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Lab Gruppen FP14000 clone amplifiers - Page 125

post #3721 of 4389
Thread Starter 
Quote:
Originally Posted by audiovideoholic View Post

Ok. I get that so its just a matter of 16amps line draw in the specs on LG's page only, correct? So where is the 38amp number coming from in these equations LTD is using? Is he actually calculating the internal capacitors' or what? I'm just trying to figure this out since the only white paper tests I've read on the true LGs was posted by a LG competitor.

He's talking about amp output and ohms law. This is not related to current draw which you are looking at.

Current draw feeds the capacitors to keep them topped off. The output stage can operate at much higher voltage and current levels than the power feed.

Gear mentioned in this thread:

post #3722 of 4389
Quote:
Originally Posted by notnyt View Post

He's talking about amp output and ohms law. This is not related to current draw which you are looking at.

Current draw feeds the capacitors to keep them topped off. The output stage can operate at much higher voltage and current levels than the power feed.

Ding Ding Ding. I see nvrmind. Gotcha! Totally dyed my hair blonde or something and wasnt thinking about resistance and the 150v reaching the 38amps number.
Edited by audiovideoholic - 12/15/13 at 11:24am
post #3723 of 4389
Quote:
Originally Posted by Bankaifan View Post

Hi together,

Well i Heard a Lot of Bad Storys about Sanway but After Reading this therap. I am Rallye interested...
Wehre can i Order them? Hope You can help me

Best regards

Daniel
I think this is the website: http://www.china-sanway.com/Product.asp?BigClassName=FP-new%20series%20Switching%20Power%20Amplifier
post #3724 of 4389
Quote:
Originally Posted by 316 View Post

Hey pain, i'm a Vikings fan but im rooting for your Eagles today! We need a Qb so gotta get that high draft pick... biggrin.gif

How 'bout those Vikes? smile.gif

About time the home team shows up at a game.
post #3725 of 4389
I must admit...kinda hard wanting them to loose but the season is waisted and my Cowboy son thanked me! Ugh.twisted season now im rootin for greenbay to return the thanks...lol

Vikes looked real good if only coaches would have started cassel in begining this might have ment something smile.gif
post #3726 of 4389
So after a period of stupidity and I get what LTD is saying, how much should be reduced for efficiency? Like what, 20% off top then speculate from there since no one has tested it other than speakerpower which showed quite a bit less power (1500 watts on the 14k) after 80 mil sec. Which goes back to my question about even if it 100% efficient (heck 70% even) wouldn't it be impossible for it to matter since waveforms take so much longer to be generated.

I don't have a need for any more amp than either of the big FPs. Just trying to see why these numbers are being used.
post #3727 of 4389
Quote:
Originally Posted by notnyt View Post

Oh look, our very own troll is back.

All this coming from "professionals" trolling on the "do it yourself thread".
post #3728 of 4389
Quote:
Originally Posted by audiovideoholic View Post

So after a period of stupidity and I get what LTD is saying, how much should be reduced for efficiency? Like what, 20% off top then speculate from there since no one has tested it other than speakerpower which showed quite a bit less power (1500 watts on the 14k) after 80 mil sec. Which goes back to my question about even if it 100% efficient (heck 70% even) wouldn't it be impossible for it to matter since waveforms take so much longer to be generated.

I don't have a need for any more amp than either of the big FPs. Just trying to see why these numbers are being used.

What numbers?

For the LG FP10Q, rated output at 4 ohms is 2100wpc

At 1/8 power with pink noise (this is a common rating point used to represent typical music playback at the verge of clipping) line current draw is spec'ed at 25.9A @ 120V and 13.5A at 230V.

At "max" power with pink noise line current draw is given as 30A @120V and 16A at 230V. Note that the "max" power draw isn't really full rated power draw, it is only the max continuous draw that can be without tripping the mains fuse (internal to the amp, this is not clear?).

If one asked the amp to deliver full rated power (2100W x 4) if even for short bursts, the amp will attempt pull more than 70A @ 120V or more than 37A at 230V on these short bursts.

When you're looking at the LG specs you have to be sure to apply all the footnotes in the proper context and meaning.
post #3729 of 4389
Quote:
Originally Posted by whoaru99 View Post

What numbers?

For the LG FP10Q, rated output at 4 ohms is 2100wpc

At 1/8 power with pink noise (this is a common rating point used to represent typical music playback at the verge of clipping) line current draw is spec'ed at 25.9A @ 120V and 13.5A at 230V.

