In general, SMPS’s are not crap, but many are. Cut corners, and you get garbage. An audio amp draws a continuously varying load, from near zero to a little over 3X it’s RMS power rating. A supply that can deal with that gracefully, and reliably, is expensive. Consumer electronics will cut corners, and typically you won’t get something quite as capable. The requirements for lighting ballasts aren’t as stringent. You can live with less ripple filtering. And the load is for the most part constant. Power requirements are only tens or maybe 100-200 watts for the big suckers (ie, HID replacements). So you can make a reasonably reliable supply cheap. But you do get a lot of garbage as well - the supplies in cheap LED light fixtures often burn out in a few years. Spend a little more and that typically won’t happen.
What is really needed in homes (perhaps businesses) is a standard 12 or 24 volt DC bus that is run in addition to the AC mains, specifically for small appliances with brushless DC motors and LED lighting. Maybe 500 watts or so. Need more, run multiple busses. A good highly efficient and highly reliable LLC converter could be used, installed at the breaker panel. It may cost $1000, but it’s something you would replace every 10 or 20 years. Simple buck converters could be used locally at the point of use, to step down to 5 volts when needed. Some sort of standard would need to be agreed on and adhered to, as far as voltage (range) and maximum power draw at any one device. Options for battery backup could also be written into the standard.
What is really needed in homes (perhaps businesses) is a standard 12 or 24 volt DC bus that is run in addition to the AC mains, specifically for small appliances with brushless DC motors and LED lighting. Maybe 500 watts or so. Need more, run multiple busses. A good highly efficient and highly reliable LLC converter could be used, installed at the breaker panel. It may cost $1000, but it’s something you would replace every 10 or 20 years. Simple buck converters could be used locally at the point of use, to step down to 5 volts when needed. Some sort of standard would need to be agreed on and adhered to, as far as voltage (range) and maximum power draw at any one device. Options for battery backup could also be written into the standard.
They also despise every other technology invented after the 1938 300B vacuum triode, correct?
Well, they've virtually replaced old-school power supplies in almost every consumer electronics product, so that says something, no?
At work, we have several old 60 Hz power supplies that can deliver 8 volts at 10 amps (80 watts). Each of them is about 45 cm x 15 cm x 20 cm, and weighs maybe 15 kg.
A typical modern switch-mode laptop power supply delivers about the same power (many are rated for 80 watts or more). I just measured an older HP laptop power supply, and it measured 10 cm x 4 cm x 3 cm, and weighs 160 grams. So this little beauty is one-tenth the volume, and nearly one-hundredth the weight, of the old-school 60 Hz power supply with the same output power.
As far as I'm concerned (and as far as most of the global electronic consumer industry is concerned), switch-mode power supplies are absolutely wonderful things. So much smaller, so much lighter, so much cheaper, and they deliver better quality DC, particularly when you need lots of current. What an incredible gift to anybody interested in electronics!
The only bad thing about them is that it's very hard to DIY one, so we have to buy them as "black boxes", and use them without knowing exactly what's inside. I had to get used to that many decades ago, when I first began using integrated circuits to build audio amps and preamps - ICs are "black boxes" too!
-Gnobuddy
I was thinking along similar lines when I wrote those posts about household LED bulbs. Something like this would make a lot of sense. Perhaps one day LED-friendly voltages will be incorporated into the wiring of new buildings as they're constructed.
Regarding SMPS and audio power amplification, most of the small music production studios have gone to powered monitor speakers during the last twenty years or so, and every one of these I've seen uses an internal SMPS. Depending on size and cost, the internal audio power amps may deliver up to 50 - 100 watts RMS to the loudspeakers, so the internal SMPS must be pretty beefy.
-Gnobuddy
Right now, I'm listening to a preamp and a power amp powered from a 850W 12V ATX computer power supply and several DC-DC boost converters. No noise. In fact, the buzz from the 60Hz power transformer from my only amp that uses an EI power xfmr is much louder than even the fan when it even spins.
I'm building a new integrated amp using the same idea. I'll start a thread when I get further.
My main problem with 60Hz supplies for LEDs is the damned flickering. I have a 100W LED flood lamp that I'm dying to make switch faster that bothers my eyes when I work. It does make the strobe edge of the turntable platter VERY easy to see to set the speed I can hardly even see the crappy little NE-2 they used.
I'm building a new integrated amp using the same idea. I'll start a thread when I get further.
