I'm referring to the period of around 2000 to about 2005, where many mid-fi manufacturers like Panasonic, Sony, etc came out with receivers equipped with "digital" power amp sections, which came withclaims of higher efficiency, lower heat production (not in my experience!) and other promising features.
But eventually these models seemed to be quietly replaced with receivers containing conventional class A/B amps. There are a few left with digital amps, like some of Pioneer's upper end Elite models and a couple Onkyo stereo integrated amps, but that's about it.
Thoughts?
But eventually these models seemed to be quietly replaced with receivers containing conventional class A/B amps. There are a few left with digital amps, like some of Pioneer's upper end Elite models and a couple Onkyo stereo integrated amps, but that's about it.
Thoughts?
My thoughts, which may be completely wrong! Designing a decent Class D amp is difficult and expensive. Therefore the easy way out is to use a chip, so the silicon designer has done the hard work for you. Then you are just a box assembler, and your amp sounds much the same as everyone else's - no unique selling point, no buzzwords for the advertiser. Having got this far, you then find that you need a good RF designer to do the output filter and PCB design, otherwise you fail EMC tests and can't sell into Europe etc. (unless you just tell lies and put an undeserved CE sticker on).
In the end you decide it is not worth the hassle. Cheap mass-market audio will use Class D chips, and not worry too much about EMC. The rest will use something else, including conventional circuitry.
In the end you decide it is not worth the hassle. Cheap mass-market audio will use Class D chips, and not worry too much about EMC. The rest will use something else, including conventional circuitry.
Nonetheless , most bottom-fi ,lo-fi and mid-fi 5.1 DVDs use them . And in a pub ,with soft music diffused by those tiny satellites ,in the background ,it could also not be so unpleasant to listen to.
But FM radio has to be Dtalized before ...😱
But FM radio has to be Dtalized before ...😱
Several standards for digital radio broadcasting are already technically ready and approved even in our conutry/EU.
The only reason why you do not see them around are bureucracy and lobbists (i.e. mobile phone companies.) It is more or less tha same reason for that you do not have WI-Max for internet.
In the UK 45% of radio listeners listen to digital radio (DAB).
At 128kbits the quality is abysmal but then the brits are used to listen to AM unless its the BBC who was pretty much the sole provider of FM broadcasts until well into the '80s.
Sorry, But I have to say it again ,MP3's suck,as far as quality is concerned.
It is okay for just hearing the song but it does not make my audiophile quality list.
jer
It is okay for just hearing the song but it does not make my audiophile quality list.
jer
45%? That may be the figure for people who have a digital radio somewhere in their house, but I think digital listening is less than that - and it probably includes internet radio too. Most British radio listening uses FM, and will continue to do so unless forced to change. Digital radio in the UK is a joke - unreliable signals, low bit rates and heavily compressed pop music, which is why so few people use it.
There is almost no connection between digital radio and 'digital' amplifiers, as the signal gets turned to analogue between them.
There is almost no connection between digital radio and 'digital' amplifiers, as the signal gets turned to analogue between them.
D amps are great for bass and stuff.
But they just haven't made that mark as super sounding yet otherwize they would be mainstream by now. jer
But they just haven't made that mark as super sounding yet otherwize they would be mainstream by now. jer
I agree the same goes for the DTV revolution as well I have yet to see any thing on common programing the surpasses what we used to get on analog tv.
But I can say that I am impressed with the 24bit audio format but it is marginal to analog.
That is just my opinion. jer
Class-D is great for venues, coupled with ethernet- og even glass-distribution of channel line-levels.
But thank God, that there is still room for venerable copper, tubes, Class-A that drives your wife nuts when the annual electrical bill gives room for all kind of excuses: "Hon, we need a new fridge, the old one has been sucking too much current this year"!
But thank God, that there is still room for venerable copper, tubes, Class-A that drives your wife nuts when the annual electrical bill gives room for all kind of excuses: "Hon, we need a new fridge, the old one has been sucking too much current this year"!
The numbers are from wiki and I know that digital radio has nothing to do with digital amps but I was indulging Pico who made that connection somehow.
Which is why I quoted him.
Sounds like a good theory to me - thanks.
As far as the heat issue I mentioned, one of the first class D receivers I listened to was a Panasonic SA-XR25. After playing some music via a pair of Bose 301s (that's what was hooked up at the Circuit City store at the time 🙂) at levels slightly louder than conversational levels, the rear top became as warm to me as a class A/B amp & the rear-mounted cooling fan was going full speed. Similar experiences with other brands of class D receivers followed. So despite all the advertised claims, I'm not so sure if efficiency was increased all that much over "old fashioned" amp designs.
I suppose we need to look at all the heat dissipated in a system, a 300VA 25V transformer "looses" nearly 30W in copper and iron losses... thats quite a handicap to start off from.
Oh ,yes ...sorry : I was thinking of another thing while writing about that .
I was talking about DSP ,like in car audio ,where the signal has to be in a numerical form to be processed .
That doesn't necessarily apply to dvd-receivers where ,as DF 96 marked ,there's a mix of the two ,and the signals is analogical at amp's input .
But the true DDD 😛 7 channels amps like Yamahas from the '90s and other brands are -yes- something of the past ,or really luxurious in these days .
I have to disagree.
Class D amps are every bit as good as class AB.
I have designed both and cant tell the difference between them.
I have to say that I am in the middle on that one.
But,I can say in order to get good quality with class d the design starts to become overly complicated for what it is worth.
Don't get me wrong as I like the technology very much.
But, I am a bit of an analog purist persay.
Givin the time I am sure it will become the norm one day.
jer
But,I can say in order to get good quality with class d the design starts to become overly complicated for what it is worth.
Don't get me wrong as I like the technology very much.
But, I am a bit of an analog purist persay.
Givin the time I am sure it will become the norm one day.
jer
I guess nobody here uses an iPod, and if you did waste your money on one, flush it down the toilet since it uses digital technology throughout.
I just use it as a remote control. My sons Iphone that is. Would never buy Apple anything. But that is beside the point. Since the OP was asking about power amps.
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