| ampage Tube Amps / Music Electronics |
For current discussions, please visit Music Electronics Forum. |
ampage archive
Vintage threads from the first ten years
| previous: Doc The 8k p-p load is normally seen in... -- 8/13/1999 4:31 PM |  |
|---|
Re: Choosing an OT: Theory Q's
 8/16/1999 8:09 PM |
||
| Ken | Re: Choosing an OT: Theory Q's Doc said:
I don't mean to be nit-picky, but this isn't perfectly true. Maximum power TRANSFER actually occurs when the load impedance is conjugate to the generator impedance. Assuming pure resistances for simplicity's sake, that means max power transfer occurs when Rl=Rp. Now, whether or not that makes max power OUTPUT depends on the ability of the driver circuit to increase it's voltage swing output. Assuming that this is true, then max power OUTPUT for triodes occurs at Rl=2Rp, as Doc points out. Note that this is NOT due to more efficient transfer of power, but rather because the load line is tilted in the counterclockwise direction, enabling a more negative excursion on the grid before the tube pinches off. Likewise, that means that there is also a higher permissible positive excursion possible to retain symmetry about Vg at idle. There is more power output because we are GENERATING more power, not because the transfer is more efficient. Nit mode off 
KG | |
|---|---|---|