pentode amplifiers

Is there any quick "in a nutshell" explanation why there aren't more pentode
amp designs? I'm guessing it has to do with extreme non-linearity. I am
building a 10W EL84-based ultralinear amp. The triode conversion is a snap
but it drops me down to 5W which is not enough oomph for my 88dB speakers.
Pentode mode would give me 15W which I am inclined to try if it's not too
difficult.

Can anybody point me to a resource where I could figure out the proper
screen voltage required for pentode mode EL84's with an 8K output tranny and
a B+ of 300V? does this voltage have to be regulated, or could I just drop
the B+ with a resistor?

Thx

Dave


.

Relevant Pages

  • Re: pentode amplifiers
    ... aren't more pentode amp designs? ... going to go the route of increasing gain and feedback you ... screen supply detailed in Duncan's guitar amp designs. ... You should check that the pentode amp is reliably stable. ...
    (rec.audio.tubes)
  • Re: Hello SE for RS383 wanted
    ... I'd say that, being the 383 a radio tube, its linearity is probably a bit ... at least in pentode mode. ... > So the use of about 50% UL screen taps would reduce the thd considerably, ...
    (rec.audio.tubes)
  • Re: pentode amplifiers
    ... Is there any quick "in a nutshell" explanation why there aren't more ... Pentode mode would give me 15W which I am inclined to try if ... screen voltage required for pentode mode EL84's with an 8K output tranny ...
    (rec.audio.tubes)
  • Re: Another DIY project finished
    ... how did you wire the 6V6 as a pentode? ... > beam tetrode. ... So can't a 6V6 be in pentode mode? ...
    (rec.audio.tubes)