With my circa-200w VTL monos, the inexpensive aftermarket cord I preferred best among the several I tried was the original Shunyata Sidewinder. Probably like anything in this low price range, it's a cord with discernable flaws (brightness if used in the wrong context, and not the most refined) and isn't necessarily gonna work with every component. But on the tube amps in particular it really lent a welcome boost in the areas of clarity, speed, spatial presentation, and bass control, and just plain made the music come to life better than other similar cords I tried in this application. I also had the opportunity of comparing the Sidewinders at home with its nearest replacement in the Shunyata lineup, the Diamondback, and concluded the latter wasn't as impressive a cord, being more colored and less accomplished in those areas I noted. Sidewinders are 10ga., and were selling around the $125-150 range for 5ft. last I knew but could be lower now.