fuses - the $39 ones or the 85 cent ones

I hope this fuse of which you speak is not a line fuse. If it indeed a line fuse there is no reason to pay more than a couple of bucks max. The idea that a line fuse made out of gold will somehow improve the sound is ridiculous. What exactly do you think is the cause of this supposed improvement? If you cannot identify the cause of the improvement and somehow prove it (hopefully by application of mathematics like the rest of engineering principles are proven) then you are merely opening yourself up to countless scams. If the goldenn line fuse is going to improve the sound, then why would it not be equally important to keep the operating environment at very precise temperature and humidity levels - or install ferrite beads around all speaker cables and power conductors, or replace all soldered connections on your pcb's with silver solder, or better yet, build a faraday cage around your listening room. My point is that without having an explanation for these useless tweaks the only limitation is one's imagination, or more precisely, the imagination of the person proffiting by the sale. One reason that science is usefull is that it aids in making judicious choices. The proof of science is in the so called pudding. Space travel, digital computers, MRI's, cell phones, etc etc all are possible not through subective what ifs but through predictable outcomes arrived at via a scientific approach. It is not the case that we generally observe a phenomenon and then later explain it with mathematics but rather that the mathematics explain what is possible before the technology catches up.

By the way, if I am mistaken as to the location of the fuse of which you speak, and it is indeed neither a line fuse nor, for that matter, a fuse for one of the rails, then it makes perfect sense that the gold endcaps would make a difference. I was just not aware that any amplifiers used fuses to protect a differential input stage. I would highly suggest that you replace both of the fuses at the same time and purchase only a matched pair.

Magfan - I know I am a bit too shy in my approach and often do not make my point; alas, it's a fault, but what's a mother to do? Thanks for the reminder of repeatability - I knew there was a reason that most of the work I did for medical researchers had to do with replicating experiments - I wonder if the fuse guys replicate their subjective double blind studies. What? there are no double blind studies of what someone's highly reliable ear tells them? Surely you jest! My Faraday cage works great - Norah Jones (or is it Grace Jones) sounds sparkling, there is just a cleaner expressiveness with fuller tones and more depth. I hope yours works out as well. Sure its expensive and a lot of work, but its worth it.

If one is going to replace their power cord and buy gold fuses, it seems that this is all for naught without replacing the romex from the outlet to the panel. You have 1.5 inches of fuse and 50 feet of romex. As to the ripple theory, if we are talking about a line fuse where does the ripple come into play - you don't have ripple on the line voltage, or, another way to put it is, all the ac waveform is is ripple. If the fuse is past the bridge how is that contributing to additional ripple. If the fuse is somewhere down the path on the rails a higher resistance caused by the inexpensive fuses (which I do not think is true) would tend to reduce ripple rather than increase the ripple as the load current would be further limited.

Pubul57: Thought I would respond to your statement which seemed to indicate that you felt that you did not have a lot of knowledge as to double blind tests. The "double" in double blind means that neither the researchers (those administering the test) nor the subjects know which product they are experiencing. In drug studies of course the product is either a placebo or the active substance, but double blind studies are carried out across the spectrum. This procedure prevents both the researcher and the test subject form biasing the test, whether deliberately or unconsciously.

Good pont Timrhu. I don't beleive that there are any insurmountable difficulties in setting up a DBT of cables, amplifiers, power cords or whatever; simply a lack of interest by entities that have the resources to fund accurate and probative DBT's (such as pharmaceutical corporations and government agencies). This is in part likely a combination of no financial benefit to the corps and no significant public interest as to the agencies. Furthermore, as to the more ridiculous claims - no one is going to spend the money because there really is no question to be answered .