Digital Av Receivers Are Here

[Roderick]

Digital amplifiers seem to have got themselves a bad name from audiophiles, but some better ones are beginning to appear, and they sound pretty good by all accounts. In particular, the Panasonic SA-XR700, (~ AUD $1400) which has recently come on to the market as the natural partner for Panasonic's DMP-BD10 Blu-ray player, seems to be the leading exponent of the all-digital receiver.

Now many people will automatically write-off Panasonic Av receivers as cheap mass-market products designed for HTIB sets. Not so! Panasonic and Texas Instruments have sunk hundreds of millions of dollars into the development of the few chips that go to make up an all-digital amplifier, and they look like they may be about to reap the benefits in the form of relatively cheap amplifiers that are exremely efficient, weigh about 25% of an analogue amplifier, put our far less heat, and sound very good.

Some relevant links :-

http://www.panasonic.com.au/products/categ...m?objectID=3511

http://www.cnet.com.au/hometheatre/avrecei...39271169,00.htm

http://www.avsforum.com/avs-vb/showthread....286#post9001286

In particular, the last link from the US AV Forum is quite revealing. The SA-XR700 seems to have developed a bit of a cult following, with claims of superior sound to other popular receivers. The other Panasonic receicers -- such as the SA-XR57 (Powerhouse ~ AUS $700) -- also seem to have had quite a following over the last year or two.

The main benefits as I see them are :-

Very clear sound resulting from distortion-free amplification.

Background sound levels that are virtually complete silence

The ability to automatically assign 3 amps per chanel to stereo output (tri-amping)

Extreme electrical efficiency (~90%) and very low drain when no sound

Little heat given off

Weight that is about 25% of a comparable analogue amplifier

Small size -- they fit in my current entertainment unit!

Of course, all is not completely roses, and if you read some of the above links you will find there are other deficiencies to these amplifiers -- none of them insuperable. However, I predict that receivers such as these will begin to take over, not just in the mass market, but in the audiophile market as well. it may take a while, but the writing is on the wall. Digital amplifiers can be made cheaply, with less material used, with a much lower CO2 profile and a sublime sound. The qualities of the amplifier are largely determined by software, not hardware.

I'd be interested to hear from forum members about other digital amplifiers. I noticed a JVC digital amplifier the other day, but know nothing about it.

Feel free to fire away!

Rod

[joz]

Seems your very excited Rod,fair enough too. Though I will reserve my judgment at this stage and just let things run their course.

[Nevyn72]

Give it a little more power, say 120W per channel, HDMI 1.3 (for higher spec audio) and upcoversion of inputs to HDMI and it looks like a contender.....

[Roderick]

Give it a little more power, say 120W per channel, HDMI 1.3 (for higher spec audio) and upcoversion of inputs to HDMI and it looks like a contender.....

Don't forget, Peter, that the criteria are different for digital amps. It's a new ball game. Clipping does not occur and big toroidal transformers are no longer needed. The power equation may be different, and the critical factors are in a language that is foreign to analog amps. Software comes into it in a big way.

Being able to switch multiple amps on the fly to where they are best deployed is a tremendous advantage. In effect, the SA XR700 puts out 300 watts per chanel in stereo mode. Real punchy, so they say.

Later amps will undoubtedly be better. I'm looking to getting an HDMI 1.30 AVR in about a year's time. Prices should be better, too.

Rod

[joz]

So how big is this transformer that can output 300watts per channel by two?.

Sorry I can't help but be sceptical.

Though a few years ago it was a Bel Canto Digi amp that gave me a hard on,today I have chosen solid state.

I'm not knocking their future as a viable solution,its just I believe the technology needs maturing.

[Roderick]

So how big is this transformer that can output 300watts per channel by two?.

Sorry I can't help but be sceptical.

Though a few years ago it was a Bel Canto Digi amp that gave me a hard on,today I have chosen solid state.

I'm not knocking their future as a viable solution,its just I believe the technology needs maturing.

Digital amps don't use transformers -- they're switch mode.

Rod

[joz]

No wonder they're lite.Though I couldn't remember the Bel Canto being like this?Anyhows I can't remember?

I remember reading quite a bit about the stuff afew years back,but have lost interest for awhile now.But will be sitting back observing the progress as it unfolds.

[Roderick]

No wonder they're lite.Though I couldn't remember the Bel Canto being like this?Anyhows I can't remember?

I remember reading quite a bit about the stuff afew years back,but have lost interest for awhile now.But will be sitting back observing the progress as it unfolds.

Yeah, the joz, I think most people have yet to grasp the significance of these developments.

Since digital amps are largely under the control of their software, it raises the possibility of changing the sound qualities of an amp to suit your tastes. You may be able to reprogram them.

The main consequence, though, will probably be cheaper AVRs and amps, without sacrificing sound quality.

