A testy bunch indeed, but no pomposity.
@Justamusicfan , from the "nice-guy" nature of your posts, it appears that you are definitely not a troll, but just not used to the rough and tumble world of science and the way claims and conclusions are challenged, especially when such claims defy current scientific knowledge and evidence-based conclusions. Scientists have to have a thick skin to handle such an environment, but such a combative environment helps to assure that scientific findings are valid. I challenged your "observations" because they run counter to scientific knowledge.
You posted a personal opinion based a method of attempting to discern audio differences that has been proven by science to be completely unreliable. Being reasonably well-versed in science and rebutting subjective, unconfirmed claims does not make one "pompous."
Part of my basis for challenging you about op-amps and sound is the fact that
@amirm , the owner of this website who is a digital audio engineering expert and a high-level "trained" listener, rolled op-amps and found that they made no difference in sound quality. Measurements showed very little difference - way below the threshold of audibility - in the audio signal. (See the quote below for his conclusions.)
Like anyone else with a decent knowledge of audio science and psycho-acoustics, I am aware that listening tests that are hours or days apart are completely useless for detecting sonic differences. You stated specifically that you "believe" you heard a difference, but science is not based on beliefs. You may have indeed "heard differences" because that's the way the human brain works. You can actually "hear" differences when the sound waves striking your tympanic membranes are identical. Don't feel bad that your brain fooled you - it happens to all of us. Many of us who have been around audio for decades have had our "beliefs" challenged now and then over the years, and learned to accept that we were occasionally wrong about some things.
I suspect that you came here because you discovered the old posting of the tear-down and analysis of the Emotiva DC-1 DAC, a component that you said that you bought used and have modified. The particular example that
@amirm tore down apparently measured well and sounded fine, but had lousy and dangerous wiring layout, no proper chassis ground, poor hand soldering, and used cheap, inferior capacitors.
Regarding op-amps, although I am not an expert on them, I do read a lot at ASR.
@amirm tested op-amp rolling with both a cheap and an expensive DAC, and inexpensive and expensive op-amps, and came to this conclusion: