• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

multiple independent grid biasing from 1 mosfet

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
In a recent thread parallel output tube advantages and disadvantages were discussed. The thread starter wanted to implement it using mosfet drives (ala powerdrive). Some thought it should be implemented with a mosfet for each driven tube to balance the drive manually. Here is a possible circuit that can balance each tube bias individually and manually while using just 1 mosfet (2 for PP). The rheostats shown could just as easily be potentiometers. Comments welcome.:cool:
 

Attachments

  • multiple grid biasing from one mosfet.jpg
    multiple grid biasing from one mosfet.jpg
    107.8 KB · Views: 96
You might be right. I hadn't thought about it correctly. It looked like it would work but it will require some kind of mod that might be much more complicated than it is worth. Maybe someone else can come up with a modification that can make it work without adding more active devices.
 
Last edited:
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.