Interesting review in hometheater mag on the yamaha 2400 (1 Viewer)

[RickardL]

I took a look at the reviews at (UK) www.homecinemachoice.com:

YAMAHA RX-V540RDS AV Receiver Review August 2003

Manufacturer¡¯s rated output: 70W per channel (20Hz-20kHz,8 §Ù, 0.06%THD)
Measured power output @ 1kHz (2 channel): 90W (8 §Ù, 0.1%THD); 70W (4 §Ù, 0.1% THD)
Measured power output @ 1kHz (5-channel): 35W (8 §Ù, 0.1%THD); 30W (4 §Ù, 0.1% THD)
Fidelity firewall: 80W @ 0.05% THD (8 §Ù)
Distortion @ 50W: 0.01% (8 §Ù, 1kHz)

YAMAHA DSP-AZ2 AV Amplifier Review June 2003

Manufacturer¡¯s rated output (six main channels): 130W (20Hz-20kHz, 8 §Ù, 0.02%THD)
Measured power output @ 1kHz (2 channel): 145W (8 §Ù, 0.1% THD); 230W (4 §Ù, 0.5% THD)
Measured power output @ 1kHz (5 channel): 75W (8 §Ù, 0.3% THD); 120W (4 §Ù, 4.5% THD)
Fidelity firewall: 145W @ 0.02% THD (8 §Ù)
Distortion @ 50W: 0.0015% (8 §Ù, 1kHz)

note: §Ù should be the ohm-sign...

 

[Mark All]

While I would like more detailed/honest power ratings for receivers, I don't really see why one should be concerned about the test results alone for the Yamaha 2400 or most of its competitors. I guess the Yamaha 2400 can provide 120 watts or so with one channel driven, 103 watts with two channels driven full range, and 32 watts with all seven channels driven full range. The 120x7 rating is pure marketing hype and I'd hope readers of this forum would be well enough informed as enthusiasts in the hobby to know it for what it is. The Yamaha 2400 can indeed provide 120 watts per channel as long as only one channel is driven at a time--truthful but deceptive at the same time.

Why doesn't the actual power output make much difference to me? Because all seven channels in a home theater receiver don't get full range signals all the time. Most of the time the main and center speakers carry most of the burden with surrounds requiring very little power. Also, when paired with a subwoofer many home theater receivers are only used to power speakers in small mode.

However, when used for multi-channel high resolution audio the low actual power ratings may present performance problems for mixes that rely heavily on all five channels being driven at the same time.

One thing that does bother me about the design of the Yamaha 2400 is that the company decided to use a power supply with a fan rather than providing heftier heat sinks. Still, the receiver is unlikely to have heat shut down problems in most home theater settings. If one is trying to drive power hungry speakers that would cause a mid-range receiver to shut down though one is better off in the first place of buying a separate amplifier for power instead of a receiver. I do believe that receivers present the best value for home theater when used as by themselves or as pre-pros.

 

[Lewis Besze]

Besides, doesn't distortion rise very very rapidly once the amplifier is clipping?

Yes,which why it is measured to that point of clipping.

 

[Dave^Wein]

Ummm.

Why is everybody ignoring the 0.1% part of the review.

I have not read the review, but from the original post, it is possible that the 2400 puts out 600 watts/channel into 7 channels at 0.12%THD.

Do you guys understand that?

I suspect that the review was using a 20hz-20khz distortion test, where a thd above 0.1 at any frequency on any channels would abort the test.

So chill.

Dave

 

[Rich Wenzel]

I know I have seen clipping as THD of 1%...a 1 minute search brought up this article on hometheaterhifi:

http://www.hometheaterhifi.com/volume_3_2/v3n2e.html
http://www.audiocontrolindustrial.co...trolIndust.pdf

from a SGTH review:
"With five channels driven, the AVR-5803's power output at clipping (1% THD+noise) into 8ohm measured 170 watts per channel at 1kHz and 141Wpc at 20Hz..."

also some high end manufacturers give their ratings at 1% THD because that is considered clipping, for example:

http://www.mccormackaudio.com/dna225.html
http://www.conradjohnson.com/It_just...-products.html

Rich

 

[Michael R Price]

Well, not every amplifier produces less than 0.1% THD under all conditions except clipping.

 

[Marty M]

One thing that does bother me about the design of the Yamaha 2400 is that the company decided to use a power supply with a fan rather than providing heftier heat sinks.

Are you sure about the fan instead of heat sinks. My dealer told me there were heat sinks. Maybe he was mistaken or I misunderstood his answer. I will look into this.

 

[Gordon Moore]

Where does the fan exhaust to? There's no fan on the back of the unit.

 

[BrentG]

If it is a fan it is darn quiet, because I have never heard one on mine before.