Less material required, cheaper to manufacture.

Rod

[Razr]

Have you found any real specifications for this reciever?

My experience with "conventional" digital amps isn't that fantastic.. High THD's (0.1% is good for class D), poor damping factrs (40'ish is typical for class D, 400 is typical for mid-range analogue, and 1000+ in the top end), and really poor handling of higher frequencies (THD is frequency dependant with class D).

Still, this could be a whole new ball game, but I have to admit the statements like "degradation-free amplification" (which just smack of marketing BS) don't inspire much confidence.

[Hydrology]

Have you found any real specifications for this reciever?

My experience with "conventional" digital amps isn't that fantastic.. High THD's (0.1% is good for class D), poor damping factrs (40'ish is typical for class D, 400 is typical for mid-range analogue, and 1000+ in the top end), and really poor handling of higher frequencies (THD is frequency dependant with class D).

Still, this could be a whole new ball game, but I have to admit the statements like "degradation-free amplification" (which just smack of marketing BS) don't inspire much confidence.

I concur. At this point in time I feel that digital amplification done right seems to be at the higher end of the market. Of course over time the quality and price of digital will improve, but for now I have no problems with Class AB. My philosophy, if it aint broke, dont fix it!

[Roderick]

Have you found any real specifications for this reciever?

My experience with "conventional" digital amps isn't that fantastic.. High THD's (0.1% is good for class D), poor damping factrs (40'ish is typical for class D, 400 is typical for mid-range analogue, and 1000+ in the top end), and really poor handling of higher frequencies (THD is frequency dependant with class D).

Still, this could be a whole new ball game, but I have to admit the statements like "degradation-free amplification" (which just smack of marketing BS) don't inspire much confidence.

No, razr, I'm just going on what they say on the US AV Science Forum, where the comments are mostly very positive re clarity of sound. I saw the Panasonic SA-XR700 in 'The Good Guys' the other day, but was not able to audition it. If I'm about to make any purchase, I'll make damn sure I let my ears do the talking, so to speak!.

One thread on the AVS Forum (lost it for now) had a lot of comparisons between one of the Panasonic digital amplifiers (the XR57 I think) and most other populat AVRs. Most comments were very positive. I remember one comment was the Yamaha 2700 sounded "muddy" in comparison. Some think the XR700 is a bit too bright.

I don't think distortion is much of an issue with the XR700 though. Most people comment on its clarity and tight bass.

Rod

[Nevyn72]

Can be bought here for $1029

[ozcal]

Can be bought here for $1029

Hey Roderick , Digital amps have been around for quite a number of years now and the Panasoincs have been well recieved on a cost/perfromance basis.Sony use 'digital amps in all their current ES series recievers and having heard a few I have to say they sound rather good however the trick with all these things is not to get carried away with the technology and just see how they compare in the real world.

Reading between the lines of many of the reviews of both the low end stuff ,like the Panasonics and the higher end gear like the 3 relatively new Rotel 'digital' poweramps it seems that the victory is not wholesale with a large number of folk who can accomadate the much larger and less efficient 'analogue' amps preferring the sound quality.The comment I see repeated time and again is " if space is tight then these, the digital amps , do a great job but if you can accomodate the analogue designs they still do a better job in terms of sound quality.

Gordon

[Roderick]

Can be bought here for $1029

Thats more like it, Peter. The Panasonic SA-XR57 can be had for ~$700, so the XR700 was looking a bit expensive in comparison. There is not actually that much difference between them -- same size, channels and power.

I suppose the XR700's main claim to fame is that it will be the obvious choice of a digital AVR to go with the PlayStation 3 and it's Bluray player. The cheap way in to Bluray! Its HDMI 1.2 input can connect it to the PS3.

Panasonic will expect to sell a lot of them when the PS3 comes out, so the price may yet come down quite a bit.

Rod

[Cody]

Sony use 'digital amps in all their current ES series recievers

are you sure about that gordon? i have never seen/heard anything about the 1200ES / 3200ES / 5200ES being digital amps? The TADA9000ES was their first digital amp (now discontinued) and the only other I was aware of is the 7100ES, which is apparently still available although very old now and seemed to have pretty much all bad reviews regarding its power. as such i though sony had now dumped digital amps.

have to agree though, its not about the technology, its how good it sounds thats important.

[momaw]

While still a great amp, even the Harmon Kardon Digital Amps are considered inferior to their traditional amps.

[betty boop]

roderick there is nothing indeed new about digital amplifiers. if you do a search you'll find them discussed on here as far as I can remember certainly as long as I've been on this forum. And the technology goes long before that.

I think there is much confusion amongst us re digital amps. and that quite apparent reading some of hte comments in this thread. I dont claim to know all in this regard, I'm not an electrical engineer in consumer electronics to understand all the workings.

