srinivassa
New member
I know this is unfair to leverage amp builders for my personal information, but I decided to be selfish and ask anyway. You may reprove me at will.
I have been toying with an amp of mine (not an Egnater), and I started to wonder. If I want more gain, why can't I just decrease the the value of the 100k resistor that sits atop the anode. It would cause the tube to pull more current and increase the gain of my first triode stage.
It's hard to see why that would hurt. Since it's the 1st stage, it would only be driven by a small current, and would likely produce a not unreasonable anode current, which would improve my overall gain. Also, some tube datasheets (JJ) do cite different combinations of acceptable anode and cathode resistors which produce more or less current.
However, I know it is a bad idea because it is simply not done. 100k has been at the anode of every triode tube I have ever seen in the preamp. With the noteable exception of the phase inverter, which frequently sports an 82k (dating all the way back to the 1959 Plexi).
Is this the kind of thing every amp builder tries and then finds out why it's a bad idea? I think I may be rapidly putting myself into that category.
I have been toying with an amp of mine (not an Egnater), and I started to wonder. If I want more gain, why can't I just decrease the the value of the 100k resistor that sits atop the anode. It would cause the tube to pull more current and increase the gain of my first triode stage.
It's hard to see why that would hurt. Since it's the 1st stage, it would only be driven by a small current, and would likely produce a not unreasonable anode current, which would improve my overall gain. Also, some tube datasheets (JJ) do cite different combinations of acceptable anode and cathode resistors which produce more or less current.
However, I know it is a bad idea because it is simply not done. 100k has been at the anode of every triode tube I have ever seen in the preamp. With the noteable exception of the phase inverter, which frequently sports an 82k (dating all the way back to the 1959 Plexi).
Is this the kind of thing every amp builder tries and then finds out why it's a bad idea? I think I may be rapidly putting myself into that category.