Tube Amp Archive

hi
power transformer secondary is at 578v ac which is ok
but my question was more about the biasing
if i do not harm my tubes with the 370v plate voltage and 47ma current

hi

yes iam using the output transformer shunt method
the heater are at 6.3v
i expected 415v on the anode but think 370v will be ok
the negative voltage on pin 5 v4 and 5 is -27.5v
with the current at 47ma

hello

i have a plate voltage at 370v (pin 3/ground) on v4 and v5
which seems a bit low
I biased to a plate current (pin3/ output transformer center tap) at 47ma
is that correct? with EL34s

nice job,good sound and great playing
I need to buy a microphone do you think SM57 is the best quality/price choice ?

HI Cliff

Yes that is true i have recorded it with a USB karaoke game microphone
directly to the computer sound card

incredible

Hi I just finished my first express and i would like to thank you all for the help you gave me for this project. Special thanks to RJ for providing high quality parts ,thanks to Ron Worley for the precious building guide. The Express is very touch sensitive like having microphones in the fingers lik...