I´ve been into SS power switchers ever since the 1970´s, finally into tram and train drives. Things have prgressed rapidly since then and I use PFC into my tube amp supplies. You are quite right to be sceptic regarding the schematics. I´d want to see watchdogs; proper power up sequencing and various other functions, and EMC measures before taking someone elses unknown on. That last bit is the warning shot.
Reliability with SMPS with a high component count must also effect the MTBF (mean time before failure) and if it does go wrong, then what ? It will take quite a seasoned learning curve to suss out, not entirely without dangers and the reasons for failure.
Take care.
BBaron
Yeah, but EMC stuff and shielding will swallow much space. Running an FM tuner closeby is a good check for increased noise. Have fun!
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I like the convenience of using this SMPS but I wouldn't be happy if it went through multiple hiccup cycles every time I turned the amp on or if it shut down due to a solid bass transient. So I'm happy that it works with my circuit.
If I had those issues I would be experimenting further in hopes of eliminating them but, as always, YMMV. Perhaps you find them acceptable.
If not, I'd start with reducing the cap value significantly or even eliminating it. I'd also try wiring the heaters to run off the 6.3v output since my experiments seem to show that using the 12.6v requires you to either turn the voltage down or endure repeated hiccups.
I'm guessing that the higher current draw (200mA vs 100mA for my SE circuit) is not the issue.
Agreed, 400 would be better for 6L6/EL34/KT88s. Having said that, with triode-strapped tubes, especially sweep ones, 350 is already a lot. You can get plenty of power with a couple of EL36/EL504/509 etc.
The fact that it's only on power up, and that the amp needs to be at full power to the point of clipping to drop out doesn't bother me - it's the lowest power amplifier I've built.
What would be nice is if somebody made an SMPS with 12V @ 20A and 300V - 400V @ 2A - Then it would power a PP 6P45S amp
From what I've seen using the 6.3v tap instead of the 12.6v to heat the tubes will likely eliminate the hiccup issue. But maybe you don't want to bother with changing anything.
What about an ATX PSU + this thing? Rated at 1KW, 300V/2A is close to the Aliexpress' special 50% power ratingThe fact that it's only on power up, and that the amp needs to be at full power to the point of clipping to drop out doesn't bother me - it's the lowest power amplifier I've built.
What would be nice is if somebody made an SMPS with 12V @ 20A and 300V - 400V @ 2A - Then it would power a PP 6P45S amp
I designed my boards to use 12V since it's far more common - the heaters for 6P43P run in series, the 6F12P runs off of a 7806. So I can't really use the 6v3 output.
I have one, and I've used it to power a PP 6P45S amp. It would just be nice to find a one PSU solutionWhat about an ATX PSU + this thing? Rated at 1KW, 300V/2A is close to the Aliexpress' special 50% power rating
The real challenge is the switching topology over say 350V, hard flyback (the simplest of classic glass TV) can take to whatever voltage but is peak power restricted to 100W, creates rancor amounts of interference and challenges current SS devices available. There is aslo the reliability issue. Going into soft zero switching and other switching topologies is an expensive knowledge bump but where´s the real market for Hi end Audio ? The low voltage high current isn´t an issue, What is an expensive issue is the interference compliance and careful neutralization of chassis charged spikes from mosfet substrates and layouts. It is often a lack of design foresight in these issues coupled with poor dv/dt layouts that cause many problems and poor reputation.
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