Would you change your amp selection knowing...?

ieales -
Thanks for the bi-wire capacitance info.

Don’t want to sidetrack this thread into a defense of Paul Laudati and Clear Day Cable though I will say I’m inclined to take him at his word. Paul has been around a while and it would be a fairly easy task to "autopsy" one of his cables and refute his solid silver claim if it were bogus. To my knowledge, that has not happened. I can report the Double Shotguns were better with my gear than Morrow Audio SP-4 silver plated copper...and not by a little bit. They are also preferred in one amp/speaker combination I have over Cardas Parsec cable. The review at the link below, while largely anecdotal, might be of interest.

http://www.highfidelityreview.com/clear-day-audio-cables.html

@unsound
I found a link to the paper from which the excerpt shown at the link you provided was taken:

http://sound.whsites.net/cable-z.htm

My conclusion reading all of this is that I wouldn’t worry about his allegation that the resistor value chosen by Goertz is not ideal. As he even said, based on his simulations: (Comments shown in brackets are mine):

Even 100nF in series with 10 ohms restores the amplifier phase margin to normal.... 4.7 ohms is preferable, but the phase margin is barely affected. The speaker end response has a small ’lump’ with 10 ohms [between about 5 and 10 MHz!], and phase goes ’wobbly’ at above 20MHz. This is probably not a concern, and you will almost certainly get away with it.

I don’t, however, see any reason to doubt his statement that:

It is very evident that this particular cable [Goertz MI 1] should never be used without a Zobel at the speaker end....

Best regards,
-- Al

Would speaker cables that use separate jackets for the + and - speaker have zero (no) capacitance?

Unsound, thank you kindly for the gracious response.  Cycles2, separating the two conductors as you describe will result in capacitance being very low, although not zero.  However, it will cause inductance to be considerably higher than if the conductors were in close proximity.  And in a speaker cable inductance is much more likely to be a significant factor than capacitance, aside from the situation that has been discussed in which cable capacitance is ultra-high and the amplifier is sensitive to that.

High inductance is particularly likely to have significant sonic consequences if speaker impedance at high frequencies is low (such as in the case of most electrostatic speakers) and cable length is long.  That is because the impedance presented by an inductance is directly proportional to frequency, and cable inductance is directly proportional to length.

Regards,
-- Al