A (the?) modern "solution" is indeed switching (at a substantially higher frequency than the line power) rather than running devices in their linear region. The buzzword is Power Factor Correction, and it also solves the problem of the capacitors being charged only in the peaks of the waveform as well as the high current on startup. This would have to be added as a modification of the secondary circuit of the power supply.
A way to do it without modifying the amp is to generate a line voltage that ramps linearly from 0V to the line voltage over a period of about a second. I vaguely recall some high-dollar "pure sine wave output" line conditioners that could (and should!) do this ramping up as a side effect, but I don't know if they do. That's likely a "value-added" add-on that they would charge more for.
A way to do it without modifying the amp is to generate a line voltage that ramps linearly from 0V to the line voltage over a period of about a second. I vaguely recall some high-dollar "pure sine wave output" line conditioners that could (and should!) do this ramping up as a side effect, but I don't know if they do. That's likely a "value-added" add-on that they would charge more for.
Thank you benb. Actually I though of a switching circuit (sort of like an SMPS?) but it soon became unnecessarily complex. I'm also not sure if the power transformer will be happy with the high frequency switching. They are made for 50/60Hz.
Seems the best solution is still shorting a series power resistor after some time, although can be used with a solid state switch working in linear mode to get a soft, ramp up like starting behavior.
Seems the best solution is still shorting a series power resistor after some time, although can be used with a solid state switch working in linear mode to get a soft, ramp up like starting behavior.