Alexandru marian
Well-known member
- Joined
- Oct 13, 2014
- Messages
- 127
I wonder how important is to have good filtering on the polarization supplies. As important as say the B+ ?
Thanks!
Thanks!
Filtering for polarization rails? (tube mics)
- Thread starter Alexandru marian
- Start date
Help Support GroupDIY Audio Forum:
Matador
Well-known member
It's important.: any AC modulation of the polarization supply will (mostly) appear as a signal right on to the amplification stages. And due to the high impedances, even tiny noise currents can look like significant voltages.
However the high impedances also mean that very small capacitors make very good filters: at 100Meg, to get a 1Hz filter one only needs 5nF of capacitance. At 1Gig, it falls to 500pF.
However the high impedances also mean that very small capacitors make very good filters: at 100Meg, to get a 1Hz filter one only needs 5nF of capacitance. At 1Gig, it falls to 500pF.
