I was looking at the oxytocin Wikipedia page yesterday, and came across this surprising thing:
There are indicators that oxytocin may help to decrease noise in the brain’s auditory system… It may also enhance reward responses.
Oxytocin is a naturally occurring hormone, and the above suggests that if you want better, and potentially more rewarding, SQ, it may be helpful to stimulate oxytocin production before a listening session. Consult the Wikipedia page for ideas about how one might do that.
And, evidently, have more sex.
I’ll sprinkle some over some copper wire and put a substantial mark up on it.
You make it, I will market it and split the MASSIVE profits! 
We all have these nights that the audio system suddenly sounds much better than ‘normal’. I always wonder what mechanism is behind this phenomenon… there could be thousands of explanations, from technical to psychological, but maybe this is one factor.
Have you seen the price of blue pills?
On second thoughts, you could buy a couple of years’ worth for less than the cost of a mid-priced DAC! 
Maybe you’re on to something here…
I’ll have a Serotonin and Dopamine thanks.