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Has anyone used this component to interrupt mains 220V trafos?
Has anyone used this component to interrupt mains 220V trafos?
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I read on another diyAudio thread that one is supposed to short the inputs on a power amp, when setting bias and DC offset.
That's the first I've ever heard of it - and I certainly didn't, with my AN4Rs. Did any of you do this ... or is it yet another piece of "advice" on the Internet?
That's the first I've ever heard of it - and I certainly didn't, with my AN4Rs. Did any of you do this ... or is it yet another piece of "advice" on the Internet?
Hello, this is not an internet tip 🙂. In theory by short-circuiting the inputs, you ensure that the signal is "0" and no noise sneaks in since some measurements are made at amplifier repose.
In practice, I have found no variation in the measurements, one way or the other, as long as the signal input is not touched, fingers of the hand for example. In fact, if you read any technical manual of amplifiers from the seventies, it already indicates this operation.
Greetings
In practice, I have found no variation in the measurements, one way or the other, as long as the signal input is not touched, fingers of the hand for example. In fact, if you read any technical manual of amplifiers from the seventies, it already indicates this operation.
Greetings
I think these are used in a lot of generic class A soft start circuits that also will shut down the supply at a given temperature.
I would've thought an all-SMD version would take it out of the comfort zone of most of the DIYers this is circuit aimed at.
(I had enough trouble with the few SMD components that are used - I certainly wouldn't have built it, if all SMD components were used!)
You mean disposable mass produced in china destined for landfill?
You must take care with smd resistors on power amplifiers, so some of them would be thru hole.
Good comment on landfills. We can't have AN39s squandered in trash bins, sacrilegious.....
HD
Good comment on landfills. We can't have AN39s squandered in trash bins, sacrilegious.....
HD
When I worked on an SMD version of Mooly's 100W LatFET amp, two considerations came into the design considerations. Power dissipation is an obvious one. The other less obvious one was voltage rating, with +/-45V rails in play that means you have to consider potentially having 90V across a resistor. That meant using 1206 size resistors rather than (usually for me) 0805 sizes. Where SMD resistors weren't viable were the likes of 0.22ohm 5W values in use in the o/p stages, Thiele and Zobel networks.
I did already buy the PCbs from x which are beautiful and very nice. It just occured to me that this has the potential to be an extremely small form factor amp with the active cooling and remote mosfets. I'll probably start working on one.
I personally dislike the disregarding of Chinese components. There are poor quality products made everywhere. I have had wonderful experience with Chinese made electronics, components and tubes. This is all destined for the landfill eventually.
I think I can assume the majority order our PCbs from China at very least. If it's good enough for the foundation why not build with it.
I personally dislike the disregarding of Chinese components. There are poor quality products made everywhere. I have had wonderful experience with Chinese made electronics, components and tubes. This is all destined for the landfill eventually.
I think I can assume the majority order our PCbs from China at very least. If it's good enough for the foundation why not build with it.
All my commercial pcbs are made in China, and far better quaity than I could get it Australia as the industry here is almost defunct.
I have always found the Chinese products to be variable; you can buy very low quality, but also high quality too. Significantly, until recent (political) times, Fairchild made most of their semis in China. China is the world's factory, although they are battling economic winds at present, and deserve respect for bringing 90% of the population from agrarian poverty to urban working class in only 50 years.
C60Hz, good luck with your build. The AN39 is a superb amplifier if I do say it myself. A local friend, AndyR, built a 4R version and in my view it is the best sound system I have ever heard, and at 73 I've had a few in my many summers.........
Cheers,
Hugh
I have always found the Chinese products to be variable; you can buy very low quality, but also high quality too. Significantly, until recent (political) times, Fairchild made most of their semis in China. China is the world's factory, although they are battling economic winds at present, and deserve respect for bringing 90% of the population from agrarian poverty to urban working class in only 50 years.
C60Hz, good luck with your build. The AN39 is a superb amplifier if I do say it myself. A local friend, AndyR, built a 4R version and in my view it is the best sound system I have ever heard, and at 73 I've had a few in my many summers.........
Cheers,
Hugh
I have no idea, Adason. I need to email XRK/Mark to find out when, it's worrying me a little.
Others here are asking the same question; they want to compare it with my Titan and Maya at my home!
Hugh
Others here are asking the same question; they want to compare it with my Titan and Maya at my home!
Hugh
Hugh, if you are happy with the performance, why need others to approve, you have designed amps before some has been playing with toys. No disrespect meant, just your experience far exceeds most. You must have realised by now, nothing is better only different. You already confirmed it is the best you have heard and that is what it is about.
Actually, Nico, I'm not too concerned about what others think about my amps, I know they are good, but I do need to market them.
That has always been my greatest difficulty, particularly from a small populated remote island like Australia!
The other issue is that my philosophy is so different to the most zero THD guys that my views are anathema and I'm a bit over the abuse.......
Thanks for the post, why don't you send me emails you old bugga?
Hugh
That has always been my greatest difficulty, particularly from a small populated remote island like Australia!
The other issue is that my philosophy is so different to the most zero THD guys that my views are anathema and I'm a bit over the abuse.......
Thanks for the post, why don't you send me emails you old bugga?
Hugh
(anathema)
it is Greek word i think....hahaha ..
Your amplifier Alpha Nirvava it is one of best.....let them others with low THD to say words....we listening sound....not numbers
80 watts of power dissipation plus signal leveling, the little rascal can't take it - guaranteed!
I already have cuffs on the Bub and his sister Babe - the TO couple can just about cope with the thermal stress there. AN39 is a completely different beast.
have fun,
HBt.
Why BJT? - we are building push-pull MOSFET power amplifiers here.
No, NR ... sometimes different is better! 😵
For example ... my AN4Rs sound much better - compared to my Hugh Dean-designed 'NAKSA 80s' - driving the same 4R spkrs. (And before you say ... maybe the N80s can't handle 4 ohm spkrs - they were modified to be able tp cope with the Maggie 2 ohm ribbons I had before my latest spkrs!)
Yes ... it is the best! 👍