How do you reliably ABX equipment that needs to be disconnected, and how can TOS #8 be satisfied in such situations? Options

[Arnold B. Kruege...]

Thats probably fine from a blindness perspective, however unless the differences are quite large I think the long time it'll take to switch samples will make it impossible for you to detect a difference. So your test will be blind, but also probably give you a negative result

A valid concern. Switch-over times significantly in excess of 1 second cut listener sensitivity to actual differences in tests we've done to find out the effects of switchover delays.

If one cannot remember the audible impression from sound gadget #1 over a time-span of 5 minutes well enough to reliably compare it to sound gadget #2, what does that say about the benefit I would get in my home stereo if I bought one instead of the other? After all, if I purchase a new amplifier, I do not expect to rapidly switch back and forth between it and the older one for the products lifetime.

This is a critical point. Very few people are able to achieve switchover times that are signfiicantly less than 5 seconds. But, a 5 second or longer switch over delay pretty well destroys listener sensitivity to small differences.

We built hardware switching equipment that reduced switchover dealys to less than a quarter of a second and this boosted our sensitivity to small differences that were actually audible. The technique is described in Clark's JAES paper, and I can asnwer questions about it because I developed it over a period of several years.

The bottom line is that most golden ear A/B tests are inherently *not sensitive* to small differences, should they actually exist, because of their lengthy switchover times.