what if the max number of 12ax7's you can run before preamp distortion sets in ?

with a humbucker slightly hotter than an original paf

Who do you think you are !? Barney Oldfield !?

That would be one 12AX7. Assume a tone stage in between gain stages like a BF Fender. But this is also dependent on the gain derived from the stages. Lets say 250 volts on the plate through a 100k ohm resistor, a 1.5k cathose resistor bypassed with a 25uF cap and a 1M grid resistor. Typical high-gain set-up. In a Marshall/'59 Bassman circuit it's easier since you have two stages then a cathose follower before the tone section.

If you want more headroom, decrease the gain of the stages.

"Understeer is hitting the wall with the front of your car. Oversteer is hitting it with the rear." --"Fireball" Roberts

just one tube, what goes on internally and how we can increase gain

12ax7

heater : increased voltage will increase output but it is best to leave it stock because there is little margin here

cathode : increasing voltage ?

control grid : reducing voltage

anode : increasing voltage

now we'll add the other two grids for an el34

screen grid : increasing voltage

suppresor grid : little effect on gain , keep very near same voltage as cathode


correct any flaws you see

Basic design parameters. Better yet, pick a circuit you like and copy it. Then you can increase gain by altering the cathode resistor, adding or changing the value of the bypass cap or increasing the plate load resistor. Each change brings with it a change of tone, not just gain. Paper amps have no tone. Start with something, like a 1959 and then experiment.

"Understeer is hitting the wall with the front of your car. Oversteer is hitting it with the rear." --"Fireball" Roberts

http://www.tubebooks.org/tube_data.htm

A whole lotta tube books online. Some of these PDFs are large. But instead of opening them you can right click and save them on your 'puter and just let them download.

"Understeer is hitting the wall with the front of your car. Oversteer is hitting it with the rear." --"Fireball" Roberts

it's a big PDF so it needs a little time to download.

http://www.tubebooks.org/tubedata/beam_power_tubes.pdf

"Understeer is hitting the wall with the front of your car. Oversteer is hitting it with the rear." --"Fireball" Roberts

http://www.freewebs.com/valvewizard/gridstopper.html

http://www.vacuumtubes.net/How_Vacuum_Tubes_Work.htm

Who do you think you are !? Barney Oldfield !?