[Patrick Turner]

CyberSlacker wrote:

i have a Jadis intergrated and it has EL 34s they are
getting older so im thinking of switching to KT 88s.

i like em in the other amps i have owned and own,
anybody tried em in a Jadis ????

Should be OK.

BUT, and there is always a but, make sure the PT won't fry
when connected to KT88, because KT88 draw slightly more filiment
current, 1.8A instead of EL34 1.6A.
On the other hand, KT90 have less Ih than KT88, so are OK in this
regard.

Biasing will be different for the idle anode current with KT88.

So make sure that idle current for KT88, KT90, or whatever, is the same
as it was for EL34 which may mean replacing the Rk cathode bias
resistors or
re-setting the adjustable "fixed" bias.
Stabilty with NFB should remain unaffected, and should be unconditional,
but should be checked by a knowledgeable tech if you don't have a clue
about such things!


Patrick Turner.