Yamaha AVR owners thread

[spirovious]

What are the power output claims of the 7.1 Yamaha RXV-677 & how much does it costs in India?

Yamaha 667 claims 90w/ch,but has only 400w power supply.Price with B/W in Mumbai is 39k & 37K in grey.

 

[rishiguru]

Yamaha 667 claims 90w/ch

90 w/ch at what impedance rating? 4,6 or 8 ohms. Also is this figure all channels driven or only one channel driven? What are the THD levels at 90 watts & also is this power attainable through out the audio frequency spectrum or just something like mass market @ 1kHz.

but has only 400w power supply.

are you figuring this amp have a 400 watts since it is written at the back of amp as a power consumption figure rating?

If so you are mislead. Many factors go into the power ratings, that make them pretty much useless for predicting power output. In most cases we don't know the test condtions so even assuming that the back panel power is nominal, average, maximum, minimum or whatever is nothing more than a guess unless it specifically says what it is. Country specific regulating agencies for the intended market region influence what number has to be used.

Take for example of the Yamaha M-80 power amp. For the very same amp there are four to five considerably different back panel ratings depending on the intended market region & country. The figures range from 600 watts all the way to 1300 watts for the same amp. But all of them pump out the same amount of power.

--------------------

What is the weight of this 667 amp? Weight is the biggest indicator of how much power the amp can pump out. You will find that expensive top of the range AVR's of a company have more or less the same features as the middle end models give or take one or two, but the weight of the amp drastically increases as we go to the upper range since the the power supply unit of the amp gets fatter & fatter to provide more & more power to the amp.

And nowadays never go by the power output claims of an audio manufacturer. Nowadays it is more or less like PMPO stuff. Go by the weight of the amp.

If it hovers at around 10kgs, it will have a 300VA transformer at max which will lead to 160 watts of usable power for all the 7.1 channels, ie 160/8 = 20 watts per channel with all channels driven simultaneously.

To give you a comparison my Yamaha DSP-A2070 7 channel amp have 350 watts of power consumption rating but still weighs 21kgs. It has an 800VA transformer, so you get at around 420 watts of usable power.

This is the truth my friend.

But still 160 watts of power with high sensitivity 7.1 speakers packages having 90db+ can produce really really loud sound. Remember our humble Norge 1000 integrated stereo amplifier weighs 8.7 kilos & also pumps out 160 watts of power & is deafining loud to say the least.

B/W in Mumbai is 39k & 37K in grey.

Price seems to be good.

 

[drkaushik]

Why no HD DTS sign in panel

My 667 shows DTS on panel when a DTS disc is played.Then why when HD dts disc is played it shows STRAIGHT?Can anybody clarify?

 

[Santy]

90 w/ch at what impedance rating? 4,6 or 8 ohms. Also is this figure all channels driven or only one channel driven? What are the THD levels at 90 watts & also is this power attainable through out the audio frequency spectrum or just something like mass market @ 1kHz.

@ 1 khz, it can output 140W per channel (we will not talk about this).
The specs otherwise: 105w/ch peak and 90w/ch continuous to 8ohm load.
However, since the power supply is only 400W, all channels cannot output 90w simultaneously.

But you need to first fully understand home theatre really works.
I cannot imagine any movie sequence wherein sound is recorded on ALL 7 channels at peak levels and a listener sitting in the centre with full volume on his AVR. This will be unbearable. Most surround sound recording uses the fronts and centre much more than the surrounds. Even cinema halls do not run their audio system at full volumes. You will probably never ever need the maximum power the AVR can handle, ie. 400W unless you have very low impedance speakers coupled with it or you listen to music in 7 channel audio mode at full volumes.

are you figuring this amp have a 400 watts since it is written at the back of amp as a power consumption figure rating? If so you are mislead. Many factors go into the power ratings, that make them pretty much useless for predicting power output. In most cases we don't know the test condtions so even assuming that the back panel power is nominal, average, maximum, minimum or whatever is nothing more than a guess unless it specifically says what it is.

It seems that you are quite confused. 400W is the maximum "electrical power" the unit can supply to the amp section. What you are talking about (mean/ nominal/ maximum ) is for the amp section. There is no nominal or average rating in power supply. This PSU can continously output 400W requirement at all times if necessary. How much power is derived from the PSU by the amp depends on the audio recording and the volume set on the AVR. However the Amp's power capabilities are limited by the PSU.

Go by the weight of the amp. If it hovers at around 10kgs, it will have a 300VA transformer at max which will lead to 160 watts of usable power for all the 7.1 channels, ie 160/8 = 20 watts per channel with all channels driven simultaneously.

