• 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.

Hammond 260E

I have some Hammond 260 E transformers, made in 2006 and 2007. Mine are marked 450v CT/100 mA. Looking at new ones, on Hammond's website, they are marked 450v/115mA. Are they the not the same transformers, or has Hammond just found that they can load them more than before?
 
Want to get more current out of them and with a lower thermal rise?
Then use a choke input filter (need at least critical inductance), and be ready for the 450V x 0.9V DC = 405V - choke DCR x Load current . . . from the choke output lead (no significant voltage drop from the rectifiers if you use solid state diodes, tube rectifiers drop more voltage).

Current ratings are not fixed; they depend on the exact usage of the secondary winding(s).
Go find the Hammond cheat sheet (in some threads) for different circuits; center tapped full wave, bridge full wave, resistor load, etc.
The current ratings are different for different circuit topologies.

If you are needing 115mA and are using a cap input filter (or even need 100mA), you are not allowing any margin in your design.
 
Manufacturers routinely make changes (improvements) to their products over time and it's not unusual to see differences in specs for two parts that were manufactured years apart like this. The safest approach is to respect the specs marked on the transformer that you have. If it says 100 mA, it would be best not to exceed that just because a current production transformer has a higher rating.
 
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