I was at my tech today, he and his brother have been fans of vintage gear for 60 yrs. My tube pre-amp has been there for 3 weeks. I left my amp, CD player to make sure any problems got sorted. I had been getting reports over the phone how all the old boys loved it, over his old beat up Scott speakers. A bad fit w the pins caused a channel to drop out w the pre...they fixed that 2 weeks ago. All this time the tone controls weren't working..they finally found yesterday, that 3 resistors were shorting against the chassis..simple fix, but hard to locate. Anyway, we got into a discussion how speaker tap for 16ohm sounded best, despite 8 ohm speaker. Something as simple as this should be tried by the ear test..to hear what sounds best..no measurement will tell you this. We also agree there are many who cannot hear subtle sonic change. I now have to make a CD for my tech. Seems he agrees w my test CD(Dire Straits-Brother's in arms) He had been playing over and over at the shop..I was there a couple of weeks ago and someone yelled to 'crank it up' It was great ! Called them a bunch of old hippies. Really, what would be the point of measuring something, if you can't hear a sonic improvement? The spec wars of the 70's w transistors, killed tube sales. Thankfully the tube diehards knew the sound they were missing.