For your kind information, the subwoofer channel is not amplified. So you must divide by 7 and not by 8.
Again I wonder why you have to do complicated maths to know how much maximum power each channel can handle- all continously. It is 400W / 7 = 57 w per channel. But it would never go to that extent. The AVR can output a healthy 90W whenever there is a demand. Assume you use 80W for the main channels ((fronts & centre) ie 80W x 3 = 240W and we still have a lot of power (160W) left for the surrounds. This is lot of power for an mid level AVR and this power is rarely used.

Above all, maximum power rating is not everything. There is much more to do with the amp which defines how good the sound is. What matters is how the amp makes use of the power and not how much it uses.

 

[rishiguru]

Again I wonder why you have to do complicated maths to know how much maximum power each channel can handle- all continously. It is 400W / 7 = 57 w per channel. But it would never go to that extent. The AVR can output a healthy 90W whenever there is a demand. Assume you use 80W for the main channels ((fronts & centre) ie 80W x 3 = 240W and we still have a lot of power (160W) left for the surrounds.

What is the weight of the amp? This figure will open all mysteries about its power output capability.

Also according to you if the power supply module of 667 is capable to deliver say 400 watts to the power amp module, there will be no heat loss and you will get 400/7 = 57 watts per channel. In other words a power amp with 100% efficiency.

Class-AB power amps have 50~55% effeciency at best & the rest 45~50% is lost as heat. This is the reason why amps get hot.

So we end up half of what you get from the power supply i.e ~210 watts at max from the speaker output terminals. Ee get 210/7 = 30 watts per channel with all channels driven. Still the light will be shown when i know the weight.

Do you have an engineering background? Just for interest. You define very well. Keep it up.:thumbsup:

Man i want to buy the patient of 667 power amp module.

Above all, maximum power rating is not everything. There is much more to do with the amp which defines how good the sound is. What matters is how the amp makes use of the power and not how much it uses.

Very well put. It is ultimately the sound quality that matters. But man always craves for more. Hence more power is a boon. Also high power amps will have huge dynamic headroom.

Anyway, 667 is a great AVR for its price. No doubt about that.

--------------------

@Santy one request.

You have both the Yamaha RX-V471 & Norge 1000. How do they sound in stereo mode with the same set of speakers. I mean which one do you like more to hear for music? And why?

Which amp will you call superior in terms of sound reproduction? Which amp has more power in stereo mode?

I will love to know all these details since I own a Norge 1000 too.

 

[Santy]

What is the weight of the amp? This figure will open all mysteries about its power output capability.

Also according to you if the power supply module of 667 is capable to deliver say 400 watts to the power amp module, there will be no heat loss and you will get 400/7 = 57 watts per channel. In other words a power amp with 100% efficiency.

Class-AB power amps have 50~55% effeciency at best & the rest 45~50% is lost as heat. This is the reason why amps get hot.

So we end up half of what you get from the power supply i.e ~210 watts at max from the speaker output terminals. Ee get 210/7 = 30 watts per channel with all channels driven. Still the light will be shown when i know the weight.

Do you have an engineering background? Just for interest. You define very well. Keep it up.:thumbsup:

I agree with you, there is a power loss in terms of heat due to inefficiency but I don't think class AB are that bad.. they must be around 75% efficient. I do not want to get into more details without sufficient knowledge. It needs more understanding especially when the 400W supply is AC and the amplifier extracts DC power!

However I am keen to know your formula of calculating actual power simply based on weight of the amp. The weight not just depends on the transformer but many other things inside it, especially since its not just an amp but an AVR. I also wish to know why do you think Yamaha is misleading us in giving wrong specifications??

The amplifier weighs around 10.5kg and yes I am an Engineer.

@Santy one request.

You have both the Yamaha RX-V471 & Norge 1000. How do they sound in stereo mode with the same set of speakers. I mean which one do you like more to hear for music? And why?

Which amp will you call superior in terms of sound reproduction? Which amp has more power in stereo mode?

I will love to know all these details since I own a Norge 1000 too.

Thanks for asking. There are two things to it: the DAC and the Amp. I have not checked the AVR with the output of Caiman nor the line out of AVR on Norge. In other words, if I am purely comparing the two amps, then I should have the same source/DAC in both the tests, which I have not done so far.

Having said that, for music, the stereo setup is much much better than Yamaha eventhough the AVR is considered to be musical. However I am not sure whether the DAC or the integrated amp is the main factor for this difference. I would give a 50-50.

