[Patrick Turner]

wrote:

Hi group:

Has anyone in the group found a switcher good enough for high voltage (180
VDC), low current (.010 amps)
audio use. When I say good enough, I'm referring to noise and EMI. I've been
looking at LT, National and power integrations
but haven't found anything yet. I also need 12V @1.0 amp for filaments.
Any ideas appreciated.

RonL

I have been on the lookout for a SMPS for a tube amp capable of
+500Vdc at 1 amp dc for larger style tubed power amps.

I've never seen or heard of anyone doing a SMPS with that specification,
and not seen any schematic for one that I could for build myself.

Phil says follow the lead of what is done in CRO PS but then they are
low power output type supplies where the voltage is more important than
having any current ability.

Halcro of South Australia make fabulous solid state amps capable of
200 watts into 8 ohms and they use SMPS which are well filtered and
shielded or course,
and such techniques have been routine in TV sets and many apps for maybe
20 years,
so much so that the SMPS is a lot cheaper and lighter to carry than a
heavy
linear PS with a massive tranny, even if its a toroidal type.

Perhaps doing a SMPS for +1,100V B+ and -200V for the bias B- for
an SET 845 based amp may present problems, but then problems are there
to be overcome,
and so just why not have SMPS for high powered tube audio??

No need to tell me about filtering and casework; I know that has to be
good,
but what about an actual schematic with full specification of parts
including
recipe for the HF tranny??

I suppose someone is going to say well why use tubes
when solid state and low voltages are so much easier.
My answer in advance is that such recommendations will
never be adopted on a tube discussion group, and we would still want
to know how to do a HV SMPS.

Patrick Turner.