My case, point by point.
1. Actual disassembling of the amplifier was so simple that it left no room for error. Cover off and out of the room (I actually did that on purpose).
2. I used the fist around the screwdriver. Otherwise, I am not the best for the finest fine motor work, but this required nothing of that kind.
>>>>Did you disconnect any cables or power cord before removing the cover?
3. The whole point is that even the lousiest system can reveal differences. That is why tweaking is done, I think, and old Sherwood receivers and similar items used. Mine is nothing spectacular, but it works in general. It shows differences when a piece is changed.
>>>>>>I’ll be the judge of that. Your opinion is kinda irrelevant. Works in general is not what we call ready for Prime Time. We are throwing your results out.
4. Everything seemed to be working as expected. No hum, buzz, nothing unusual.
>>>>>>Well, working as YOU expected. See the problem?
5. I doubt that, although it is of course possible. I hear all the frequencies with a small dip in acuity at 14000 or 15000 Hz (I forgot which one it was about two months ago) and have no hair over the ears.
>>>>>Of course hearing as a skill has very little to do with frequency response. Especially a self appointed anti audiophile. This is obviously your first rodeo. It’s not mine. 🤠
6. That one is hard to measure, but I, in fact, wanted to hear the difference. If anything, I was more biased towards confirming than rejecting the hypothesis. Aside of that, there was another pair of ears (much younger and completely unbiased, practically not even being aware of this thread) that also could not hear any difference. I have left that fact out until now to be one to one level comparison.
>>>>>Whatver.
7. The day was beautiful.
Points 8 and 9 are impossible to evaluate for an ordinary person. Tuneland experts and me included. We have to assume that those were equal at the time of testing. Next stop Bora Bora. Everything sounds better when the floor is of volcanic origin. Much better than maple.
>>>>>Keep a log. Solar flare and sunspot activity is undated daily on:
https://www.spaceweatherlive.com/en/solar-activity
Obviously folks would rather sweep this issue under the carpet.
quick summary: pretend all the variables don’t exist. Then demand your negative results count as much as positive results.