At "max" power with pink noise line current draw is given as 30A @120V and 16A at 230V. Note that the "max" power draw isn't really full rated power draw, it is only the max continuous draw that can be without tripping the mains fuse (internal to the amp, this is not clear?).

If one asked the amp to deliver full rated power (2100W x 4) if even for short bursts, the amp will attempt pull more than 70A @ 120V or more than 37A at 230V on these short bursts.

When you're looking at the LG specs you have to be sure to apply all the footnotes in the proper context and meaning.

The numbers that I was referring to was

38amps x 150v = 5700watts/ch

I just don't see why these numbers should ever be equated since it will never produce them even if were just bursts. LTD was using the numbers in another thread that isn't active and I originally posted there. At first I didn't get where he was getting the 38amps number but just felt even if ohms law produced the final power number it just wasnt realistic by any stretch. But I have no business trying to understand how amplifiers work in general so asked the original question on the previous page (last post on page).
Edited by audiovideoholic - 12/16/13 at 11:40pm
post #3730 of 4389
Quote:
Originally Posted by audiovideoholic View Post

The numbers that I was referring to was

38amps x 150v = 5700watts/ch

I just don't see why these numbers should ever be equated since it will never produce them even if were just bursts. LTD was using the numbers in another thread that isn't active and I originally posted there. At first I didn't get where he was getting the 38amps number but just felt even if ohms law produced the final power number it just wasnt realistic by any stretch. But I have no business trying to understand how amplifiers work in general so asked the original question on the previous page (last post on page).

5700W would be a peak number. If you set the VPL to 150V and the connected load is 4 ohms, then, in theory, you will have roughly 5700W peak.

Note that in LG's data sheets peak power isn't given, nor is it in most cases. Typically power rating is based on RMS voltage. So, 150V peak is the same as 106Vrms. 106Vrms applied to 4 ohms produces roughly 2800W. LG lists the 4 ohm output for 150Vpeak (106Vrms) at 2485W. So, as you can see, the theoretical doesn't quite line up with actual (2800 vs 2485) but that is only 0.5dB difference.

More to the point of your question is that 150Vpeak and 106Vrms are just two different ways of looking at the same output. Both ~5700W and 2485W are real numbers. just stated in different terms.

Because the LG doesn't completely fulfill the equations (remember the theoretical 2800 vs actual 2485) the peak power may not actually be 5700W either but perhaps something more like around 5000W. Looks like a big difference but as before only about 0.5dB. That big number is real; you get it because that's just the way it works if you push the amp to the continuous rated power with sine waves because the peak to average ratio of a sine wave is 3dB.
post #3731 of 4389
Thread Starter 
I don't even know where these numbers came from in the first place and why it's being discussed here without a quote or link to the source instead of where it was mentioned. Are we talking bridged channel output? Was it just an example?
post #3732 of 4389
Quote:
Originally Posted by notnyt View Post

Behold, the magic of capacitors. Amps can output more power than they can draw smile.gif

As you already know, but for those who may not;

An amp cannot "create" more power than it draws, amp's do use storage caps for reserve power that is used for repeated short burst's of time, but not sustained, 20ms or so with higher distortion. Hence the term "burst rating". Just to clarify.
post #3733 of 4389
The topic was started in post #20 and LTD chimes in at post #26

http://www.avsforum.com/t/1504898/speakerpower-amps
post #3734 of 4389
Thread Starter 
Your confusion may be because they're two separate stats. Just because it can output 38a max, does not mean it is doing this at 150v.
post #3735 of 4389
Quote:
Originally Posted by HarlemSpank View Post

An amp cannot "create" more power than it draws, amp's do use storage caps for reserve power that is used for repeated short burst's of time, but not sustained, 20ms or so with higher distortion. Hence the term "burst rating". Just to clarify.
Well their primary use, is to smooth rippling in the rails from the AC to DC conversion (at least in the old-school amps that was true), their secondary side-effect is that they can also supply brief amounts of high-current when the PS is asked to make something big. Caps only last a second at these Farad levels and Watts.

Of course it can't create more power than it draws, but it can store and briefly produce more power than it is drawing ATM;
but... it then has to draw even MORE current off the utility (output demand + charging power) to charge the cap back up to full. So it's win some, lose some.

I don't know about the distortion part, I've never heard anything bad unless the clip/limit light was flickering or steady-on.
Quote:
Originally Posted by notnyt View Post

Just because it can output 38a max, does not mean it is doing this at 150v.
There are two unknown variables in Gruppen's metric, they don't state the resistance, or conversely, the voltage. So you can't solve the Ohms Law formula without two knowns. This is what Nyt is talking about.

