[Patrick Turner]

On Jan 26, 5:51*pm, King Kong wrote:
Who has built a EL156 SE? I guess it needs feedback due to the nature
of pentode, right?

Please advice. Just bought few Chinese made Valve Art EL156 (octal
base).

If you search the rec.audio.tubes archives then probably you will find
ppl who used EL156 during the last 10 years.
In pure pentode mode, you will need a total of 20dB of NFB, and the
sound will be "pure pentode with NFB" and that won't be as good as
using say 2 tubes in parallel SE in triode for about the same PO, but
with much less NFB. I don't know why anyone would buy such tubes
without understanding what they have to do to make an amp work. To
understand, you have to work from the tube data curves, if you can
find a set , then establish Ea, Ek and the Q point for Ia, and EG2,
and then work out a load so you know just what OPT you will need.

Patrick Turner.