 

[rishiguru]

I agree with you, there is a power loss in terms of heat due to inefficiency but I don't think class AB are that bad.. they must be around 75% efficient. I do not want to get into more details without sufficient knowledge. It needs more understanding especially when the 400W supply is AC and the amplifier extracts DC power!

However I am keen to know your formula of calculating actual power simply based on weight of the amp. The weight not just depends on the transformer but many other things inside it, especially since its not just an amp but an AVR. I also wish to know why do you think Yamaha is misleading us in giving wrong specifications??

The amplifier weighs around 10.5kg and yes I am an Engineer.



Thanks for asking. There are two things to it: the DAC and the Amp. I have not checked the AVR with the output of Caiman nor the line out of AVR on Norge. In other words, if I am purely comparing the two amps, then I should have the same source/DAC in both the tests, which I have not done so far.

Having said that, for music, the stereo setup is much much better than Yamaha eventhough the AVR is considered to be musical. However I am not sure whether the DAC or the integrated amp is the main factor for this difference. I would give a 50-50.

Eat this :

So Watts the Problem?

Gene : "I totally understand and respect the tradeoffs between amplifier power and features in budget A/V receivers. Heck just a few years ago, you couldnt get a 7.1 A/V receiver with HDMI 1.3a A/V processing and decoding for under $2k, now you can get them for under $500 with OSD support via HDMI no less. Thats progress!

What I do take issue with however is when a receiver company releases their next generation of receivers at the same price points with virtually the same operational features, but costs reduces the power supply in attempts to increase profit margins.

Lets take a look at the differences between two $549 Yamaha receivers as an example. Yamaha isnt the only brand Ive noticed this trend with mind you.

Yamaha RX-V663


Yamaha RX-V665


Yamaha RX-V663 | Yamaha RX-V665
Retail : $549 | $549
Power Spec : 95wpc x 7 full bandwidth | 90wpc x 7 at 1kHz
HDMI (I/O) : (2/1) | (4/1)
Component Video (I/O) : (3/1) | (2/1)
A/V inputs : 5 with s-video | 4 (composite only)
Digital inputs : 3 opt / 2 coax | 2 opt / 2 coax
HDMI Up conversion : Yes | to 1080p
HDMI Pass thru : No | Yes
Speaker a/b : A + B | A only
Dimensions (W x H X D) : 17 1/8 x 6 3/4 x 15 1/2 | 17 1/8 x 6 x 14 3/8
Weight : 26.2 lbs | 18.7 lbs

The upgrades for the new model (RX-V665) includes HDMI up-scaling to 1080p, HDMI pass thru to enable video when your receiver is turned off, and 2 more HDMI inputs. The downside is no s-video, one less optical input and a significantly reduction in power. When a receiver company rates their amp at 1kHz, this usually means a full bandwidth(20Hz-20kHz) measurement will be about 10-15% lower. Thus I suspect if we were comparing apples to apples, the RX-V665 would only output around 70wpc compared to the 95wpc rating of its predecessor. Of course with nearly an 8lb weight reduction and considering both receivers use linear A/B amplification, this also likely means the RX-V665 doesnt have the power reserves to drive multiple channels with as much poise and finesse as the RX-V663.

For the above example, the consumer must decide whether or not the upgraded features of the new receiver are worth the sacrifice in amplifier quality. I suppose it depends if the end user leans more towards emphasis of video features than audio. If they desire both and one day have intentions of adding external amplification, than doesnt this become a moot point?

Not always. From my testing of A/V receivers from various manufacturers, most of them simply slap preamp outputs on the back of their receivers for a marketing feature. It is a very inexpensive way to impress the unsophisticated user into being awed. They usually dont put decent op-amps that have enough output to drive external power amplification to its full potential without the internal preamp of the receiver first clipping and going into gross distortion. Remember these receivers are designed as a closed loop system to work optimally with their own internal components. If the manufacturer is cutting costs in the power supply of their product to offer you more features, its a safe bet they arent giving you a higher quality preamplification section to power an external amplifier.

Conclusion

Having done this job for some time now, Ive noticed this trend with many of the major brands over the years. Companies go through up and down cycles and as a result lose market share. As long as technology keeps evolving, manufacturers will do their best to cram in features of next generation products that were only previously found in their flagship models. While IC integration will trickle down technology, reducing production costs making it easier to achieve this, there will usually be other compromises in the lower end models to realize the feature count.

