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AV Receiver and Amplifier Power Ratings and Trends - Page 3

By Patrick Hart

The New 100 Watt Solutions

The numbers game comes into play with the mid-fi receiver manufacturers who hold larger receiver market shares via higher sales quantities of each model in their lines. Bear in mind that we've now gone through over 40 years of receiver design configurations. And from stereo receivers to 5 and 7 channel receivers and yet the price points throughout manufacturer's bread-and-butter models have remained almost constant. This is miraculous and a tribute to the designers and engineers and the companies who have striven to give their customers the best bang for the buck.

Barring testing major quantities of each model in each manufacturer's receiver line-up, I long ago (as Yamaha's Product Manager) learned to put a couple of specifications together to figure out how many "platforms" a particular receiver line from a major Japanese manufacturer might be using. I'll use Yamaha as an example once again because their receiver line-up seems to indicate the same two-platform line is carried on today as back in the eighties but with the added wrinkle that the lowest priced receiver is most probably built outside of Japan for cost reasons.

Look for differing chassis sizes . In the case of Yamaha there are three different chassis sizes.

In the chart below are the first two. Note that the RX-V450 has a slightly different chassis size than the other three more expensive models. This would indicate to me that this model is probably made under contract in China and that that manufacturer may have had a chassis already on hand or that that particular size may have allowed the contract manufacturer to build Yamaha's receiver for a bit lower labor cost. Whatever the reason, because a particular unit is built by another company does not mean it is any way of less quality than the rest of the Yamaha receivers. Rest assured that Yamaha probably has a full-time, well trained factory crew watching this and other contract factories on an almost daily basis to maintain the quality level necessary to carry the Yamaha name. 

MODELS

RX-V750

RX-V650

RX-V550

RX-V450

MSRP

$649.95

$549.95

$449.95

$299.95

AMPLIFIER SECTION

 


 


 


 


POWER RATING 1kHz @ 8 OHMS

7 X 115 WATTS

7 X 110 WATTS

6 X 105 WATTS

6 X 100 WATTS

POWER RATING -

20Hz - 20kHz @ 8 OHMS

7 X 100 WATTS

7 X 95 WATTS

6 X 90 WATTS

6 X 85 WATTS

THD (%) @ 8 OHMS

0.06%

0.06%

0.06%

0.06%

LINEAR DAMPING FACTOR

(20-20kHz)

140 OR MORE

140 OR MORE

100 OR MORE

100 OR MORE

Height
 6-3/4"  6-3/4"  6-3/4"  6-5/16"
Depth
 16-9/16"  16-9/16"  16-9/16"  16-3/8"
 Weight (lbs)
 27.8lbs  27.8lbs  24.2 lbs
 24.2 lbs
         

Okay, the other differences? Well the 450 and 550 are 6 channel receivers instead of 7 channel. So there's an easily discernible difference. And if you look at all the power figures @ 1kHz, 8 ohms you'll see that every receiver makes the magical 100 watt figure! Yes! That was the goal, most probably requested by the American sales and marketing team.

What is admirable on Yamaha's part though is that they still give full 20Hz to 20kHz bandwidth ratings at 8 ohms and a specific (maximum) THD figure for all models. These are the true wattage figures of which each individual power supply/amp section is capable before the "knee" of that power curve starts heading up.

Going back again; the 550 has 5 more watts than the 450 so what's the deal? Well, the units probably are made in different factories so the parts may be slightly different though rated identically. Similarly, the power supply is probably spec'ed identically but the 550's amp section may have the voltage rails bumped up just a tad to get that extra five watts. And that's the secret. Not much of a secret, huh?

Another item to look at is the weight of the 550 and 450. No difference. You're probably looking at identical power supplies and identical power amps, just different actual parts from different suppliers in different countries. And once again possibly, just possibly the 550's voltage rails are a volt or two higher than the 450 to claim the extra 5 watts.

Going up in the line to the RX-V750 and RX-V650 you've got an even more similar story. With identical weights you can be pretty certain that you've got identical power supplies with just the voltage rails bumped to make a couple more watts of power. Now onto the last way that 100 watts is still legitimately quoted…

That last and final way a couple of extra watts can be claimed for a receiver which has an identical power supply and power amp section is to simply quote power based on the higher distortion level of the curve after the knee as it heads up quickly toward the 1% level. By reading power figures off the curve after it's passed its lower distortion turning point or knee it's always possible to legitimately squeeze a couple extra watts out of a specification to keep the sales and marketing people happy. Just bear in mind that if you want to compare real watts vs. distortion you're always getting more accurate, real world figures on the horizontal section of the curve.

Remember too that it's extremely difficult to hear the difference between 100 watts and 110 watts. Like I said before, the 80-watt, 1996 Yamaha DSP-A3090 was one of the best sounding units Yamaha had built in years. And I believe part of the reason is that the engineers weren't forced to hit what was an unrealistic 100 watt figure given the great sounding, easy clipping, 80-watt topology they had at the time. The only other true avenue of freedom most receiver engineers have nowadays can be found in their top-of-the-line $4000+ receiver offerings. These modern day statement pieces are the closest the engineers have ever come to starting out with the proverbial "clean sheet of paper".

