, lets hypothesize that a 30K resistance would achieve my desired "effectively nothing" signal to the amp. In that case, the remaining 40% of the 50K potentiometer would be wasted, overkill, and my useful range of adjustment on the potentiometer would only be the first 180 degrees (out of the total 300 degrees) of rotation. Or, to take the argument to extremes, if I used the 1000K potentiometer, after the first nine degrees of rotation (starting at the zero attenuation point) the amplifier would be receiving no signal, making accurate adjustment difficult.

This is why I keep coming back to that 50K figure. Yes, 50K will (probably?) bring the signal strength down to zero. But if 25K would do the same thing, then I would get twice the "resolution" when it came to making the fine adjustments.

So, what is the optimal resistance, assuming I want at least a 40dB reduction in output while minimizing granularity on the tuning? Is this calculable, or should I just order a whole bunch of pots of different values and do it by trial and error?

Finally, that 1/4 watt maximum power dissipation still bothers me. 1/4 watt really isn't very much. A bulb in a penlight uses more power than that. Is a line-level audio signal really so puny? I don't work with this stuff, so I really have no feel for it at all...

tanstaafl.