Oh, that's really interesting. Right, I'll pull the chassis out and find some ECC83s tomorrow, and get the kids to help me do a blind test. (It's OK, they're old enough that this is not abusive and/or dangerous
). Any suggestion for doing it clean / bit crunchy / really fuzzy?
(Full disclosure - I'm a terrible inverted snob, and I'll be sad if I can hear a difference - as I was when I could tell a difference and even express a preference between cheap Whisk(e)y and something pricey! But I promise to be true to science
).