But do know some things...

the tact digital amplifier has a dirty great big torroidal inside.

The HK AVR2005 'digital' avr that uses the 'digital' ice module runs as hot as any other AVR in the HK range.

The original tada 9000es sony avr was a big mutha - so much for slim and compact

the nuforce and belanto digital amps have a some good rep in regards sound quality. They are compact but cost about the same as analog counter parts.

the nuforce amps have been known to put out high amounts of RF and EM intereference.

People call them digital amps but infact theyre just class D.

analog amps have been around a long time they are tried and tested implementaions and there is much range to choose from that produces excellent results.

I havent done extensive comparisons between digital amps and their analog price equivalnets.

They might be more efficient in amplification from analog amps but you still cant output more power than what power the amps consume and have a power supply to support.

I'm with gordon in that dont let the technology get in the way. just becasue its digital doesnt mean its crap but alos jsut because its digital it doesnt mean its cool. Compare for your self and buy whatever suits you best.

DG re the current sony es amps, wilco who sells them did a bit of an expose of them a while back. tunlike the previous ES range like the TADA, these current models do not deserve to carry the ES name.

[Razr]

No, razr, I'm just going on what they say on the US AV Science Forum, where the comments are mostly very positive re clarity of sound.

Cool. Who knows what they're comparing it to, but at least there's no-one out there saying it sounds like mud

Some think the XR700 is a bit too bright.

That's interesting - it either means that the receiver doesn't feature "degradation-free amplification" (quote from CNet link), or the people putting forth these comments ar giving it imaginary sound quality attributes. I suspect a bit of both

Anyways, it remains an interesting area. Class D does have some major effeciency advantages over class AB and especially class A, it just has never rivalled the SQ of either before. If this is changing and class D can actually be competitive with the better AB's/A's I'm all for it. Viva la revolution!

[Roderick]

roderick there is nothing indeed new about digital amplifiers. if you do a search you'll find them discussed on here as far as I can remember certainly as long as I've been on this forum. And the technology goes long before that.

etc, etc .....

Good to see I've stirred up some activity -- the Forum was getting a bit boring .

I realise digital amps have been around a long time and that there are many variations. I also know that many Class D switching amps are not really digital, but rely on substantial analog circuitry.

However, the logic behind fully digital amps has a certain inevitability about it, even if the realisation is taking some time. The experience todate may not have been all that wonderful, but the economics behind it all is driving digital towards an ultimately dominant position. And the products are getting better. The concensus on the XR700 seems to be that the sound quality is quite good -- a distinguishing feature even. It is let down in a few other areas, that could easily be fixed in time. The similar XR57 is widely acknowledged as being very good value for money, with better sound than most similarly priced AVRs. Most people like the sound it makes.

What is inevitable about digital amps is the control they give the designer. If something is not right in a digital amp, then the chances are it can be fixed by software upgrades. If you don't think a digital amp can achieve this sort of control, then just look at how far digital music has come in the last 20 years.

The economics of all this means that the hardware for digital AVRs -- i.e. the chips -- will probably be mass produced by just a few large companies. The AVRs can then be put together by many smaller companies, with the distinctions being built into the software, rather than the hardware.

Amps are becoming more like PCs, and their sound will get better in time. You betcha!

Rod

[sold]

Company that does full digital amps here - http://www.pulsus.co.kr/english/technology/tech_01.html - and a bit more info here - http://www.postech.ac.kr/e/newsletter/00fall/pulsus.html

[ozcal]

are you sure about that gordon? i have never seen/heard anything about the 1200ES / 3200ES / 5200ES being digital amps? The TADA9000ES was their first digital amp (now discontinued) and the only other I was aware of is the 7100ES, which is apparently still available although very old now and seemed to have pretty much all bad reviews regarding its power. as such i though sony had now dumped digital amps.

have to agree though, its not about the technology, its how good it sounds thats important.

My bad , just had a thorough look at the Sony OZ and Sony UK websites and there is no mention of 'digital' amplification on any of the amps you mention.The previous range of Sony ES recievers used the S-MASTER PRO , digital amps , this I know because I got one for one of my mates :ES3000 I think.It actually sounds very nice in his house.Looks as if Sony have gone back to using more conventional amps in most of the new ES series.

Gordon

[ozcal]

Good to see I've stirred up some activity -- the Forum was getting a bit boring .

I realise digital amps have been around a long time and that there are many variations. I also know that many Class D switching amps are not really digital, but rely on substantial analog circuitry.

However, the logic behind fully digital amps has a certain inevitability about it, even if the realisation is taking some time. The experience todate may not have been all that wonderful, but the economics behind it all is driving digital towards an ultimately dominant position. And the products are getting better. The concensus on the XR700 seems to be that the sound quality is quite good -- a distinguishing feature even. It is let down in a few other areas, that could easily be fixed in time. The similar XR57 is widely acknowledged as being very good value for money, with better sound than most similarly priced AVRs. Most people like the sound it makes.

