AMPS: High Power Vs High Current?

[mtrycrafts]

So you guys go by numbers, specs, rather than your own ears? That makes no sense at all. We are talking about audio products and not baseball players ya know?

Sent from my Pixel using Tapatalk

Of course it makes lots of sense. We also listen. Numbers don't disappoint. Listening can. Or, rather the brain can disappoint in its translation of what goes to it.
To many not looking at the numbers makes zero sense.

 

[mtrycrafts]

... but they all get "dirty" when pushed beyond their limits.

So does a lot of things.

 

[PENG]

That 5x200W into $ Ohms is why my curiosity. And as you pointed out with your numbers, things just don't sound right. At 200 Watts, you are only talking about 7A per channel. So, yes, 5 of those would be 35A RMS
total. And, to me, 7A per ch is not high current but a good amp that is capable of full power with all channels driven.

It's subjective, and relative and that's why right from the start of this thread some us including you and I have already said this is more marketing hype, even BS (TLSG) than fact.

Remember those $6,600, $100/lbs!! 50WPC Denon integrated amp that doubles down to 100WPC? I would call it high current in relative sense but Denon's own flagship AVR would have much higher current capability in absolute sense right? Anyway I think we have our fun, and I hope Phil gets enough answers to choose from.

 

[PENG]

Well, even if the amp can dump 31.8A rms(45A peak) 1 ch into a 1 ohm load(31.8V), that would be 1011 Watt for that channel. Don't think so. So, it seems they may be talking total amps for 5 ch.

Their website definitely says each channel, but again that typically does not mean all channels simultaneously so there is nothing surprisingly if can dump 32A into 1 ohm for a split second. When they say "peak", that typically means literally peak value, and/or for very short duration. We are guessing, I would have email them but I won't waste my time because it's all academic, no practical value at this point for me.

 

[PENG]

Hey, how was the watermelon......LOL?????? I ended up eating a 2nd piece and finished the last one a bit earlier. Oh man was it ever delicious! Just am curious if yours was good as well......LOL!!!!!


Cheers,

Phil

I ate them up, too much water for late evening consumption but no regrets. I think they were from Costco.

 

[PENG]

I agree that most (almost all) amps provide clean power at their published limits, but they all get "dirty" when pushed beyond their limits.

Yep, some gets ugly, yet could be hot at the same time..

 

[speakerman39]

Yep, some gets ugly, yet could be hot at the same time..

Ummm you mean like hot chicks w/ugly personalities.............LOL?????? Met a few of them in my day. Heck, I even married one. Suffice it to say I just never realized how ugly her personality was until after we got married..........LOL!!!!


Cheers,

Phil

 

[lovinthehd]

So you guys go by numbers, specs, rather than your own ears? That makes no sense at all. We are talking about audio products and not baseball players ya know?

Sent from my Pixel using Tapatalk

I don't think good baseball managers choose players by specs alone either....maybe they even listen to them .

The audible influence of an ss amp is minimal IME, level matched and within it's capabilities/comfort zone and all that....

 

[Pogre]

So you guys go by numbers, specs, rather than your own ears? That makes no sense at all. We are talking about audio products and not baseball players ya know?

Sent from my Pixel using Tapatalk

I trust my ears. I also trust the opinions of seasoned audiophiles who have a lot of experience with different amplifiers, receivers, etc, which is virtually every regular member here. I've never been led wrong in over a year here.

When the data correlates with DBT, yes. I rely on data to a point.

 

[mtrycrafts]

Their website definitely says each channel, but again that typically does not mean all channels simultaneously so there is nothing surprisingly if can dump 32A into 1 ohm for a split second. When they say "peak", that typically means literally peak value, and/or for very short duration. We are guessing, I would have email them but I won't waste my time because it's all academic, no practical value at this point for me.

I hate to belabor this but an amp rated at 140/200 watts 8/4 Ohms be able to dump peak power of 1011 Watts(1 ohm-31A) in one channel is a bit hard to swallow especially with a dynamic headroom specked at 1.5 dB no matter how one slices it.
End.

 

[AcuDefTechGuy]

So you guys go by numbers, specs, rather than your own ears? That makes no sense at all. We are talking about audio products and not baseball players ya know?

