Threshold S/500 II power cord suggestions?

Wow, from your description of the sound, it almost seems that your amp is unstable and going into ringing. You may just want to look at some simple waveforms on a scope, if you have any friends that have one, to see if it is misbehaving. The Threshold should really be quite invarient regarding load resistance and capacitance.

Unsound: Can't help you with the ringing issue.Never had a hint of problen with the S/300 for about 8 years or so. You may have other issues here.

Its really subtle. Perhaps my choice of words is too strong. Most noticable on female voice where the singer just gets past normal voice to extend into that stronger but oh so feminine fequency and by some of the sharper high notes on piano. In both case there is a touch of this glare, a tiny bit of brightness. One really has to listen to hear it elsewhere. Extreme high freqeuncies like cymbals and triangles are beautifully delicate and shimmering. The bass is extended, powerfull, rich and tight. The midrange is natural with no undue chestiness. Soundstage is wide, high and deep. Performers have space all around. Other than the one issue I've mentioned everything seemlessly integrates. If I can fix this sublte issue, I'll be very happy indeed. By moving some things away from the amps, tightening everything from drivers on baffles and RCA's on interconnects and components, to dressing the power cord, its all but dissappeard. The amp has recently been gone over by Jon Soderberg, so I have good reason to believe its behaving as it should. This amp doesn't like to be shut off either! The amp is a good case for the problems inherent in double blind "shoot outs". It takes time for it to warm up and be its best, even after just a brief rest.

I am using a magic cord power cable from Signal Cable on my Threshold S350e with good results. Inexpensive and maybe worth a try.