Finding that balance of basic performance compromises vs. relevant features is the equation that receiver manufacturers must figure out when launching their new platforms. It seems Yamaha has upset this delicate balance with their latest RX-Vxx5 series of receivers. We will be paying careful attention to this trend for all manufacturers during our product evaluations to recommend whether or not these new dream machines have the audio chops of their predecessors or if theyve got the tools to adequately drive external amplification for those looking for more power in their next home theater experience. Dont just run out and buy the latest model because its newer.

Stop and think if the model you currently have meets the performance vs feature balance that is right for your needs and how the newer so called improved model fits into that equation. All the features in the world cant replace clean undistorted dynamics which we believe makes up most of the WOW and magic in the newer HD audio formats."

Gene DellaSala Biography

The above content belongs to two of the Gene's articles as below:

Product Managing Receiver Platforms & Power Ratings

Trading Amplifier Quality for Features A New Trend with A/V Receivers?

 

[Santy]

Firstly please do not copy paste such huge content from some external site. It is considered to be impolite. If you think it is interesting, just give a link.

Secondly, you have copy pasted this article below my quote and I do not see any relevancy either to my quote or to the discussion.

Thirdly, I do not know what you wish to convey by this cut paste job. Yes, its evident from the article that there is a difference between actual power output between those two models but I thought your doubt was about the power capabilities of the 667 & newer series? OK if you believe this article is right, that 665 has effectively 70W/ channel @ 1 khz then how come you derived that 667 (which has almost same specs) cannot exceed 20W by your weight : power logic? Strange. hyeah:

Fourthly it is very clear that you are slowly trying to bring in your God Made Amplifier unfittingly into this thread which is considered to be hijacking. Please limit your halleluiah to your own thread and spare the owners of Yamaha AVR.

Finally, showing this difference in power between two models of a brand, as the main reason why an old amplifier which does not even process discrete multi channel audio is better than the new AVRs for true home theatre experience, is simply RIDICULOUS. Forget HD audio, what's a home theatre which does not have 5+1 discrete audio channels.

Anyway let the discussion please be continued in your DSP-A2070 thread and whoever wishes to hear your "old" stories will meet you there.

Eat this :

So Watts the Problem?

Gene : "I totally understand and respect the tradeoffs between amplifier power and features in budget A/V receivers. Heck just a few years ago, you couldnt get a 7.1 A/V receiver with HDMI 1.3a A/V processing and decoding for under $2k, now you can get them for under $500 with OSD support via HDMI no less. Thats progress!

What I do take issue with however is when a receiver company releases their next generation of receivers at the same price points with virtually the same operational features, but costs reduces the power supply in attempts to increase profit margins.

Lets take a look at the differences between two $549 Yamaha receivers as an example. Yamaha isnt the only brand Ive noticed this trend with mind you.

Yamaha RX-V663


Yamaha RX-V665


Yamaha RX-V663 | Yamaha RX-V665
Retail : $549 | $549
Power Spec : 95wpc x 7 full bandwidth | 90wpc x 7 at 1kHz
HDMI (I/O) : (2/1) | (4/1)
Component Video (I/O) : (3/1) | (2/1)
A/V inputs : 5 with s-video | 4 (composite only)
Digital inputs : 3 opt / 2 coax | 2 opt / 2 coax
HDMI Up conversion : Yes | to 1080p
HDMI Pass thru : No | Yes
Speaker a/b : A + B | A only
Dimensions (W x H X D) : 17 1/8 x 6 3/4 x 15 1/2 | 17 1/8 x 6 x 14 3/8
Weight : 26.2 lbs | 18.7 lbs

The upgrades for the new model (RX-V665) includes HDMI up-scaling to 1080p, HDMI pass thru to enable video when your receiver is turned off, and 2 more HDMI inputs. The downside is no s-video, one less optical input and a significantly reduction in power. When a receiver company rates their amp at 1kHz, this usually means a full bandwidth(20Hz-20kHz) measurement will be about 10-15% lower. Thus I suspect if we were comparing apples to apples, the RX-V665 would only output around 70wpc compared to the 95wpc rating of its predecessor. Of course with nearly an 8lb weight reduction and considering both receivers use linear A/B amplification, this also likely means the RX-V665 doesnt have the power reserves to drive multiple channels with as much poise and finesse as the RX-V663.

For the above example, the consumer must decide whether or not the upgraded features of the new receiver are worth the sacrifice in amplifier quality. I suppose it depends if the end user leans more towards emphasis of video features than audio. If they desire both and one day have intentions of adding external amplification, than doesnt this become a moot point?