Sent from my Pixel using Tapatalk

I think you are referring to people buying amps based on specs like SNR, Crosstalk, THD, FR, Currents/Volts/Watts ?

If so, I think most of us just get the amplifiers that have the power and quality we want, instead of worrying about the numbers.

 

[panteragstk]

I go by specs first, ears second. I'll buy based on specs then make sure my ears like. Now, if I heard something BEFORE I read the specs then I'd rely less on specs, but would still want to see them because I am a numbers nerd. Kind of like power to weight ratio with cars. If I see that a car as 500hp but weighs 5000lb I'll be a bit less impressed than the same power out of a sub 3000lb car.

Specs are very important.

 

[PENG]

I hate to belabor this but an amp rated at 140/200 watts 8/4 Ohms be able to dump peak power of 1011 Watts(1 ohm-31A) in one channel is a bit hard to swallow especially with a dynamic headroom specked at 1.5 dB no matter how one slices it.
End.

Again, no one said it would do it continuously, I would say not even for 1 second. For a split second though, say, 20 ms as Yamaha appeared to base their dynamic output on, it is quite conceivable for an amp rated 200WX5 (cont.) to send 31A into a 1 ohm load without tripping any breakers,

http://faq.yamaha.com/us/en/article/audio-visual/av-receivers-amps/997/2439/what-s_the_difference_between_continuous_rms_and_dynamic_power_

Avtech tested the Parasound A21's dynamic output into 2 ohms (not 1 ohm), it passed with 1105.9W at <1% distortions and almost 1200W at <2%. Note that Parasound's website did not specify distortions level either, nor the duration of output at 45A peak.

http://www.milleraudioresearch.com/download2011/reports/nov11/parasound_halo_a21.html

The Bryston 4B SST (300WPC) was tested to 1 ohm, 2003.3W at 0.7% distortions.

http://www.milleraudioresearch.com/avtech/

If you browse through that avtech website, you will see that not every amp or avr had such high dynamic output on their bench, but a few of them did, even a few AVRs ( a couple of Yamaha's) can do 400-500W, in fact almost 600W.

I said it right from the beginning, and repeated at least once, that this thing is more marketing hype than practical facts because just by saying 45A without being stating the test conditions such as duration, distortion, waveform, rms vs peak etc. That does not take away the possibility that the unstated conditions could be something like, 10 ms, at 2%, or even 10% THD, using regulated power supply etc.etc., we can only guess..

I actually thought we were in agreement. You seemed to bull dog on the 1000W into 1 ohm thing, perhaps not considering the qualifying key factors such as duration, distortions, among others.

 

[mtrycrafts]

Again, no one said it would do it continuously, I would say not even for 1 second. For a split second though, say, 20 ms as Yamaha appeared to base their dynamic output on, it is quite conceivable for an amp rated 200WX5 (cont.) to send 31A into a 1 ohm load without tripping any breakers,

http://faq.yamaha.com/us/en/article/audio-visual/av-receivers-amps/997/2439/what-s_the_difference_between_continuous_rms_and_dynamic_power_

Avtech tested the Parasound A21's dynamic output into 2 ohms (not 1 ohm), it passed with 1105.9W at <1% distortions and almost 1200W at <2%. Note that Parasound's website did not specify distortions level either, nor the duration of output at 45A peak.

http://www.milleraudioresearch.com/download2011/reports/nov11/parasound_halo_a21.html

The Bryston 4B SST (300WPC) was tested to 1 ohm, 2003.3W at 0.7% distortions.

http://www.milleraudioresearch.com/avtech/

If you browse through that avtech website, you will see that not every amp or avr had such high dynamic output on their bench, but a few of them did, even a few AVRs ( a couple of Yamaha's) can do 400-500W, in fact almost 600W.

I said it right from the beginning, and repeated at least once, that this thing is more marketing hype than practical facts because just by saying 45A without being stating the test conditions such as duration, distortion, waveform, rms vs peak etc. That does not take away the possibility that the unstated conditions could be something like, 10 ms, at 2%, or even 10% THD, using regulated power supply etc.etc., we can only guess..

