choke question

[12AX7]

So as opposed to a resistor a choke usually allows higher voltage and i know how that affects things. But exactly what does the choke inductance value do tone wise? For example, with all else being equal what would you hear thats different between say and 4 and 20 henries ? I read the aiken article but that wasn't clear to me.

[PRR]

Better buzz filtering.

[shooter]

^^^what PRR said
inductors don't like changes in current, so they oppose that change.
some like their PS to sag as part of their "sound", the bigger the Henry, the less likely that sag will happen

[12AX7]

so would i likely get much sag with a 4 opposed to a 20H choke? I might actually like that. (I've tried sag resistors....doesn't feel the same)

[pdf64]

I think sag may be more related to the choke’s resistance. Higher inductance requires more wire, so resistance goes up, unless a bigger core is used to allow thicker wire.

[12AX7]

Makes sense. But probably not very noticable since if you use a resistor it takes about 5-10 times the resistance as a typical choke R to get say.

[pdf64]

But then a typical 20H choke will be maybe 5 x the resistance of a 3-4H choke.
I either use vintage AC30 / RS spec chokes, about 20H and 500ohms resistance, or add series resistance to regular chokes, so as to get plenty of resistance between OT CT and screen grid HT nodes.
That helps to mitigate excessive screen grid dissipation when the amp is cranked.

[12AX7]

Yeah, but is that even necassary if you have large enough screen resistors? I already have 1k on each screen.

[pdf64]

I’m not keen on high value screen grid resistors, there’s an audio effect, probably caused by the local negative feedback, that I don’t care for.
How are you assessing that 1k is right?