Hi,
I have one Akai 707 tube preamp and I would like to mod it into a two mic preamps.
I found this schematic that I would like to build:
The only thing that is missing here is a phantom power.
So I was thinking to add this phantom circuit, connecting it to the 230V coming out from the rectifire tube and regulate the 48V with this LR8 regulator as shown here:
Since the original phantom circuit working on a 50V and regulated by a LM317 I guess I need to change the value of some of the following components:
C04, C05, C06, D04, R22, R23, R24
How can I calculate values for the components on the phantom circuit?
I have one Akai 707 tube preamp and I would like to mod it into a two mic preamps.
I found this schematic that I would like to build:
The only thing that is missing here is a phantom power.
So I was thinking to add this phantom circuit, connecting it to the 230V coming out from the rectifire tube and regulate the 48V with this LR8 regulator as shown here:
Since the original phantom circuit working on a 50V and regulated by a LM317 I guess I need to change the value of some of the following components:
C04, C05, C06, D04, R22, R23, R24
How can I calculate values for the components on the phantom circuit?