/diy/ - Do It Yourself

When some one designs the power supply voltage dropping network in something like pic related, what is the process? Do you use the quiescent currents to calculate resistance and treat the triode sections like resistors? Is there a fast way to do this?

>>1489791
Hey fellas. I built this preamplifier. I works very well and the amplified sound out of it is pretty clean and clear for a high gain amp. The issue is that tube V3 makes a sort of hissing noise. The noise isn't electrical, it doesn't come through the speakers (I only hear it when the speaker output is switched off) it is some sort of mechanical sound. Any one got any idea what's up with that?