I've experienced a number of pleasant surprises over the years. One of the early surprises, after hearing some Klipsch, Altec, JBL and Electro Voice horn systems, was hearing an Edgarhorn system that lacked the coloration that I thought was common to horn systems. After that, I've heard many other good horn systems. Likewise, I did not think that single driver speakers could do reasonable bass and have a reasonably smooth frequency response (i.e., absent a high frequency peak) until I heard Charney's quarter wave backloaded horn systems.
For amps, my early exposure to tube amps were primarily Audio Research amps and I did not particularly like them. I heard a number of other higher powered tube amps that also did not really excite me. It was later that I got introduced to lower-powered pushpull and single ended amps and I still like those kinds of amps. The most surprising single amp I heard was a custom-built output transformerless amp that is one of my all time favorites--very dynamic and exciting sounding without being artificially edgy or harsh sounding.
For amps, my early exposure to tube amps were primarily Audio Research amps and I did not particularly like them. I heard a number of other higher powered tube amps that also did not really excite me. It was later that I got introduced to lower-powered pushpull and single ended amps and I still like those kinds of amps. The most surprising single amp I heard was a custom-built output transformerless amp that is one of my all time favorites--very dynamic and exciting sounding without being artificially edgy or harsh sounding.