M. Gregg wrote:
I found the answer but its not "cost effective". I used a charge pump and generated voltage 50V higher than needed then regulated with a Maida regulator followed by C/L HF filter.
Right. If I want to make a SMPS at 60 KHz, then I expect only to have to filter out 60 KHz. Part of the convenience of the SMPS is not needing to build a four-stage filter to get it all. This is also for a line-stage amp, where the ripple can be 1 mV or so without serious issues (the peak voltage from a line source is 500 mV). For a phono preamp or anything guitar-related, it's a definite deal-breaker.
I suppose that, should I have a big enough chassis and some high voltage electrolytics available, I could make a large filter to get ripple down in the sub-microvolt range so a phono preamp would be happy. To me, it seems like a better idea to choose a switching IC that doesn't present these problems.
The other part of my intent is to make a portable HF station using tubes. That is, a CW transmitter and receiver with a TRF or Regen detector (or both!). I don't want to put extra work into making a filter that adds bulk and weight. Not too good with cramming 10 pounds of electronic components in a 5 pound bag.
I would want to have dual supplies, though; one supply to make B+ (let's say 250 for this case) and another supply to make 6.3v or 12.6v for filaments. Since the battery is about 12v, what one could do is make a buck-boost supply that inverts your filament voltage, making -6.3 or -12.6v for the filament. Such voltage would be regulated well as the battery discharges, and having a negative voltage can also provide a way to bias your tubes if you need a C- supply.
Oh well. Much discussed. Some disgust. Time to hit the books again. Imma figure this out.
Ed