[sdiy] Tube amp problem

[eric b]

>But this is just for triodes, right? My old Telefunken databook 
>tells me that Rout shall be 2k for a single EL34 in class A SE, 
>while saying that the plate resistance is 15k. 
>(Ua, Ug2 = 265V, Ia =100mA, Ug1 =-13.5V)

Sorry, yes, you're right. Pentodes, IF OPERATED WITH A
FIXED SCREEN VOLTAGE, should be operated with a load
about 1/3 to 1/4 the plate resistance for AUDIO use only. 

If operated in triode or ultralinear, load should be ~ 2-3 times Rp.





E. Barbour
metasonix