Op Amp Advice – RQ970BX Phono Preamp Andy Grove Mod

Familiarity plays a big part in determining differences. If a configuration and content is well known, it is much easier to find difference. Blind testing with unknown equipment and content is useless. Learning to section the frequency response as you listen is down to training. However, once this is learned, it is difficult to return to normal listening.
 
Thanks for the comments gents. At least my mind has been straightened out as to what I will do. Firstly I will spend the next few months listening “critically “ to a selection of music. I will do the mods in three steps :
1. Change output caps and insert opamp sockets with the original opamps in original positions in the socket. Then listen to the selection of music to hear if there are any changes / improvements.
2. Replace components in front end - listen………..
3. Play around with some opamps………
Hopefully I can discern the changes after each step and hope to report on same on the forum.
 
Hopefully I can discern the changes after each step and hope to report on same on the forum.


It really isn't worth it unless you do double blind tests, like random ABX or similar - the brain cheats when it can (expectation bias), and auditory memory fades after 7 seconds or so. The differences between opamps are very small, like 0.005% THD v. 0.0005% THD. Noise floor is pretty much the only thing that might be obvious if you are comparing preamp circuits for instance.


And even if you do blind testing you have to be ultra careful to level match, a fraction of a dB louder and the brain likes it more (louder always scores higher it turns out!).