My main problem with 60Hz supplies for LEDs is the damned flickering. I have a 100W LED flood lamp that I'm dying to make switch faster that bothers my eyes when I work. It does make the strobe edge of the turntable platter VERY easy to see to set the speed
I can hardly even see the crappy little NE-2 they used.LED's without power factor correction are very inefficient. I was asked to design a lighting retro fit at Children's Hospital when they wanted a led conversion from cfl's. I knew something was askew when the heat sinks for the down lights looked like they could dissipate 200W. Led's power supplies that are not designed correctly (most) end up putting a asymmetrical wave form back on the line as well.
25 years ago I installed my own central heating system. The rules were " a competent electrician/ gas fitter". Now it says "qualified". I know who I would rather trust.
Finding capable tradesmen that care anymore is a tall order, and the general public does not know/care either......Joe homeowners think they’re getting the best possible quality when they pay for a ‘professional’ to do things; Clueless that they themselves are part of the problem.
As a master craftsman who is dedicated to doing my best (given circumstances of course) it sickens me to see what passes muster these days.
As a master craftsman who is dedicated to doing my best (given circumstances of course) it sickens me to see what passes muster these days.
They are all installed in a grounded aluminium chassis. There is no noise on the power, and if there is RF coming from it, I can't tell since there is already so much RF in this place (the entire AM band is 60Hz)
Modern rubbish. 01As and #26s, here nothing as new as that!They also despise every other technology invented after the 1938 300B vacuum triode, correct?
Some of us didn't get that memo...….here you will see some 91 year old NX-483's running on an old school transformer / 5AR4 power supply. But in between those WE-417A's and those old NX-483's you will find a very modern CCS load and MOSFET buffer, since it is the best circuit for the job!
A well designed and executed SMPS can be a useful tool in the quest for good sound. However the knowledge and skill set needed to pull one off, especially at vacuum tube voltage levels, is not well understood by most of us in the DIY audio community, myself included, so I stick to what I know, and keep learning (and blowing up parts) until I CAN pull off a good SMPS.
A well designed and executed SMPS can be a useful tool in the quest for good sound. However the knowledge and skill set needed to pull one off, especially at vacuum tube voltage levels, is not well understood by most of us in the DIY audio community, myself included, so I stick to what I know, and keep learning (and blowing up parts) until I CAN pull off a good SMPS.
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I've just obtained a dual PPM, and need a power supply, and have been looking at 'wall warts'. They have both linear and SMPSs available at RS, but many more of the latter.
I already have a (mono), single PPM and built a linear one for that using an old 'wall wart' (screwed together), and arranged a new transformer and rectifier with switch and LED, but not really enough current for the dual one. (In any case I want them to both be usable so need another supply.)
This is to go in the back bedroom which is used as a singing cubicle with remote control of the studio downstairs.
I already have a (mono), single PPM and built a linear one for that using an old 'wall wart' (screwed together), and arranged a new transformer and rectifier with switch and LED, but not really enough current for the dual one. (In any case I want them to both be usable so need another supply.)
This is to go in the back bedroom which is used as a singing cubicle with remote control of the studio downstairs.
Parts Per Million? Pulse Position Modulation?
Somehow I have the feeling it's neither of those. What does "PPM" mean on an audiophile forum where a 300B triode is not old enough go get any respect?
-Gnobuddy
Sorry Peak Programme Meter, as in monitoring audio levels.
Very expensive ballistic movements and a sustained signal to ensure the needle gets there. Black background and white markings of 1 to 7, 4dB between each. Maybe not used to much across the water
Peak Programme Meter | eBay
Very expensive ballistic movements and a sustained signal to ensure the needle gets there. Black background and white markings of 1 to 7, 4dB between each. Maybe not used to much across the water
Peak Programme Meter | eBay
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Interesting. Never heard of it.
I think digital SPL meters are much more common here. That's what I use.
Oh. Wait. Is the PPM for measuring signal, or sound?
There are standards which slightly differ for the PPM in Europe, (scale) and Canada.
It is used for signal measurement and it follows, that it can be used for spl measurement.
Th BBC had a measurement tool called the 'AMP DET' which was used for all technical measurement, and went down to -70dB, with a 'listen' socket which gave zero level O/P for monitoring what was being measured. Of course -70 is not so good these days.
It is used for signal measurement and it follows, that it can be used for spl measurement.
Th BBC had a measurement tool called the 'AMP DET' which was used for all technical measurement, and went down to -70dB, with a 'listen' socket which gave zero level O/P for monitoring what was being measured. Of course -70 is not so good these days.
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