As the original poster I do think it is important to remember I few points that I wrote about the topic.
This was an experiment to see if there were sonic differences using three different fuses - each installed and removed multiple times and in both directions. A well know respected amplifier brand ( Pass Labs) was used that has a reputation for having a excellent power supply. This was done on purpose to discount the experiment being devalued due to a "poor power supply being a factor in the observed results".
No other changes were made to the system for the past five months. So there are no other known major variables going on. The humidity (measured), and room temperature (measured) were kept constant. The time of day for listening was kept constant - 8:00 to 10;00 at night. The Pass Labs amplifier was also chosen as it can and was left on 24/7 (except when it was turned off to change fuses). Since this amplifier has a screw in fuse holder, fuses can be easily and safely changed.
This was a serious attempt on my part to do a meaningful evaluation of three fuses and their sonic effect on a well respected amplifier. It is the first of several experiments I have planned pertaining to this subject.
It was earlier pointed out earlier that testing - evaluating fuses is " by necessity a time consuming affair". That is absolutely correct and one reason I chose to report this experiment. It is a lot of work. It takes a lot of time.
My observations indicating a change in sound have not and will not ever have a percentage number assigned to them.
I have found it very helpful to watch all the You Tube videos posted featuring interviews with Nelson Pass and his co-designer Wayne Colburn of Pass Labs Inc. I will not attempt to condense what their approach to perfecting a design is but it involves both measurements and a lot of listening. Nelson also discusses the subjective and objective and their place in developing audio products.
Wayne Colburn of Pass Labs has been most gracious in his time and expertise to directly answer questions I had about Pass Labs's use of fuses and circuit breakers.
David Pritchard