[TheOctavist[_2_]]

Tube Rolling:-

Valves have certain specs, which all manufacturers of, say, an ECC83 adhere
to in terms of gain, bias sensitivity, mutual conductance etc. All
manufacturers have production spreads, so that a valve may have low gain,
another of the same type higher gain, but still within the acceptable
spread.

Is there any objectove evidence that a say, Mullard, ECC83 is any different
in spreads and performance than any other manufacturer's.

Is there any objective evidence that a say, Mullard, valve will sound any
different to another manufacturer's valve.

Is there any objective evidence that valve circuits are so sensitive to
changing valves unless it's clear that it's due to the valves being at
opposite ends of their production spreads.

Or is it yet another audiophile myth?


and Hey Mr. Ian, you rock Sir