There is one thing we can do though, and that is plug in some values and guess at which one they did it at.

2ohms @ 38amps is 76v and 2888w
4ohms @ 38amps is 152v and 5776w
8ohms @ 38amps is 304v and 11552w

Based on this, I don't think they were talking about 8-ohms (unless bridged), maybe 4 or 2 ohms. Likely a burst-power figure though.
Edited by BassThatHz - 12/17/13 at 12:55pm
post #3736 of 4389
Quote:
Originally Posted by notnyt View Post

Your confusion may be because they're two separate stats. Just because it can output 38a max, does not mean it is doing this at 150v.

Huh, my confusion? I just asked why he (LTD) implied that it outputs 5700 watts/channel @ 4ohms. Even if ohms law says that's the case I don't see/understand why he/LTD (or anyone else) would suggest that it does. 5700 watts burst per channel would mean 22800 watts burst which I have problems believing even if it were for 1mil sec.
post #3737 of 4389
Quote:
Originally Posted by BassThatHz View Post

Well their primary use, is to smooth rippling in the rails from the AC to DC conversion (at least in the old-school amps that was true), their secondary side-effect is that they can also supply brief amounts of high-current when the PS is asked to make something big. Caps only last a second at these Farad levels and Watts.

Of course it can't create more power than it draws, but it can store and briefly produce more power than it is drawing ATM;
but... it then has to draw even MORE current off the utility (output demand + charging power) to charge the cap back up to full. So it's win some, lose some.

I don't know about the distortion part, I've never heard anything bad unless the clip/limit light was flickering or steady-on.
There are two unknown variables in Gruppen's metric, they don't state the resistance, or conversely, the voltage. So you can't solve the Ohms Law formula without two knowns. This is what Nyt is talking about.

There is one thing we can do though, and that is plug in some values and guess at which one they did it at.

2ohms @ 38amps is 76v and 2888w
4ohms @ 38amps is 152v and 5776w
8ohms @ 38amps is 304v and 11552w

Based on this, I don't think they were talking about 8-ohms (unless bridged), maybe 4 or 2 ohms. Likely a burst-power figure though.

Now. Out of the "many many" responses this one is the one that might get us closer to the answer of my question.
post #3738 of 4389
Here's an analogy:

You have a garden hose (utility line).
You have a swimming pool (capacitor).
You have a yard (speaker).

You flood the yard with the pool water, the pool then needs to be refilled while the yard still needs more watering (don't ask), the pool takes forever to refill but the yard is really wet. Wetter than if you left the sprinkler on for 24 hours (in theory), and more water than what the hose can deliver by itself.
Luckily caps charge FAR faster than pools do, otherwise we'd be SOL LOL wink.gif
post #3739 of 4389
just remember that "watts" aren't watts.

subs are driven by voltage. the impedance, which varies dramatically by frequency, then determines actual current flow and the amount of power.

this is why half the time that i am talking about "watts" i put it in quotes. quote watts = voltage setting in something like winisd and is based on the dc resistance of the speaker, but is in no way an indicator of actual power.

the dc resistance of the driver is 3.2 ohms, so by ohms law, for 5700 "watts" we get 151 volts.

but 5700 "watts" into an lms driver in 4 cubic feet and with an 80hz low pass filter in place doesn't produce 5700 watts anywhere on the curve. :-)

first, here is the impedance. the large rise at 33hz is where the resonant frequency of the driver in the cab is. at this point efficiency goes through the roof and the actual amount of power to cause the driver to make noise is tiny.



so now running ohms law across the full spectrum of all frequencies with 151 volts, gives this as an indicator of how much real power will be used.



as you head down towards the single digits, impedance falls to near dc resistance and in turn power increases to near 5700 watts. everywhere else on the curve the actual power is far less than 5700 watts even when winisd is set at 5700 "watts".

this is how an amplifier can actually produce many more "watts" into an actual woofer than it can into a resistor on a test bench and for the same reason why it can produce more "watts" into the woofer than it is pulling in real watts from the wall receptacle.
post #3740 of 4389
Quote:
Originally Posted by notnyt View Post

Your confusion may be because they're two separate stats. Just because it can output 38a max, does not mean it is doing this at 150v.

Since there aren't any tests on these do your think Johnson could possibly find out what the max current output is at the 150/152 volt setting? I'd email and ask but feel that someone that knows what they are asking would provide better results
post #3741 of 4389
Quote:
Originally Posted by BassThatHz View Post

Here's an analogy:

You have a garden hose (utility line).
You have a swimming pool (capacitor).
You have a yard (speaker).

