Sure, it's easy enough to do one of several ways. The most straightforward is to use pre regulation of sorts to keep the headroom in check. That is, if you need to deliver say 80 Volts, set up your raw supply to deliver 100 Volts or so to the pass bank. The raw supply is raised and lowered either in steps (transfomer taps) or with a 'variac' for continuous control. A conventional regulator and pass bank does the work.
You can also just set up a raw of say 140 or 150 VDC and 'take the gas' in the pass bank (which needs to deal with seven hundred watts or so.....).
Switchers are another option, but not really simple.
For the truly adventure prone, I suggest "Mag amps", an outdated idea (WWII) where a series inductor is used to block AC while a second winding (with a lot more turns) is fed DC by the regulator which forces the core into saturation, removing Xl (the inductive reactance), passing current. This is the scheme that B29 gun turrets used, for instance. Gains of thousands are easy, long working ranges as well. Because the 'losses are inductive', efficiency can be fairly high (meaning runs cool).
Doug Owen
