cable upgrades , real or rip off

IMO, popular opinion has it backwards, if your equipment is well designed and in good condition, the engineers will have built in significant power conditioning betwixt your incoming ac line & the dc buss immediatly downstream, power cord & other minute effects to incoming voltage will be minimal. If you have old equipment with worn out capacitors ,or the designer skimped on conditioning, you may hear more of a difference. If you are on good terms with a local repair shop, it is very easy to hook up an osciloscope to the dc buss in your equipment and detect any differences. There is no magic to this one, if you can't see a change in dc voltage level on a scope, your equipment can't see it either.

I agree, it is difficult to understand a manufacturer skimping on the power cord of a $3000.00 amp. Power cords and other tweaks are still relatively new to high end audio and their impact can't always be predicted or even understood, using the rigors of applied science. Engineers, like all scientists, like to build components using sound scientific principles. Throughout history, the greatest resistence to anything new, especially if it can't be proved, comes from the scientific community. No disrespect, but IMHO the thread by Jeff_jones demonstrates that thinking.
Due to the prodding of people I trusted, and over a period of time, I tried a number of cords in different configurations with little improvement, then one day everything clicked, the improvement was unmistakable, I was hearing subtleties and even instruments I had never heard before on my cds.

again thanks for the feedback, i can tell from the wide range of responces that this is not an open or closed debate. i did however find bigtee's blind test very intresting.

I think Elizabeth is correct, that is until one reaches the point where changing equipment represents more of a horizontal movement than a vertical improvement.

At that point, a system, regardless of its specific make up (of components, speakers, cartridges, etc) is definitely capable of revealing the very real differences in cabling. And so I believe that is the time to begin this exploration, and probably not before. I also believe that at this point in system development, no further changes should be made in equipment until the cabling is brought up to a similar level as (the already high quality level of) the equipment.