What is inevitable about digital amps is the control they give the designer. If something is not right in a digital amp, then the chances are it can be fixed by software upgrades. If you don't think a digital amp can achieve this sort of control, then just look at how far digital music has come in the last 20 years.

The economics of all this means that the hardware for digital AVRs -- i.e. the chips -- will probably be mass produced by just a few large companies. The AVRs can then be put together by many smaller companies, with the distinctions being built into the software, rather than the hardware.

Amps are becoming more like PCs, and their sound will get better in time. You betcha!

Rod

Haven't we been through all this already Rod I don't necessarily disagree with the ecomomics of what you are saying but and it is a big BUT, there is a huge difference between theory and implementation otherwise a $49 cd player would sound just as good as a$4900 one and imo it's not just the analogue output stages of the more expensive cd players that make all the difference.

Many folk with hi-end systems still prefer valve over solid state sound never mind analogue vs digital amps.Each new technology brings with it ,it's own set of pros and cons and seldom is their a clear cut sound quality advantage in overall terms , all you can do is sit down and make an evaluation based on your own requirements.

The lower end of the market is more technology rather than quality driven imo , the lowend 'digital' amps are probably cheaper to make than their analogue equivalents as they don't require two of the most expensive components in any amp ie a quality transformer and a big case and it is my oppinion that this is what is driving inexpensive digital amps into the market rather than any real or percieved sound quality advantage ie more profit for the manufacturer ,not lower consumer prices.

Gordon

[RodN]

There have indeed been digital amps for a long time. There was a frew Pana XR advocates on here for quite a while. 2 very respected digital amps:

Halcro voted "best amp ever" by stereophile - absolutely world class amp and aussie made.

Crown K series - highly respected digital amps (with damping factors of over 3000) that have been running professional loudspeaker systems for many years as well.

I've had a few cursory listens to the pana's and sony digital amps and agree that they are well worth a demo - very 'clean' sounding.

[Roderick]

Haven't we been through all this already Rod I don't necessarily disagree with the ecomomics of what you are saying but and it is a big BUT, there is a huge difference between theory and implementation otherwise a $49 cd player would sound just as good as a$4900 one and imo it's not just the analogue output stages of the more expensive cd players that make all the difference.

Many folk with hi-end systems still prefer valve over solid state sound never mind analogue vs digital amps.Each new technology brings with it ,it's own set of pros and cons and seldom is their a clear cut sound quality advantage in overall terms , all you can do is sit down and make an evaluation based on your own requirements.

The lower end of the market is more technology rather than quality driven imo , the lowend 'digital' amps are probably cheaper to make than their analogue equivalents as they don't require two of the most expensive components in any amp ie a quality transformer and a big case and it is my oppinion that this is what is driving inexpensive digital amps into the market rather than any real or percieved sound quality advantage ie more profit for the manufacturer ,not lower consumer prices.

Gordon

Yes, I've seen some similar earlier contributions, Gordon, but I don't think we have heard the last word yet. Digital will slowly, but surely, overtake the current wisdom.

I've no doubt many people like the current class A and A-B amplifiers precisely because they are big and heavy and inefficient status symbols. I suspect it will take them a long time to go away, but go they will. Just as surely as steam trains (still some around though!).

As for valve amplifiers, I hear that in properly-run blind tests, the rate at which the valve amplifiers are correctly picked over solid-state ones is no better than pure chance. I remember helping my brother build a valve amplifier (mono) in the 1950's -- shows how old I am!

In the end, digital will dominate because it will become a better proposition all round. Perhaps we can have this conversation again in 10 years (hope I'm still alive!) and see how much the ground has shifted.

Rod

[betty boop]

There have indeed been digital amps for a long time. There was a frew Pana XR advocates on here for quite a while. 2 very respected digital amps:

Halcro voted "best amp ever" by stereophile - absolutely world class amp and aussie made.

Crown K series - highly respected digital amps (with damping factors of over 3000) that have been running professional loudspeaker systems for many years as well.

I've had a few cursory listens to the pana's and sony digital amps and agree that they are well worth a demo - very 'clean' sounding.

all good points there nobby, jsut a correction though. The halcro dm58 mono bloc declared as "best amp ever" by stereophile is very much analog. perhaps your thinking of the lyras class D modules that halcro makes for their HT range. All their 2ch power amps though are pure analog.

have heard the crown k series used as a 2ch amp and it put in a good performace. Though havent heard it compared to anything else say to make any comparitive comment. the crown I noticed ran very hot and a big heavy thing also with a dirty great big power supply.