I actually thought we were in agreement. You seemed to bull dog on the 1000W into 1 ohm thing, perhaps not considering the qualifying key factors such as duration, distortions, among others.

Well, that one ohm is what seems to be the load to get that power. 2 Ohms would be 2 k Watts with that current. Will the output power transistor withstand such power even in ms peaks?
Yes, I could have used 45A peak to get even a much larger peak power, like 2k Watts; I was very generous.
Also, how does that published 1.5 dB dynamic overhead comes into play?

 

[PENG]

Well, that one ohm is what seems to be the load to get that power. 2 Ohms would be 2 k Watts with that current. Will the output power transistor withstand such power even in ms peaks?
Yes, I could have used 45A peak to get even a much larger peak power, like 2k Watts; I was very generous.
Also, how does that published 1.5 dB dynamic overhead comes into play?

Yep, that's one reason why I consider such spec not very helpful (don't want to say useless). As for the transistors, if you use enough of them they can take a lot of current but of course time (heat) is a huge factor, and remain in their safe linear operating range too.

Regarding the dynamic headroom (not sure about dynamic overhead either), that's another buzz word that frustrate people, me anyway, as there seem to be no consensus in the term's definitions. It would seem that some amp manufacturers would use that term to specify a little more output than their rated "continuous" output for a short duration at the same or slightly higher distortion, yet typically without telling you how short that duration is. Despite the very unclear definition, this term is still a tight more meaningful than the 45 amp peak, or instantaneous number, because the latter typically won't tell you anything about the test conditions. At least for the dynamic rating they normally make it clear that it is based on 8,4,2 ohm (such as Yamaha) and even % distortions etc. Theoretically, specs that claims 45, 60 or higher (seen it before) amperes could have been for 0.0000000001 second at 100% distortions into a dead short, though that would be totally ridiculous, but just for argument sake.. If you can find the definition of dynamic headroom for audio power amplifiers from some authoritative sources (e.g. FTC..), please share.

 

[ski2xblack]

Regarding the dynamic headroom (not sure about dynamic overhead either), that's another buzz word that frustrate people, me anyway... If you can find the definition of dynamic headroom for audio power amplifiers from some authoritative sources (e.g. FTC..), please share.

Dynamic power ratings via the IHF method and old school THX certification requirements for amplifiers, just off the top of my head. I can only think of two brands who tout IHF specs in their marketing/manuals, Yamaha and NAD, and I really don't know what THX has devolved into these days, or if any amp makers bother with the certification any more.

 

[panteragstk]

Dynamic power ratings via the IHF method and old school THX certification requirements for amplifiers, just off the top of my head. I can only think of two brands who tout IHF specs in their marketing/manuals, Yamaha and NAD, and I really don't know what THX has devolved into these days, or if any amp makers bother with the certification any more.

Onkyo still does. I think a lot of speakers and TVs still do as well. Not sure why though...

 

[PENG]

Dynamic power ratings via the IHF method and old school THX certification requirements for amplifiers, just off the top of my head. I can only think of two brands who tout IHF specs in their marketing/manuals, Yamaha and NAD, and I really don't know what THX has devolved into these days, or if any amp makers bother with the certification any more.

Exactly, Yamaha is quite (not totally but good enough I guess) forth coming about the test conditions, such as telling you the test signal frequency, the duration and distortion level.

 

[Verdinut]

QSC Audio define Dynamic Headroom as follows:
" Since the 1980's, the cost of high-voltage transistors has come
down, so the trend has been toward somewhat smaller transformers to reduce the weight of amplifi-
ers, even though the no-load voltage rebounds to a higher level.
A side effect of the voltage drop is that, because the filter capacitors charge up to higher voltage
during periods of low demand, the amplifier can deliver a momentary burst of power above its
normal rating. This feature, called dynamic headroom, can add 2dB or 3dB of peak undistorted
power, which is equivalent to having up to 100% more wattage."

 

[M Code]

Keep in mind...
When talking about dynamic headroom older legacy analog products simply had higher noise floors..
As the CD, PCM and other digital audio streams evolved the noise floor was pushed down significantly so up came the dynamic headroom..

Just my $0.02...