4 Amps To Compare

[zumbo]

My 200W PC Adcom's red lights have never come on even when occasionally I have had the volume up passed 0, driving 87 dB sensitivity floor standing speakers.

On mine.
Amber for clipping. Red for protection mode.

Driving 86dB 4ohm floorstanders. They ambers flicker on the mains from time-to-time.

 

[PENG]

On mine.
Amber for clipping. Red for protection mode.

Driving 86dB 4ohm floorstanders. They ambers flicker on the mains from time-to-time.

Mine is the older model GFA-555. It only has the distortion alert LED's that I believe are supposed to light up when distortion reaches 1% or higher. Anyway, your 86 dB 4 ohm floor standers certainly won't be happy with anything less than separate power amps.

 

[zumbo]

Mine is the older model GFA-555. It only has the distortion alert LED's that I believe are supposed to light up when distortion reaches 1% or higher. Anyway, your 86 dB 4 ohm floor standers certainly won't be happy with anything less than separate power amps.

Believe it or not, they ran off my Yamaha rx-v1400 for an entire year without one problem. The receiver never shut-down. The fans were kicking alot though.

 

[mtrycrafts]

but then you may have trouble dealing with the speaker's own high distortion level when they are pushed to their limit even if you use power amps.

Few tend to think about this

 

[mtrycrafts]

Clipping per se will not hurt the speakers, what will hurt them is power. A 100w amp fully clipped will deliver 200 watts of RMS power to the speakers this is what will blow them. The output basicly turns into a square wave, hence increasing the rms power. The extra headroom is nice but you will hear the speakers bottoming out. I would go with 110-140 W/ch. This should do you fine. In reality any of todays decent receivers will do a fine job driving your speakers. If you want seperates because of the look (which I personally love) I'd go with a couple Adcom or similar amps. The bottom line is: All of the amps you have listed will do the job, but dont expect them to sound different from each other.

Am I reading this correctly?

 

[MacManNM]

Am I reading this correctly?

Yeah smarrtycrafts , your reading it right. Now, when it comes to receivers, and pre/pros, there is a huge difference in some. Very audible, but this is mainly due tho things each mfgr has put into the units (room compensation, parametric eq, better electronics, etc).

 

[Josuah]

I didn't understand MacManNM's post at first, but I think I get it now. When you drive a 100W amplifier to clipping, it is going to maintain +100W and -100W for an extended period of time, due to the square wave nature. At the extreme, you will end up with a signal that is only +100W and -100W. Thus, the conclusion of 200W RMS.

At least I think that's what the paragraph was saying. I disagree with the +100W and -100W ending up counting as 200W RMS, as it's not exactly considered a differential as far as the speaker is concerned. But that will make the speaker blow up.

 

[tdeluce]

Earthquake also has the lights that warn about approaching clipping. I have seen them come on but didn't push the speakers further. It might have been interesting to try.
Roly

I listen at reference levels, sometimes a little above and sometimes a little
below and the clipping LEDs have never come on on my Cinenova Grande 3

 

[mtrycrafts]

I didn't understand MacManNM's post at first, but I think I get it now. When you drive a 100W amplifier to clipping, it is going to maintain +100W and -100W for an extended period of time, due to the square wave nature. At the extreme, you will end up with a signal that is only +100W and -100W. Thus, the conclusion of 200W RMS.

At least I think that's what the paragraph was saying. I disagree with the +100W and -100W ending up counting as 200W RMS, as it's not exactly considered a differential as far as the speaker is concerned. But that will make the speaker blow up.

No, that is not what is happening. The RMS value of a square wave is the peak power of the output. A sin wave RMS is .707 of the peak.

 

[Josuah]

Thus, my disagreement with it equalling 200W. I was trying to be tactful.

 

[zumbo]

I listen at reference levels, sometimes a little above and sometimes a little
below and the clipping LEDs have never come on on my Cinenova Grande 3

No! With 600wpc on tap, I bet they never come on. I'd better give Mathew a call.

 

[PENG]

No, that is not what is happening. The RMS value of a square wave is the peak power of the output. A sin wave RMS is .707 of the peak.

You got that right.

 

[mtrycrafts]

Thus, my disagreement with it equalling 200W. I was trying to be tactful.

OK, I just figured it out. When you figure out the RMS rail voltage, at 100 watts, I used another amps test data(BehringerA500) as the rail voltage was given, then figure the peak voltage of that RMS voltage used to give RMS power, it is 1.414 more than RMS voltage. That higher voltage also increases the amps. Using that higher amp value with the higher peak voltage, the power doubles indeed. So, we have the right answer, 2X power of RMS power.