Not always. From my testing of A/V receivers from various manufacturers, most of them simply slap preamp outputs on the back of their receivers for a marketing feature. It is a very inexpensive way to impress the unsophisticated user into being awed. They usually dont put decent op-amps that have enough output to drive external power amplification to its full potential without the internal preamp of the receiver first clipping and going into gross distortion. Remember these receivers are designed as a closed loop system to work optimally with their own internal components. If the manufacturer is cutting costs in the power supply of their product to offer you more features, its a safe bet they arent giving you a higher quality preamplification section to power an external amplifier.

Conclusion

Having done this job for some time now, Ive noticed this trend with many of the major brands over the years. Companies go through up and down cycles and as a result lose market share. As long as technology keeps evolving, manufacturers will do their best to cram in features of next generation products that were only previously found in their flagship models. While IC integration will trickle down technology, reducing production costs making it easier to achieve this, there will usually be other compromises in the lower end models to realize the feature count.

Finding that balance of basic performance compromises vs. relevant features is the equation that receiver manufacturers must figure out when launching their new platforms. It seems Yamaha has upset this delicate balance with their latest RX-Vxx5 series of receivers. We will be paying careful attention to this trend for all manufacturers during our product evaluations to recommend whether or not these new dream machines have the audio chops of their predecessors or if theyve got the tools to adequately drive external amplification for those looking for more power in their next home theater experience. Dont just run out and buy the latest model because its newer.

Stop and think if the model you currently have meets the performance vs feature balance that is right for your needs and how the newer so called improved model fits into that equation. All the features in the world cant replace clean undistorted dynamics which we believe makes up most of the WOW and magic in the newer HD audio formats."

Gene DellaSala Biography

The above content belongs to two of the Gene's articles as below:

Product Managing Receiver Platforms & Power Ratings

Trading Amplifier Quality for Features A New Trend with A/V Receivers?

 

[spirovious]

Here is the link abt 667-
RX-V667 - AV Receivers/Amplifiers - Yamaha - UK and Ireland

Now 667 is around 10.5kg,THD-0.06%
Now I have one question.When 400w is in use,how much power will preamp & video section need?
If I assume 50w,so I should get ideally 350/5ch = 70wpc. (5.1 setup)
If we consider heat,it should pump atleast 60w around.

Yamaha certainly produces less heat than my Onkyo and also has Damping factor upto 100-120 unlike 60 in Onkyo.

 

[rishiguru]

Fourthly it is very clear that you are slowly trying to bring in your God Made Amplifier unfittingly into this thread which is considered to be hijacking. Please limit your halleluiah to your own thread and spare the owners of Yamaha AVR.

Finally, showing this difference in power between two models of a brand, as the main reason why an old amplifier which does not even process discrete multi channel audio is better than the new AVRs for true home theatre experience, is simply RIDICULOUS. Forget HD audio, what's a home theatre which does not have 5+1 discrete audio channels.

Anyway let the discussion please be continued in your DSP-A2070 thread and whoever wishes to hear your "old" stories will meet you there.

Santy, I do not see any relevancy to what you said above to this thread. I request you to stay put with the topic of this thread.

I agree with you, there is a power loss in terms of heat due to inefficiency but I don't think class AB are that bad.. they must be around 75% efficient. I do not want to get into more details without sufficient knowledge. It needs more understanding especially when the 400W supply is AC and the amplifier extracts DC power!

So now you came to know that power amps are not 100% efficient & why heat is produced inside amps. GOOD.

By the way how do you came to the conclusion that Class-AB amps have an average efficiency of 75%? I mean I want to know about this GOD make Class-AB amplifier. I have very little knowledge regarding amps you know, so the natural tendency to learn.

 

[Santy]

Re: Why no HD DTS sign in panel

My 667 shows DTS on panel when a DTS disc is played.Then why when HD dts disc is played it shows STRAIGHT?Can anybody clarify?

You have to choose what information is to be displayed in the panel.
Three options are there in 471, not sure about 667
1. Input source
2. DSP program
3. Audio decoder.

If it shows "Straight" it means DSP is inactive.
DSP does not apply for HD audio. So it shows straight by default.
You must change the display to show Audio Decoder.
Check it and let me know.

 

[musicmypassion]

Fourthly it is very clear that you are slowly trying to bring in your God Made Amplifier unfittingly into this thread which is considered to be hijacking. Please limit your halleluiah to your own thread and spare the owners of Yamaha AVR.

I am missing 'Like' button in our forum?

 

[spirovious]

Re: Why no HD DTS sign in panel

You have to choose what information is to be displayed in the panel.
Three options are there in 471, not sure about 667
1. Input source
2. DSP program
3. Audio decoder.

