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Phil Allison[_4_] Phil Allison[_4_] is offline
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Default Triode Naming Convention

Xtrchessreal wrote:

=======================
Section 1 is so called due to lower hum compared to section 2.


** The 2 triodes of a 12AX7 / ECC83 are identical,
one doe not "hum" more than the other.

================================================== ===

Internal connection arrangements for grids and heaters vary
between versions and brands, maybe having a small effect
on capacitive coupling if high impedances feed he grids.

It is very common to use DC voltage for the heaters to
eliminate any issues whether grid or cathode related.


Just read the REMARK on the bottom of page one. https://drtube.com/datasheets/ecc83-philips1970.pdf



** My post is *about that exact remark* - explaining it.

An *earthed* internal link from pin 9 travels past grid pin 7 in the scenario described. A link carrying 3.13VAC travels past grid pin 2.

This might inject up to 1mV into pin 2 if the grid source impedance were *10Mohms*. However, for a MM phono cartridge, the impedance is 1kohm at 50/60Hz and for a guitar PU about 10kokms.

So hum injection falls to under 1 microvolt in the above examples and is buried in tube noise - so completely inaudible.

I don't understand the perpetual misinformation.


** There is a great deal more to your not understanding.

But hey, thanks for making my point more clear.


** You never made any clear point - sunshine.

..... Phil