SMPS for the Masses.......

[leonski]

Well, It seems that EMO was if not 'ahead', than certain in the first BIG wave.
Many manufacturers are now going in the switcher direction.   Weight savings is certainly an issue......Toroids are heavy and
if not packed correctly, can damage gear.     Design has caught up with desire and the new generation SEEM to be very reliable 
while having good characteristics, otherwise....
I'm not going to make a list, but just look around......

This is NOT all 'D' amps, either....

ME?   I'm waiting for a TUBE AMP with a switcher.  That'll eliminate ONE of the 3 transformers on a stereo amp.....cut weight, maybe
improve efficiency and reduce heat output.    Are there such power supplies which will run tubes around 500volts?   I don't see why not......
A SMPS at heater voltages would be EASY.    I have a small PS from MeanWell which is 12v at 3 amps......= 36 watts.     It is TINY and very 
well regulated.   I've run it up with a good load and the output stays stable....
Is there an advantage to tube amp heaters running DC not AC?     I'll leave that to the tube guys.....

[leonski]

I just did a little looking around.

Experimenters and DIY types are thinking about this.

Some circuits are being tested and some are maybe already discarded. Getting high voltage out while not inducing all sorts of noise IS an issue....

Some posts mention a 'flyback' which I remember from CRT TV Days......as a way of getting a high voltage OUT.....

but this is all over my pay grade, the main thing being that others have already started down this path....

Commercial power supplies ARE available up to maybe 500v.....but at not more than 100 watts....SO FAR.

[405x5]

“c. 1936
Car radios used electromechanical vibrators to transform the 6 V battery supply to a suitable B+ voltage for the vacuum tubes.”

A most primitive form of going down the “SMPS” path. I dunno 🤷 about “for the masses”. Or hardly for reincorporating tubes into the mix. Only a consequence of a component design when it suits the need.

[leonski]

I'm sure such a circuit didn't generate ANY RF Hash at all.....

Don't forget? For a tube amp, you neee heater current AND B+
Heater is in th amps range while the output tubes.....IF you want even a 35x2 EL34 amp? Yet MORE heater current....