On Nov 3, 5:45 pm, Ian Bell <ruffreco
...@yahoo.com> wrote:
> I just tested a EH 12AX7 in the same set up as my last post and it
> measured -68dB 2H and -78db 3H. Stage gain was 87.
> Cheers
> Ian
Hi RATs and Ian,
A person of possibly similar interests published his work and results
some time ago in the Japanese magazine, MJ, I think (or confabulate,
whatever).
Anyway, rather than compare tubes in a fixed circuit, he made changes
in the circuit, re-using the same tube.
Then, he changed the tube, all single 300B tubes, only, and repeated
his search procedures.
At the end of an obviously long and meticulous process, he concluded
300B tubes were pretty decent performers...
He found he was consistently able to achieve outstanding results, but,
the circuit values of that optimal performance changed from one 300B
tube to the next. Same mfgr, same production codes, and also other
mfgrs, codes, etc.
It is obvious we can keep the circuit constant and compare various
tubes in it.
What is not quite so clear is that we learn anything of value, as
listening end users, from that process.
Real engineers must design circuits which will not fail, given known
specifications of all the components.
We may improve an aspect of the performance of those circuits, for a
given individual component.
These are not similar endeavors.
The engineers generally make more money. And, I have known many
engineers who honestly enjoyed their work, year in, year out, so - we
may or may not have more fun ;)
Happy Ears!
Al
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