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.
Yes, there is one I use, made by Johan Heikkilä called "DC Filter Choke Designer".
You look it up in the web, it's quite good, although with some bugs regarding the character you use for decimal separation ("," or ".")