Need imput on an amp

[KEW]

For example, with all channels driven (7) an AVR may produce 100WPC x 7. But with only 2 channels driven, the same AVR may produce 200WPC x 2.

For example, the Denon 5308: 169WPC x 7 ch driven --> 339WPC x 2 ch driven, which is basically DOUBLED.

Where did you get those numbers on the Denon?
Audioholics tests put it at:

Denon AVR-5308CI Power output: < 0.1% THD + N

* 1CH, 8 ohms: 160watts
* 2CH, 8 ohm, 150wpc
* 1CH, 4 ohms: 240wpc
* 2CH, 4 ohm 220wpc

Unfortunately, I believe most AVR's rated at 100WPC are more likely to produce 100WPC into two channels and drop to 65-80WPC if asked to deliver to all 7 channels at once. The good news is if you ask this amp to play in stereo, it should have good headroom since the marginal 7 channel capacitance is usually ample for two channels.

 

[KEW]

It's to bad they don't make receivers so you could switch the power from the amps rear or suround speakers to the fronts so you could double the watts per chanell then100 watts per chanell would be come 200. I don't know if that is crazy or not you tell me? I"m not high tech although I've learned a lot on this forum; I think it would be pretty neat especially for two chanell music listening and power hungry speakers and no need for a seperate 2 chanell amp.

There are some separate 5 channel amps which will allow you to bridge two pairs of channels. I forget who made (makes?) them, but their specs were along the lines of 5ch x 120 or 2ch (bridged) x 200 + 1ch x 120.
I suspect the cost of incorporating the bridging circuit into an AVR is excessive and AVR companies usually sell (or have a sister company that sells) amps to people who want/need more.

 

[AcuDefTechGuy]

Where did you get those numbers on the Denon?

Home Theater Magazine.

 

[waxey]

Thanks for the reply didn't know power increased that much when switched to 2 chanell. I still mite go with an amp in time but its not a priarity a right now.

 

[AcuDefTechGuy]

There are some separate 5 channel amps which will allow you to bridge two pairs of channels.

Bridging the channels will increase distortion, which defeats one purpose of gettting separates in the first place.

 

[AcuDefTechGuy]

Where did you get those numbers on the Denon?

http://www.hometheatermag.com/receivers/808denr/index3.html

HT Labs Measures: Denon AVR-5308CI A/V Receiver
Five channels driven continuously into 8-ohm loads:
0.1 percent distortion at 146.1 watts
1 percent distortion at 184.6 watts

All channels driven continuously into 8-ohm loads:
0.1 percent distortion at 141.2 watts
1 percent distortion at 169.3 watts

This graph shows that the AVR-5308CI’s left channel, from CD input to speaker output with two channels driving 8-ohm loads, reaches 0.1 percent distortion at 207.0 watts and 1 percent distortion at 235.5 watts. Into 4 ohms, the amplifier reaches 0.1 percent distortion at 279.4 watts and 1 percent distortion at 339.2 watts.

Oops, I meant 235 Watts x 2ch, not 339 Watts.

So it's 169WPC --> 235WPC.

 

[KEW]

http://www.hometheatermag.com/receivers/808denr/index3.html

HT Labs Measures: Denon AVR-5308CI A/V Receiver
Five channels driven continuously into 8-ohm loads:
0.1 percent distortion at 146.1 watts
1 percent distortion at 184.6 watts

All channels driven continuously into 8-ohm loads:
0.1 percent distortion at 141.2 watts
1 percent distortion at 169.3 watts

This graph shows that the AVR-5308CI’s left channel, from CD input to speaker output with two channels driving 8-ohm loads, reaches 0.1 percent distortion at 207.0 watts and 1 percent distortion at 235.5 watts. Into 4 ohms, the amplifier reaches 0.1 percent distortion at 279.4 watts and 1 percent distortion at 339.2 watts.

Oops, I meant 235 Watts x 2ch, not 339 Watts.

So it's 169WPC --> 235WPC.

WOW! That is a pretty impressive AVR, but I guess at $5200 it has something to prove!

 

[PENG]

Where did you get those numbers on the Denon?
Audioholics tests put it at:


Unfortunately, I believe most AVR's rated at 100WPC are more likely to produce 100WPC into two channels and drop to 65-80WPC if asked to deliver to all 7 channels at once. The good news is if you ask this amp to play in stereo, it should have good headroom since the marginal 7 channel capacitance is usually ample for two channels.

HTM gave it 339WX2 into 4 ohms at 1% THD, dropped to 279WX2 at 0.1% THD. If Audioholics had lower numbers they might have tested it at lower THD.

I have to agree with you regarding using a 7 channel AVR for two channel application. This is what HTM said about a Sony, yes even a Sony receiver could yield some usable power for two channel listening.

"This graph shows that the STR-DA5400ES’s left channel, from CD input to speaker output with two channels driving 8-ohm loads, reaches 0.1 percent distortion at 157.5 watts and 1 percent distortion at 186.6 watts. Into 4 ohms, the amplifier reaches 0.1 percent distortion at 249.9 watts and 1percent distortion at 296.0 watts."

Here's the link:

http://hometheatermag.com/receivers/sony_str-da5400es_av_receiver/index3.html