Tubes Tubes

[Hallgeir Helland]

Don Tillman wrote:
>    The tube transfer curve is somewhat linear in that the harmonic
>    distortion is almost entirely first and second harmonics.
> 
> Arrggh!  Of course I meant second and third harmonics.  Both from the
> transconductance curve of the tube and from the dynamic variation in
> plate voltage.

I've been told that there's a significant harmonic difference between 
triodes and pentodes in the output stage of a tube power amp:
triodes have far less harmonics from the fourth order and upwards, than
pentodes do. (this is when the output stage is slightly overdriven)

So triodes are favourites in the output stage. Preferably single ended,
class A and zero feedback. :-) 

Tell me if I got it wrong.....

thanks,
Hallgeir

-- 
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 Hallgeir Helland   hhelland at mailandnews.com     
    Evlogia           http://fly.to/evlogia
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