Is positive reinforcement why things are sounding better?

So I buy a nice amplifier and later I buy a nice preamplifier and then later I buy Nice speaker cables and each time things seem to improve nicely.

And then I buy telefunken 12ax7 nos tubes for a tube amplifier, and improved tonality, clarity and  a tighter sound is what I get and it's very engaging (tubes are only a few days old). The cymbals seem to come through with more openness.

Things seem to be sounding pretty good and I'm saying to myself is it real or is it just positive reinforcement playing with my head? And the devil is telling me oh let's buy more NOS tubes for the rest of the amplifier. The effects of positive reinforcement can be very expensive. 

Just curious if positive reinforcement experiences have occurred for others, and how can you really tell?