Same in 667.DSP can be used with HD-audio,but it will downgrade audio quality.
I checked DSP setting & audio decoder used for them is either DD-prologic movies OR DTS-neo cinema.

 

[rishiguru]

Here is the link abt 667-
RX-V667 - AV Receivers/Amplifiers - Yamaha - UK and Ireland

Now 667 is around 10.5kg,THD-0.06%
Now I have one question.When 400w is in use,how much power will preamp & video section need?
If I assume 50w,so I should get ideally 350/5ch = 70wpc. (5.1 setup)
If we consider heat,it should pump atleast 60w around.

Yamaha certainly produces less heat than my Onkyo and also has Damping factor upto 100-120 unlike 60 in Onkyo.

I love to provide all your answers and it seems I do have to write another big one to clear the picture of this AVR.

But currently very very busy in work. Will try to write some stuff in weekends.

My buddy Santy have a bucketful of questions, and he is determined to prove me wrong, I can understand that part too, he is where I was a year before in the learning curve. But he will learn fast.

Same to you.

Look with 10.5kgs there is no way you can achieve 400 watts as power output.

Naked truth.

Secondly the 667 have two power supply units. One analog and the other digital. The total power consumption of both is 400 watts (I do not know in which basis & how they calculate this number & I am highly skeptical about them).

Yamaha RVX-667 interiors:

The EI transformer + power caps is the analog power supply dedicated for power amp. The switching power supply provides power to the pre amp, and all the circuit boards related to video processing.

The switching power supply seems to be big (left rear corner). I assume nearly 75 watts.

Also look at the size of the circuit boards dedicated for video processing, they are big. Video processing needs a lot of power.

Now looking at the transformer I highly doubt it is even a 300VA aka 300 watts transformer. Maybe even less.

Transformer weight & VA output goes hand in hand.

Norge 1000 interiors:


Now take this analogy. Our half baked Norge 1000 stereo amp with a much thinner profile casing, one 300 VA toroidal transformer, four tiny circuit boards with zero processing weighs 8.8 kgs. This amp can provide 160 watts of continuous power output.

Link : Anatomy of Norge 1000 Gold Stereo Integrated Amplifier

Yamaha 667 weight 10.5 kg. Difference = 10.5 - 8.8 = 1.7kg

Now the 667 with a much robust & bigger & taller casing(more weight), also with such huge video processing boards (more weight than tiny Norge 1000) plus a switching power supply unit (extra weight)+ front display + ............................... leaves how much weight for the transformer dedicated for power output?

The truth is after looking at the 667 transfo and its height, I think it weighs even less than Norge tranfo which equates to even less VA. Also Norge's toroidal tranfo is much superior than 667 EI core tranfo, toroidal tranfo weigh significantly less than EI ones but can provide the same VA output, due to their superiority in design.

I personally think this is a 250 VA transformer, and looking at the one bank of heat sink, it can dissipate 125 watts max.

Now considering the Class-AB amps have 50~55% average efficiency, we can say it will pump out 140 watts max of continuous power @ 20Hz-20kHz.

Heat dissipation : 250 - 140 = 110 watts

So we end up with 140/7 = 20 watts per channel of continuous power with all channels driven.

These are my thoughts, and you are free to think this a 1000 watt (GOD knows what kamazaki power rating) amp. Anything that makes you happy. Ultimately it is the sound that matters.

Also this trend of dwindling tiny power supplies for power output in favor of more and more cramped features is a trend that are followed by all AVR manufactures, not only Yamaha. It is race among manufactures of how many Dolby f@c&ing north east's & dts HD audio f@c&ing north west's they can cramp in a certain price bracket which will give them a decisive marketing advantage over its competitors.

The thing is a lot of people know the names of these features (few know what they actually do) & thus want them even though they will hardly use them, while one out of every 10,000 people knows what a power supply unit of an amp does. So what people forget is all the features in the world cant replace clean undistorted dynamics of a good power amp section which I believe makes up most of the magic.

So new marketing mantra for AVR manufactures : Give a shit to power supply & welcome more features. After all its features that sell.

 

[spirovious]

Yes,I had checked these pics before I purchased it.
http://www.hifivision.com/surround-amplifiers-receivers/12809-yamaha-rx-v667-7.html

Well Onkyo 609 claims around 610w powersupply & still weights 11.3.
On paper Onkyo looks powerful,but weight wise its not.Rotel AVR weighs around 25-30K.

What about Damping factor which Yamaha has almost double than Onkyo?

