In Reply to: Ron, Switching PS for Filaments? posted by Glimmie on January 16, 2001 at 12:37:46:
A few audio companies are turning to switching power supplies. While they are generally not as good of a regulator in a dynamic environment, they are more efficent, thus their popularity in computers.But since filament supplies are more of a static load it would seem that a switching supply would be perfect for this application. The only thing you have to watch out for is the noise they can induce into an audio signal. Even though they may be switching at 100khz or more, they can still induce noise. For example, they can induce switching noise on the ground leg of your supply and this will get into your system. Therefore I would probably steer clear of the "cheap" surplus units and look for one with good specs.
I have a friend that was using one in his amp design and it appeared to be working well until he tried to bias up the filament supply for his SRPP driver stage, at which point, it introduced all kinds of noise.
But give one a try and let us know if/how it works.
Ron
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