AV_Phile;\r\n\r\nI feel I need to interject here for a moment as many of your statements are a bit misplaced. Yamaha never claimed the Z9 will deliver 170watts x 7 simultaneously. I know it may seem a bit misleading but welcome to the audio world where marketing rules! The truth is there really is no standard for multichannel power claims. Most manufacturers rate their amps on a per channel basis. They test at 1kHz because that does yield a slightly higher #. What you may also not realize is most reviewers make all channels power measurements while holding the line voltage constant (yet they don't usually state that). IMO a bogus test, far from real world. The majority of receivers and even power amps use unregulated power supplies (for a variety of reasons I won't expand upon here). Thus as the line voltage drops, so do the rails on the amps, especially when the Xformer saturates and the power supply caps run out of gas. \r\n\r\nThe all channels driven test is a bit of a misnomer. When do we actually listen to all channels driven simultaneously at full bandwidth continuously? If you do, you should get your hearing checked and your speakers to make sure nothing is blown. \r\n\r\nThe reality is the average power consumption of the receiver is much lower than you would expect, especially in todays home theater realm where all speakers are about 90dB SPL sensitive or higher, set to small, crossed over at 80Hz and have dedicated powered subwoofers (where the real power is needed!). \r\n\r\nWhat amazes me is how people squabble over a few watts for an unrealistic test and forget all of the technical merits, features and quality of the product. I agree playing the power game can get annoying, but Yamaha is far from being the first at doing this. Would you rather have a product with a substandard digital amp that claims even higher power (incidentally much higher distortion and noise) with much less processing power, features, and fidelity simply because it will deliver more power?\r\n\r\nI see now more than ever I need to slow down on writing cable articles and start writing articles on amplifier power :)\r\n\r\nThanks for responding, Gene. Let me respond to your points which are kinda surprising for me.\r\n\r\n(1) Firstly let me again point out that I am not cirticizing the Z9 receiver on it own. I am posting my distress at the technical write-up on the power specs. This applies not just for Yamaha but for most other new japanese models. Let me put on record that I am in fact astounded by the Z9 preamp's audio and video features as truly awesome and virtually future-proof. I am sure, the reciever will sound excellent under normal listening conditions. But in posting my critical comments on the specs, I just want to point out its overstated power features so as not to mislead users to expect something it cannot deliver, nor make any user wonder why it wouldn't sound as powerful as one similarly rated but conservatively measured. And I welcome most openly discussions to this end and to prove me wrong.\r\n\r\n(2) The Z9 is a multi channel equipment and as such, when its power spec tells you it has 170 wpc, it cannot but be interpreted as a 170 wpc amp SIMULTANEOUSLY for ALL channels. (Let's talk about its 7 identical channels and forget about its lesser powered 8th and 9th channel) The consumer expects THAT and when he talks about it with his fellow audiophiles, he uses that spec to say he has a 170 wpc multi-ch amp. How can such a spec be interpreted as "not to claim...simultaneously" for all channels??? Pls enlighten me. The spec is quite clear, let me quote:\r\n\r\nFront channels: 170w + 170w\r\nCenter Channel: 170w\r\nSurround Channels: 170w + 170w\r\nSurround Back Channel: 170w + 170w\r\n\r\nHere the Z9 did measure it as "Minimum RMS Ouput" for all audible frequencies 20hz - 20Khz at 0.015% THD, using FTC standards. FINE. But it says nothing about ALL CHANNELS DRIVEN, unlike some amps I know. I'll give them the benefit of the doubt. But look at the power consumption figures at the back: 1000 watts. It looks the part, the heft of the torroid suggests it's a 1KVA similar to that in some amps i've seen but with smaller ratings. With an extensive preamp circuit and another 8th and 9th channels beside, where will the amp get extra power to deliver 1,190 watts for its 7 channels when it eats only 1,000 watts? \r\nOK so I can concede Japanese amps are more efficient. Someone should nominate them for a Nobel prize in Physics for overcoming that immutable law that says you can't give more than what you took in. \r\n\r\nSo it's a nominal electric power rating. So is the "minimum RMS output." Still not congruent. More so if its a maximum electric power rating. I strongly suggest you compare this with a Rotel or an Aragon multi-channel amp electric power specification vis-a-vis their audio output power specification and see what I mean. \r\n\r\n(3) I am surprised to learn there is "no standard" for measuring multi-channel amps. True, they're a recent phenomenon (albeit, 10 years don't seem to make it new is it?) relative to the more than half-century evolution of the modern audio industry. But let's face it, when there is this EIAA, FTC, RIAA, etc etc standards specifying how to measure an amplifier's power output, it beggars the mind to accept the notion there is no standard. What have I been reading all along in amp specs?