Somebody, somewhere, someday will pass a law making amplified music illegal. Period. Because ANY of it would be considered a waste and potentially offensive to neighbors in earshot. And it is far easier for governments and commercial entities to control both licensing and content if EVERYTHING is streamed over the internet. Hope we have more than about 30 years left before it hits the fan.
How many hours per week is your class A amp turned on? How much power does it draw? If I compare that power which is actually being used, to that is wasted by my wife leaving lights and the TV on for hours even though she may be outside, the waste is insignificant. After 30+ years of turning them off only to find them back on, I have given up.
Many years ago I designed a high efficiency class A amp. The output stage was still a single ended tube, but it's power supply was modulated in a manner similar to that in a class H solid state amp. It got little interest at the time despite being published in a popular electronics maker magazine, so I forgot about. Perhaps it's time has come?
Many years ago I designed a high efficiency class A amp. The output stage was still a single ended tube, but it's power supply was modulated in a manner similar to that in a class H solid state amp. It got little interest at the time despite being published in a popular electronics maker magazine, so I forgot about. Perhaps it's time has come?
Of course I don't want to be a party pooper but in the same hours that the class A is switched one could have used a class D amplifier. Just saying. It is a little bit the same with the EU government forbidding vacuum cleaners above 900W as they think we vacuum the houses 24/7. Still, less power consumption is a theme that will stay on the agenda.
* After having seen the vast make-up, clothing and jewelry industry in China I am convinced women have larger carbon footprints. In fact, I started to believe whole industries are created for female clients.
Now that is something totally 2021!
* After having seen the vast make-up, clothing and jewelry industry in China I am convinced women have larger carbon footprints. In fact, I started to believe whole industries are created for female clients.
Now that is something totally 2021!
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Class D doesn't mean solid state only 😛
Just need some social media influencers to use class A and the price of NOS tubes will sky rocket.. Perhaps I should sell my vintage (post millennial) ecc99s 😉
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Hummmm, I'm reading a sepuku manual at the same time I re read the notice of my Chord SPM1000B amp... smps, but 400W at 4 ohms ! OK I can sleep, it's not if I had an electro magnet speaker with its power supply always on 😀
guys, try to watch Bright Green Lies tv...
guys, try to watch Bright Green Lies tv...
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Ok, I get it now looking at it - output stage is a k-follower. That would mean a custom (or at least strange) OPT wouldn’t it? I guess you would use what all the 6C33C lovers out there use.....
The class they call this now is TD, as in tracking downconverter. Where the power supply is essentially a class D amplifier supplying DC with audio riding on it. Single polarity buck converters can be made to work without any ifs ands or blown mosfets (no dead time requirement, and the body diodes don’t conduct) so FAR easier than a class D amplifier. The article appears to date from 09 - isn’t that around the time I started hearing about those 14kW 1U Labgruppen PA amplifiers (that cost a fortune)? I don’t think they were the first TD-class amps, but were the first to call it that, and gain market acceptance in the pro audio world (Carver tended to blow up too much, and their earlier stuff was just regular class G o H). I don’t think anyone ever did a class A solid state amp with a modulated supply - and with tubes would certainly be a first. I have heard of people fooling around with solid state single ended class A using a switchmode current source load, increasing efficiency close to 50% (same as theoretical for choke loaded or transformer coupled).
I spent nearly two years developing a modulated buck converter for use in radio transmitters, back in about 2004. At that time the electric bill for Nextel, a small cellular carrier was almost $1 million a month just for the southeast region. As LTE came into existence RF power amplifiers needed better linearity, which usually means poorer efficiency, so some fancy power supplies. At the time I used an open loop buck converter since the duty cycle to output voltage curve is better than our power amps was.
As that project was winding down Microchip sponsored a design contest in 2006, submission due in 2007, featuring their new dsPIC chips. One of the category prizes was "best use of the chip's SMPS features. I aimed my PIC powered tube amp squarely at that prize, applied what I knew from the cellular world, and got it.
The amp used a pair of Eastern Audio 600 ohm SE OPT's that I bought used from a forum member here. I was squeezing nearly 30 watts out of a single 6AS7 due to the efficiency improvement. it sounded pretty good too.
I robbed the amp for most of its parts, but the boards are still in a box somewhere. I'm not sure what happened to the OPT's, but far better ones exist today.
The pictures show the amp, both boards and the first proto for the controller The blue board)
Attachments
FWIW, Bitcoin mining allegedly now accounts for around 0.5% of the worlds
total energy consumption. That is a staggering figure by any measure.
Class A amps are starting to look pretty green.
TCD
total energy consumption. That is a staggering figure by any measure.
Class A amps are starting to look pretty green.
TCD
Cryptocurrencies all took a hit today. Chinese banned it (don’t know the details yet)
I do keep seeing article titles about more efficient mining. At the moment it is the wild west.
dave
I do keep seeing article titles about more efficient mining. At the moment it is the wild west.
dave
Member
Joined 2009
Paid Member
I was surprised when Elon endorsed Bitcoin because of his green image and Bitcoin being VERY not green. Glad ro see he recently came to his senses.
We need more energy because as a civilization it ultimately limits our reach. We are but a newborn in terms of energy use today.
Kardashev scale - Wikipedia
We need more energy because as a civilization it ultimately limits our reach. We are but a newborn in terms of energy use today.
Kardashev scale - Wikipedia
So she was horsing around with drivers? In hindsight it's good you've well compensated for that. 😛