6ak5 triode mode disipation

[Kmet]

Hi there...
I need some help regarding power disipation of 6AK5 tube in triode connection mode of operation. I am now saw tube datasheet and for anode disipation is stated disipation of 1.8W and for second grid is only 0.55W. Please tell me what will be true disipation margin for triode mode, 0.55 or 1.65W or something in between?

Thanx in advance

[SY]

Probably something slightly higher than 1.65W. But you have to check what the screen itself will dissipate at your desired operating point, and it may well be that you'll have to back off on the plate just to keep the screen from glowing.

[Kmet]

So, I must check current on second grid during triode mode test sequence? And disipation of the grid must be below specified in datasheet?

[SY]

You can usually estimate it from the datasheet. For a 6AK5, the screen draws about 1/3 the current of the plate, so you're probably safe if the plate is kept below 1.5W.

[Kmet]

Ok, I will try my circuit on test bench during day or two. I have tungsol's and russian (6j1p-ev's) on shelf....
This assumption regarding estimation..it is like law for all pentodes or just this one?

Until this 'project' I always use triodes so this kind of semi triode sound and circuity is new to me..what is your opinion regarding sound of triode straped pentodes?
Thanx for all...

[SY]

Pentodes vary from tube type to tube type, generally between 2:1 and 5:1. You can estimate this ratio by looking at the datasheet.

I use triode-strapped pentodes in my phono stage, so clearly I think they can be pretty good.