 

[prankey]

I have been patiently tracking this discussion of "continuous power" for the past few days and had hoped that someone would be able to enlighten Rishi "Guruji", however it seems the discussion is being dragged without a direction, so pitching in.

Guruji - Thanks for the great pics of the interiors of Norge and 667. However, this entire discussion of continuous power is useless as neither Yamaha or any other member here claims that it will give more than your "claimed" parameter which is ENTIRELY USELESS in Audio Engineering arena. Especially SOPHISTICATED AUDIO ENGINEERING as is done on all AVRs!

You have COMPLETELY OMITTED the FACT that HUGE CAPACITORS are used to hold momentary charge needed to suffice the power supply which CAN provide more than 1000w (hypothetically as I don't know the exact figures of this AVR) of instantaneous power when needed. So most of the times, even when the unit draws in excess of 1000 watts of power (typical during extreme volume, low/high dynamic range music/noise eg from a movie action sequence). Now as many have pointed out here, chances are, you will have hearing problems if you listen to the AVR connected to a decent low impedance speakers.

Audio has NO USE of "continuous" power. What matters is the RMS power which relates well to how we PERCEIVE audio! And that 1000Watts of peak RMS power may still consume around 300Watts or even less of continuous power like you have been talking about. But that doesn't change the fact that these receivers are capable of FAITHFULLY producing those much RMS power with ultra low distortion figure of 0.06% even when all channels are driven (distortion will increase, sometimes significantly when all channels play loud sounds, but the power output will still be stable at a reasonable/typical listening situation).

I know that higher rated transformer may actually improve the AVR's performance in extreme condition significantly, but that is not a TYPICAL situation we encounter everyday and hence manufacturer decide to consider an average situation only to consider a power supply.

Now this situation change for a high end stereo amp or an expensive AVR which are built to be abused by high listening levels and typical application is high intensity music and hence your Norge amp has a relatively higher rated supply with more continuous power per channel than the AVR (typical for an AVR).

So, while I am no way trying to contradict or pin you down, you seems to be very adamant with your half cooked understanding of "electrical engineering" rather than willingness to understand the underlying thought process the design engineers had while considering a component. I hope you do find this enlightening and you would be appreciative of my advocacy here. Lets stop judging an equipment by their weights, I have never done that and will never do it while still appreciating high performance/heavy duty devices irrespective of their actual weights.

 

[rishiguru]

I have been patiently tracking this discussion of "continuous power" for the past few days and had hoped that someone would be able to enlighten Rishi "Guruji", however it seems the discussion is being dragged without a direction, so pitching in.

Guruji - Thanks for the great pics of the interiors of Norge and 667. However, this entire discussion of continuous power is useless as neither Yamaha or any other member here claims that it will give more than your "claimed" parameter which is ENTIRELY USELESS in Audio Engineering arena. Especially SOPHISTICATED AUDIO ENGINEERING as is done on all AVRs!

You have COMPLETELY OMITTED the FACT that HUGE CAPACITORS are used to hold momentary charge needed to suffice the power supply which CAN provide more than 1000w (hypothetically as I don't know the exact figures of this AVR) of instantaneous power when needed. So most of the times, even when the unit draws in excess of 1000 watts of power (typical during extreme volume, low/high dynamic range music/noise eg from a movie action sequence). Now as many have pointed out here, chances are, you will have hearing problems if you listen to the AVR connected to a decent low impedance speakers.

Audio has NO USE of "continuous" power. What matters is the RMS power which relates well to how we PERCEIVE audio! And that 1000Watts of peak RMS power may still consume around 300Watts or even less of continuous power like you have been talking about. But that doesn't change the fact that these receivers are capable of FAITHFULLY producing those much RMS power with ultra low distortion figure of 0.06% even when all channels are driven (distortion will increase, sometimes significantly when all channels play loud sounds, but the power output will still be stable at a reasonable/typical listening situation).

I know that higher rated transformer may actually improve the AVR's performance in extreme condition significantly, but that is not a TYPICAL situation we encounter everyday and hence manufacturer decide to consider an average situation only to consider a power supply.

Now this situation change for a high end stereo amp or an expensive AVR which are built to be abused by high listening levels and typical application is high intensity music and hence your Norge amp has a relatively higher rated supply with more continuous power per channel than the AVR (typical for an AVR).

So, while I am no way trying to contradict or pin you down, you seems to be very adamant with your half cooked understanding of "electrical engineering" rather than willingness to understand the underlying thought process the design engineers had while considering a component. I hope you do find this enlightening and you would be appreciative of my advocacy here. Lets stop judging an equipment by their weights, I have never done that and will never do it while still appreciating high performance/heavy duty devices irrespective of their actual weights.