 

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Recent Forum Posts:

Deep Ear posts on July 17, 2015 15:11
Over the years, AV receiver manufacturers found ways to rate power less conservatively to give the illusion of more.

We all know this, we see it all the time.

But how did this trend start?


Gene-

What I recall happened when I became Yamaha's Product Manager in 1983 (from Kenwood Car Stereo) was as follows:

The Japanese audio manufacturers had all just decided to standardize component widths to 430-435 mm while mini component width which was common in products in Japan and I think the European market at the time was standardized at 350 mm. With this move the gargantuan high power receivers like the popular Sansui 5000 which dominated military exchanges all of the world ceased to be produced. So all manufactures were now tasked with getting (true RMS) higher power out of this much narrower, standard receiver width.

Second, Yamaha was really concerned with meeting UL specs because they and all their competitors were trying to come out with and market what they wanted the American audio consumer market to believe were proprietary amplifier typologies that “sounded better” than their competitors. For instance, Yamaha came out with a pyramid shaped amplifier with “X-power”. But unfortunately X-power was based on Bob Carver's small 200 Watt per channel 6“ x 6” x 6" cube topology. So I recall the bottom line with X-power was Yamaha's US-based certification engineer (named Lucky, no joke) told me at one time he had blown up 25 pre-production prototype amps Yamaha, Hamamatsu, Japan had sent him, none would pass UL.

Next, Yamaha Japan started asking me about the old IHF, Institute of High Fidelity power specs that Julian Hirsch (deceased) of Stereo Review followed which is essentially the same 20Hz - 20kHz, 8 ohm @ 0.XX% spec (at that time in the late 60's and early seventies still called cycles per second) that you are trying to get back to now. Yamaha's engineers told me they were having a really hard time meeting the full 20 Hz to 20 kHz bandwidth power spec at 8 ohms, how about if they used 6 ohms, would that be okay for our U.S.-only receivers? In the same breath they promised they would keep the 8 ohm 20 Hz to 20 kHz full bandwidth spec for Yamaha's integrateds and separates which were sold world wide.

It has been decades since Yamaha receivers first wowed specialist audio dealers (six hundred selling Yamaha at the time) and baby boomer audiophiles like me when introduced in the early seventies. At that time (wide and deep) Yamaha receivers stood alone against lesser manufacturers products which claimed 500 watts!, 1000 watts!. The power amplifier ratings game cycle as you have so astutely observed has sadly come all the way back to where we were then.

The one good piece of news I can share Gene is that when I began designing speakers for Marantz in Sun Valley, CA in 1971 Dawson Hadley (deceased) Marantz's chief engineer of American-built integrated's and separates started me off wiring the internals of my prototype speaker designs with twisted 14-gauge wire, a trick he had learned from JBL's Bart Locanthi (deceased). Physics don't change, but sadly a new generation of snake oil sales and marketing slubs seem to be ever-present. Sigh…
vinod.r posts on July 16, 2015 00:55
Hi Guys,

JEITA - Japanese Electronics Industries Trade Association.

It is another way of rating which is followed in products in Japan. Please correct me if I am wrong.

Vinod
highfigh posts on July 12, 2015 15:06
avengineer, post: 978307, member: 62593
HP 334A introduced in 1968 would read .1% full scale, down to .01% residual. The Tektronix AA501 would go to .001% with the SG504 oscillator as the source. The Tektronix 5L4N spectrum analyzer (early 1970s) had enough dynamic range to read THD (and separate it from N) well below 80dB. All pre-dated AP, and if I recall correctly, the founders of Audio Precision worked at Tek on the AA501 and related devices first, then left Tek to start AP.

BPI had some distortion analyzers, too. IIRC, we had the 3000 at the store where I worked.
gene posts on July 12, 2015 14:29
Splicer, post: 1089571, member: 63410
Gene, I just wanted to say THANKYOU for pretty much vindicating me on AVS. For years I have been ‘complaining’ that the marketing used on these lower (and sadly, upper as well) end subs always stating ‘1000 watts!’ (as an example) and always been chastised for doing so. But as you said in the video, look at the fine print to see the REAL numbers. The inflated, unusable and unrealistic numbers provided anymore are no more than marketing snake oil. Sort of like directional cables but I digress.

Just wanted to say thanks, I enjoy all of the Audioholic videos and the friendly bantar that accompanies them.
I appreciate your compliments. We are here to cut through the nonsense in marketing which sometimes makes us unpopular with the manufacturers and the fanboys too. At the end of the day, we share a common goal, a better audio experience without all the fluff. Hope you can participate more on this forum too.
Splicer posts on July 12, 2015 10:56
Gene, I just wanted to say THANKYOU for pretty much vindicating me on AVS. For years I have been ‘complaining’ that the marketing used on these lower (and sadly, upper as well) end subs always stating ‘1000 watts!’ (as an example) and always been chastised for doing so. But as you said in the video, look at the fine print to see the REAL numbers. The inflated, unusable and unrealistic numbers provided anymore are no more than marketing snake oil. Sort of like directional cables but I digress.

Just wanted to say thanks, I enjoy all of the Audioholic videos and the friendly bantar that accompanies them.
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