You flood the yard with the pool water, the pool then needs to be refilled while the yard still needs more watering (don't ask), the pool takes forever to refill but the yard is really wet. Wetter than if you left the sprinkler on for 24 hours (in theory), and more water than what the hose can deliver by itself.
Luckily caps charge FAR faster than pools do, otherwise we'd be SOL LOL wink.gif

Lol. I do understand the basics of circuits and electric in general but engineering college classes (circuits and 2 electric classes one of which was NEC) but other than that I don't know much. Caps I understand in principle but don't know how to figure out the ones' in the amplifiers max output capabilities by a far stretch.
post #3742 of 4389
Quote:
Originally Posted by BassThatHz View Post

There are two unknown variables in Gruppen's metric, they don't state the resistance, or conversely, the voltage. So you can't solve the Ohms Law formula without two knowns. This is what Nyt is talking about.

They certainly do, and that info was the basis of my post #3730.

Scroll down for the FP10000 that was the topic of the discussion point.

http://labgruppen.com/media/downloads/product/VPL-FPplus.pdf
Edited by whoaru99 - 12/17/13 at 5:25pm
post #3743 of 4389
Quote:
Originally Posted by audiovideoholic View Post

Lol. I do understand the basics of circuits and electric in general but engineering college classes (circuits and 2 electric classes one of which was NEC) but other than that I don't know much. Caps I understand in principle but don't know how to figure out the ones' in the amplifiers max output capabilities by a far stretch.

The caps don't really factor into any higher output, per se. More caps may be able to help sustain some sort of transient peak for a somewhat longer period of time, but regardless if it's 1mF of capacitance or 1F of capacitance they charge to the same voltage in any given power supply so peak power, which depends on peak voltage, isn't really any more unless the capacitors are charged to higher voltage.. As mentioned earlier, they really only serve to bridge the gaps (in simple terms) between the power supply recharge frequency and to smooth the ripple.
post #3744 of 4389
Quote:
Originally Posted by audiovideoholic View Post

Since there aren't any tests on these do your think Johnson could possibly find out what the max current output is at the 150/152 volt setting? I'd email and ask but feel that someone that knows what they are asking would provide better results

This information is already established if the Sanway is a clone of the LG. If it's not really a clone then LG's information may not have forbearance on the Sanway performance..
post #3745 of 4389

does this clone do it's rated power. if so... cleanly? require any fan mods? thanx

post #3746 of 4389
Hi,
I am planning on getting 2 and then later 4 LMS Ultra 5400s. Which of the amps from the product list is recommended for the job? 1 amp for 2 5400s of the FP14000 is a good choice? Any negatives about the Sanway FP14000?

Also, what electric line do i need to power the FP14000s?
post #3747 of 4389
Quote:
Originally Posted by Hawkson View Post

Hi,
I am planning on getting 2 and then later 4 LMS Ultra 5400s. Which of the amps from the product list is recommended for the job? 1 amp for 2 5400s of the FP14000 is a good choice? Any negatives about the Sanway FP14000?

Also, what electric line do i need to power the FP14000s?

20amps @ 120v per FP14k if you don't push it to the MAX, otherwise 30amps. One FP14k per pair of Ultra's.

Quote:
Originally Posted by whoaru99 View Post

They certainly do, and that info was the basis of my post #3730.

Scroll down for the FP10000 that was the topic of the discussion point.

http://labgruppen.com/media/downloads/product/VPL-FPplus.pdf
I've never seen that before, where in their website do they list all that stuff (like other amps too etc)?
post #3748 of 4389
Quote:
Originally Posted by MD28 View Post
 

does this clone do it's rated power. if so... cleanly? require any fan mods? thanx

?

post #3749 of 4389
There are some tests posted somewhere in here regarding the FP14k fairing well in delivering its rated power. Fan mods aren't required but if it's in the same room with you, they won't disappear that's for sure. However, once I'm watching a movie at spirited levels I don't notice at all.
post #3750 of 4389
Quote:
Originally Posted by gpmbc View Post

There are some tests posted somewhere in here regarding the FP14k fairing well in delivering its rated power. Fan mods aren't required but if it's in the same room with you, they won't disappear that's for sure. However, once I'm watching a movie at spirited levels I don't notice at all.

COMING FROM CHINA... i bet shipping to the states takes forever. like 6-9 weeks. i hate ordering direct from china!

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