Thanks for the enlightenment.

I am in the learning curve too. I said that before.

And yes you are talking about dynamic power, the most important power factor for music listening.

But in my above post i talked about continuous power not dynamic.

Also I cannot see your so called "HUGE CAPACITORS" in this AVR, Yamaha must have nitro cooled and kept it away from sight since they are so huge.

They should be very close to the transformer, maybe under those tiny circuit boards extending from the transfo.

Next time I will try to use a magnifying glass to find your so called "HUGE CAPACITORS" under those tiny circuit boards.

May be capacitor nano technology? GOD knows.

And yes this "HUGE CAPACITORS" must have provided this amp with such high levels of dynamic headroom that Yamaha completely ommited to mention this parameter in the link spiro provided. :lol:

RX-V667 - AV Receivers/Amplifiers - Yamaha - UK and Ireland

By the way prankey, it is sometimes told that RMS power can be misleading?

Are you saying RMS & dynamic power are same? Kindly clarify.

I find there are huge debates in audio forums regarding this.

Can you show some light here?

Thanks prankey for providing us with your valuable comments.

 

[Santy]

This may appear to be OT but I promise it is not!hyeah:

I am autoguru and I wish to enlighten everyone on some important points which you must consider before you buy your first/ next car.

Take an example of New Honda City (NHC).

The total weight of the car is 1100kg.

I am sure with this weight, there is no way the car can produce 120bhp
This is the truth, believe it or not. I will try to explain it.

The NHC has two power units. One if from the batery for the lights, wipers, etc. The other one is for the wheels (much bigger one).

Let us have a look at the engine now:

This V Tech engine supplies power to the wheels. So essentially this is the part which drives the car forward. However it is not as good as straight cylinders used for eg. in the good old Ambassador. You know the latest tecnologies may not be always good.

Yes the new cars have better features to die for, but what about the power?
They have reduced the size of the engine so much to make the car more compact so the power is compromised. You cannot go faster in these cars as much as you used to go in 1985s for the same reason.

Why am I saying this? Look at the size of the enigne, its definetly smaller than the Amby's enigne and I highly doubt if the displacement can be 1490 cc as specified in brochure. It could not be more than 1000cc for its size. The weight could be around 250kg even if it is made of aluminium.

This is what my 1 year intensive research says.

So for a car of 1000cc, like the Wagon R, the power cannot be more than 80 bhp @ 4000 rpm. The company is claiming 120bhp which is grossly misleading and they are cheap advertising tactics.

Thats not all. There is still more to consider.

The internal combustion engine has an efficiency of 55%. The remaining is wasted as heat and gases. The muffler on the city is smaller than the Amby's muffler so that means it cannot spit the gases as much as it should.

The heat dissipation is done by the oil cooling unit, the sump of which is again small in size. The oil cooling unit has a pump, which usually draws about 5% of the engine's power. Honda engine usually runs cool, so I am sure the pump must be of high speed, drawing more power than nominal.

Then we have the transmission system. Quite a good amount of power is lost in the cluthes due to slipping.
This will take out atleast 15% of the power generated by the engine.

What more, the battery gets power from the engine through the alternator.
Last but not the least, the engine is connected to the flywheel which again takes away some power.
Finally braking power also comes from the engine. There are many more components like power steering which take some amount of power from the engine.

By all means, out of the 80bhp this engine produces, only 30 bhp is available for the wheels @ 4000rpm.
So 30 bhp / 5 wheels (including the spare one) = 6bhp continous power per wheel when all wheels are driven together.
Look at it, with this power, do you think the car can exceed 50kmph speed?

I am saying all these by assuming the weight of the car is 1100 kg which translates the weight of the engine to be around 250kg.
Comparitively the amby's engine is 400kg and much bigger.

So its evident that Amby is much better and faster than NHC.

Thanks for patiently reading my white paper on "How to calculate power of an IC engine based on its size and weight" :clapping:

 

[denom]

ROFL Santy, good one!!!

You also a 'Guru', I dd not know this 'fact'

heheheh, everyone is a 'Guru' these days, BUT at the end of the day,

'Half baked knowledge is far more dangerous than having No knowledge' :indifferent14::sad:

Lots of forums have found out that certain 'Guru' is spreading his brand of 'Half Baked Knowledge'

 

[musicmypassion]

Some so called 'Gurus' feel that our forum is very dry and no informative threads are running. So decided to step in and provide some 'Gyaan'

http://www.hifivision.com/amplifier...eo-receiver-good-buy-urgent-reply-please.html