tunetown wrote:As a further aside, can someone with more intelligence than me explain why valves sound different. If they are of the same value and biased correctly I assume they should sound the same. I understand the noise and microphonic issues but isn't a circuit a circuit?
I'll endeavour to answer this in an easy way....(as it's 2:34am and I've done 5 gigs in a row)
It comes down to manufacturing process and components, tolerances and low noise..
Mil spec tubes were manufactured for the Military and were produced to a high standard.....
I've got an 1961 scarla amp made in Italy, point to point 3 tubes etc, I was using it as a testing amp for 12AX7's for a friend who had bought around 200k tubes in the 90's, we were grading them on sound quality and noise etc....
we Tried milspec Jan phillips, 60's Brimars and Mullards, RCA etc etc, they all had their sound, the Jan phillips were clean and would last a lifetime, the Brimars had a golden type sound, Mullards were mullards, for fun we threw in some modern russian and chinese ones and you could hear the difference straight away....
At the end my friend (who was grading them to sell OS) had a couple of used Telefunken black diamond 12AX7s which he put in just to see what they were like..... I am not joking when my Jaw hit the ground when I heard them and offered to buy them on the spot, he refused but a few years ago he sold them to me...
the Telefunken black diamond are considered the best 12AX7 ever made and having heard them and now owning them I can see why...
Why is this so, I guess it's where science meets art