Product Managing Receiver Platforms & Power Ratings - page 3

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.

Okay, the other differences? Well the 450 and 550 are 6 channel receivers instead of 7 channel. So there's an easily discernable 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".