I am trying to calculate the fist capacitor in the power supply. I am using this formula:
C = (t * I) / V
Where:
I = average load current drawn
V = ripple voltage peak-to-peak
t = duration between charging cycles and is equal to: 1/twice mains frequency. 60Hz, so: t = 1/120 = 0.008 seconds.
I am going to use 4 12Ax7: 2 for preamp, 1 for PI and 1 for reverb. The current draw would be 40mA.
Power amp: class AB2, 6L6GC Push/Pull. From data sheet looks like 210mA.
I= 220mA + 40mA =260mA
Ripple should be 10% of transformer voltage. Transformer is 325-0-325.....325X1.4=455volts.......10% of that is 45.5volts
Back to the formula
C=(.008x.260)/45.5
C=(.00208)/45.5
C=45.7uF
All the schematics show a 100uF or 200uF cap to be the very first cap. Isn't this too big? Will this cause unwanted "ghost notes" to be produced?
Did I do this correctly?