parallel sections

[memphissound]

Would someone here please help me with the gain calculations of parallel sections of an amplifer circuit? Something like the input driver of a Fender BF reverb system, or the gain stages in a Matchless guitar amp. Wheather it's mathematical or graphical is fine. The graphical might be a little easier to communitcate. Thanks.

peace,
memphissound <><

[Tubes4e4]

Hi memphissound,

when you parallel two sections of the same type, you get the same mu, half the rp and double the gm of a single section (given you half the value of the plate- and cathode resistor, too).

In real life circuits, stage gain (note: not mu!) might rise a wee (moot) bit because the loading (due to the following circuitry/stage) of each paralleled section is only half to that what a single section alone would "see".

Tom