All i ever bought was without ever be able to hear it before...
Save an headphone i discarded because i was not able to modify it really with improvement...
I was never unsatisfied with my main purchases...( save the headphones none of them pleased me till the K340 which i optimized also though)
i read and study for months before buying...
I was unsatisfied by my last purchase , top tube headphone amplifier near 2,000 bucks...It was a good product but unable to drive the picky K340...my top Sansui Alpha do it at a level which is impossible to beat, i paid to know it...
I return this famous tube headphone after one hour without too much money lost... ( almost 300 bucks i lost )
The key of my S.Q. level satisfaction was not purchase synergy which is the first important things to adress for sure..
it was as i said studying and experimenting with mechanical,electrical and acoustical devices and installations (homemade) ...
How can you be deceived by 2 top Sansui amplifiers or the AKG K340?
Or low cost top product as Fosi or Douk audio ?
My best dac is the french now unobtainable French Mariac SPS Nos battery dac ...Minimalistic design.. No fault ...
The other is very good too : Hidis AP80 pro...For the K340 it is perfect i even can set the right equalization...
My most deep discovery is how to obtain the best sound with anything using acoustics knowledge (according to his quality level, no cheap speakers will beat a top one even with perfect acoustics tuning, but a low cost system can beat a very costlier one which is not in a controlled room especially for it ,trust me)...