Opinions Wanted - My Amp Quandary

Adam

Adam

Audioholic Jedi
Adam, let me try to rationalize this for you.
Thanks, Peng. Great explanation. I was thinking of power draw, not output, so the 543 W number is what I was after. Also, my main confusion came from me being in a hurry (or tired, or both) and having read "0dB" as being a minimum volume setting (i.e. no output) as opposed to what it really is. My mistake. :( The numbers make much more sense now that I've gotten my head back in the game.

Thanks, again.
 
P

PENG

Audioholic Slumlord
Thanks, Peng. Great explanation. I was thinking of power draw, not output, so the 543 W number is what I was after. Also, my main confusion came from me being in a hurry (or tired, or both) and having read "0dB" as being a minimum volume setting (i.e. no output) as opposed to what it really is. My mistake. :( The numbers make much more sense now that I've gotten my head back in the game.

Thanks, again.
You are welcome. By the way, I checked, Sony does provide both watts and VA in their power consumption spec. On the other hand, no one knows exactly what power consumption figures are based on. Some say it is based on 2 channels at rated output + a percentage of the rated output for the other channels but I am not sure if there is a standard for it. HK is one of the few manufacturers that specify their power consumption as "maximum power consumption" meaning (a reasonable assumption) with all channels driven. Because of that, one can figure out roughly the efficiencies of HK receivers.
 
G

Gov

Senior Audioholic
Adam, let me try to rationalize this for you. Firstly, people tend not to bother distinguishing VA and Watt for simplicity sake. In reality VA=voltageXCurrent, i.e. VoltsXAmps. In electrical engineering term we refer to this product, VoltsXAmps as VA, not watt. You can in fact find this term in some receiver or amp specifications if you look at the power consumption figures. VA equals watts only for purely resistive loads when the phase angle between the voltage and current vector (more correctly, phasor) is zero. That is they are in phase. For reactive loads, Watts=VoltsXAmpsXPower factor where Power factor is less than 1 unless the voltage and currents are in phase. The more reactive the load is, the larger the phase angle between volt and amp and the lower the resultant power factor. Secondly, you have to consider efficiency, I am not sure if the LPA-1 is a class AB amp. If it is, then its efficiency could be around 50% or lower. So let's say Gov's display indicates peak values of 8 amps, and assuming the waveform is sinusoidal (mostly likely not), the rms value will be 8/1.414=5.66A, further assume the power factor is 0.8, then Power draw from the 120V side=120X5.66X0.8=543 Watts. Finally if we assume the amp's efficiency is 50%, then Output power=Input powerXefficiency=272 watts. That is quite believable consider that he said he had the volume at 0 dB, especially if his listening position is far enough (say 10 ft or more) from the speakers.

:D I could not have said that at all!!
 
adk highlander

adk highlander

Sith Lord
Adam, I spoke with Lonnie today about the "hum" that my MPS-1 makes. He said the noise I am hearing is normal. I think I hear it more now that I put a back on my rack which pushed the sound out toward me. It is minimal and if I am watching an HD DVD the A2's fan is way louder so I never hear it when it counts.

On another note, Lonnie is a great guy. He took the time to really make sure that I felt comfortable with his answer and then he then told me about some of the new stuff that they are coming out with and the reasons for their delay with their new prepro's. It is great to speak with a rep that truly knows their product and cares how the customer feels.

One tidbit I will share is that the dual sub amp that they demo'd at the audioholics party will be changing from 800w to 1000w and have a two line lcd to view and make adjustments. Still for the same price.
 
Davemcc

Davemcc

Audioholic Spartan
One tidbit I will share is that the dual sub amp that they demo'd at the audioholics party will be changing from 800w to 1000w and have a two line lcd to view and make adjustments. Still for the same price.
This is an interesting development. It will be nice to have the lcd to be able to see and confirm the room correction settings.
 
GlocksRock

GlocksRock

Audioholic Spartan
That is a sweet addition, I don't know how much difference the extra 100 watts per sub will matter, but the LCD will be a welcome addition.
 
Davemcc

Davemcc

Audioholic Spartan
That is a sweet addition, I don't know how much difference the extra 100 watts per sub will matter, but the LCD will be a welcome addition.
I have a feeling that the extra watts will make a difference, simply because they are high excursion drivers in a sealed enclosure. My impression is that ported enclosures offer less less air resistance within the cabinet for the driver to overcome, so in a sealed box, the extra power will be useful in overcoming the pressurized air in the box, allowing more excursion and more control.

If it makes the production models more capable than the system I heard in Clearwater, it's going to be nearly impossible to beat.
 
A

arftech

Junior Audioholic
You nailed it! My mindset is...if I can order it and have it shipped on Monday from Emotiva, it should arrive on Friday (based on my past two shipments), which is my next weekday off from work.



Sometimes? Try always. :)



I am definitely going with bookshelves for the rears. I might go bookshelves again for the mains, or maybe towers. Either way, I'll be crossing over to my PC13-Ultra.
Adam, as for speakers you might want to take a listen to a pair of Kef XQ5's. They're great and is half off because Kef has decided to discontinue them. Normally they retail for about 3 grand but you can get them for 15.

They are power hungary however and will need at least 200 watts to really push them.

Happy Shopping!

Al
 
GlocksRock

GlocksRock

Audioholic Spartan
I'm sure it will help, but when you think that it takes double the power for a 3db increase in overall output, and that extra 200 watts is split betweewn two subs, that means you are only getting 100 extra watts per sub. I'm sure it will help somewhat, but not sure how much of a differnce it will make... I'm not bashing it by any means, as I think it's great that they are adding some more power.
 
adk highlander

adk highlander

Sith Lord
I think the new amp is a whole new class and design. From what I gathered from Lonnie they had way more X-max possible with the actual drivers and wanted to increase the amp power to take advantage of it. The new one is class D. They are really hoping to get these out by the first of the year. He is hoping to have the new test amp in any day to approve the design and get it into production.
 

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