\r\n\r\nLet me say that the standards we have known regarding a conservative measurement of a stereo 2-ch amp's power should likewise be observed when rating a 100-channel amp. Using a 20hz-20khz test tone sweep or pink noise while driving ALL the channels to extract power from its transformer and into an 8-ohm load (resistive or real) at an audiophile grade distortion of no more than 0.05% or lower, we can expect a conservative audiophile power rating that is consistent across many brands and models and a prudent basis for comparison in terms of what can be expected as its power out. Just that.\r\n\r\nNow if a manufacturer devitates from that and measures his baby's power only at 1Khz driving only ONE channel and into a 4ohm load at a clipping distortion of 1% or some other, boy, you can expect a really high power figure there. \r\n\r\n(3) There is nothing unrealistic about having ALL CHANNELS DRIVEN as the basis for real-life expectation. Do you listen to your Stereo amp with only one channel? Do you listen to your multi-channel amp with only one channel?\r\n\r\nFurther, there is nothing unrealistic about expecting all audible frequencies to have the same power available to them than just at 1Khz. Do you listen to music at only 1Khz? While it is true that in real musical passages, not all frequencies are reproduced at any instant of time, my goodness, they're definitely a lot more than just 1Khz. To state your power at that point as if to imply or suggest that THAT is the power the consumer can expect when listening to music smacks of deception. In my school days in a true-or-false exam, if a statement is partly true, it is still false. Half-truths are still lies. They're more insiduous as they mislead the unwary. It's not even an inidcation of the power available to all the frequencies. 1Khz is the easiest with which to measure power rating. But the power available at 1khz can be so much more than the power available at 100hz. Much less when all the frequencies are being worked on by the amp at the same time. And much less if all the channels are driven at the same time.\r\n\r\n(4) "The reality is the average power consumption of the receiver is much lower than you would expect," True, so what is so wrong about telling it as it is. NAD, Harman-Kardon, Rotel, Acurus, Aragon, they tell it as such. They state their power output as CONTINUOUS with ALL CHANNELS DRIVEN into conservative 8-ohm loads and across all the 20hz-20khz audible spectra. \r\n\r\nNow if a manufacturer comes along and states his amp has 300wpc based on 1Khz with only ONE channel driven and into 4-ohm load, is the would-be owner correct in claiming he's got a more powerful amp than someone else's NAD conservatively rated at 120 wpc across all audible frequencies with All channels driven into 8 ohms? I can understand if he does, he's been mislead by an overstated specs. \r\n\r\n(5) Yamaha is certainly not the first to play the annoying "power game." I've seen Pioneers and Onkyos do the same. All, in the obvious effort to get more customers who, rightly or wrongly, believe that the higher the power the better. What is more galling is the first part of the Z9 power specs that read and I quote:\r\n\r\nDIN standard output power (4 ohms, 1khz, 0.7% THD)\r\nFront channels: 300w + 300w\r\nCenter Channel: 300w\r\nSurround Channels: 300w + 300w\r\nSurround Back Channel: 300w + 300w\r\n\r\nWhat is Yamaha thinking about? Is this a 300 watt multichannel amplifer or a 170 watt multi-channel amplifer? This is a totally USELESS and utterly misleading specification. Look at the back panel again and read the very revealing SPEAKER IMPEDANCE Caution: MINUMUM 6-ohms\/8-ohms. Does Yamaha expect the user to use 4-ohm speakers and expect it will last an afternoon delivering 300 watts per channel?\r\n\r\nWith such DIN conditions as I've stated above, you can really extract the most numbers. But what for?\r\n\r\nIf the objective is to capture more customers to buy their products, it would seem to me that these overstated specs are no different from the P.M.P.O. specs of most HITBs. Let me close by saying, i probabaly won't be the last word on this. But if this forum is interested in TRUTH the way I staunchly believe it does with cables and other myths, then talking about overstated specs would go a long way to unmasking the truth behind many japanese brands that so enthusiastically overstate their power specs.