Tube DI Box

[ruffrecords]

Thanks Merlin. It should be somewhat better with something like a VTB2291 wired 2:1 step down.

Cheers

ian

 

[ruffrecords]

OK, here is a draft schematic for the tube DI box PCB. The idea is that it is flexible enough that you can build almost any version with it:



The lower triode can be configured as either an SRPP, mu follower, White follower or single ended input stage. The top triode can be configured to complement the bottom triode configuration and in the case of the single ended input stage, the top triode can be configured as a cathodyne or a simple cathode follower output stage.

There are four connectors: HT, heaters, input and transformer. If we keep the HT on the top triode down to 250V there should be no need for heater elevation.

Cheers

Ian