Tube DIY Asylum

RE: Too low plate R value for a triode ? and CCS substitution?

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This Post Has Been Edited by the Author

In Reply to: RE: Too low plate R value for a triode ? and CCS substitution? posted by dave slagle on March 23, 2017 at 10:28:53

What I was trying to say, and doing a poor job, is this.....
If you keep the plate load resistor high enough as to not substantially increase the HD, the amount of gain reduction for a proper value plate resistor to a less than optimum value plate resistor is so small as to be of no real consequence.
Of course the gain will drop if you load the tube with a vertical load line but why would anyone do that?
I guess I should ask Victor.
"I have just bought a BAT VK5se preamp for good deal.
What I have found is the plate resistor being abnormally low value for the parallel 2 section of 6h30. The plate R of 6h30 per section shown in EH datasheet is 840 ohm per section then parallel 2 section is 420 ohm.
However the plate resistor is only 1250 ohm which is less than 3 times of 420 parallel section of 6h30. Is it normal for high priced preamp design?"
So Victor wasn't just "saying" that you can lower the gain of a tube by loading into a vertical load line, Victor is actually "doing" just that.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"

Edits: 03/23/17 03/24/17

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