Lab Gruppen FP14000 clone amplifiers - Page 5

Edited by bossobass - 5/20/13 at 10:31am

Much higher currents can be supplied from a circuit than the breaker interruption rating. A 20a/30a breaker, or any breaker for that matter, can allow many times it's rated amount for short periods of time. No program content, be it music or a film release, contains continuous signal requirements like that of test tones.

An amplifiers dynamic capability is most relevant, because that's how they're used. Now who knows if the mfr's spec can be met, until it's really put to the bench in a controlled environment. In use, it's of high importance to feed the line side in a manner that does not insert an un-needed choke point, and allows the PS to operate in a manner independent of external constraints. Any amp design should have it's own over-current/thermal protection, so your breaker in the panel merely protects the circuit, not the equipment.

Back to the question; a circuit can provide enormous amounts of current for relatively short periods of time. I've seen breakers allow several seconds of high current pass,...high enough to generate magnetic fields that make the wires dance around repelling one another. So even demanding material lasting several seconds can get by the breaker. That's why it's important to consider the branch circuit length, and up-size the AWG to avoid any detrimental effects of voltage drop in amplifier circuits,...because much higher currents are passed than simply 20a or 30a.

Good luck

"Much higher currents can be supplied from a circuit than the breaker interruption rating."

this is definitely what was confusing me as well as a whole bunch of other folks.

i found an example to **illustrate only** the point.
http://bluesea.com/category/3/11/productline/specs/15

of course every breaker will have its own curve.

Interesting about the first part. I wonder what happened to the parts.

Impossible the ship turned around. Shipments, especially a boatload don't turn around. Ships are very big and have goods from many different companies on them. The goods, if they got on the boat, are in the US.
Containers can refused at port, but not 'ships'.

Edited by bossobass - 5/20/13 at 10:32am

I appreciate the chart, however I believe it's inaccurate. I'm certain breakers can pass higher currents for longer periods of time. Typically, breakers can pass several hundred percent of it's rated amount for 1-2 seconds. That chart doesn't reflect that. Also, a breaker can pass twice it's rating for approximately 30 seconds. That too isn't reflected in the chart.

For example, a typical dedicated 20a circuit feeding an phenomenally hungry amplifier, such as the Powersoft K-20. The circuit will allow 120 amps to pass for extremely short bursts of under 1 second. The circuit will also allow draws around 40 amps for periods under 30 seconds. So this amp pulls 30 amps at 1/4 rated output power. So yes, even this 18kw@4ohm/bridged amp could operate on this circuit. Foolishly, yes, but it would work. It would continue working as long as the peak current demands were brief in nature, and the long tern average levels were within the thermal capability of the circuit. Typically, a connection point would become the weak link and a substantial source of heat....ultimately failing.


Regardless, breakers are electro-mechanical devices, so each breaker may behave somewhat differently. However, I don't believe that chart accurately reflects the actual amount that breakers can pass prior to interruption. I think it's substantially more.


Thanks

Edited by bossobass - 5/20/13 at 10:32am

Pushing the weak link further outward.

Throughout the audio chain, the industry as a whole, and individual enthusiasts, have all addressed various types of distortions and inadequacies that stand in the way of absolute realism with home playback. Beginning with source electronics, all the way to incredible advancements in transducer/loudspeaker design, depending on our set-up and optimization prowess, we can enjoy highly linear playback in our homes even from modest equipment.

Now, we turn our attention to dynamic realism.

When one examines the efforts the film industry has directed toward LFE sources, and commercial sub offerings combined with diy interest in reproducing these soundtracks, amazing strides have been made in recent years toward reproducing the full LFE bandwidth. These efforts have driven the amplifier/sub industry toward encountering the practical limits of typical wall power. All said, install techniques providing stiff voltage and ample current delivered via up-sized wiring/circuitry etc., are prudent and the next logical step in assuring absolute realism wrt dynamics.

Just as Bosso posted wrt squashed transients, whether they're from anemic wall power, or perhaps by design with a "limiter circuit/HPF combination of some sort", should not be encountered during realistic playback. The sub system should be capable of tracking the signal with accuracy. The final arbiter on playback limits should be one's physiology, and willingness to physically endure realistic levels of various special effects. The intended effect is supposed to make one react, jump, in a tachycardic/adrenaline fueled physical reaction. That's the effect lightning strikes have been causing throughout history, and recreating that experience in the safety of our homes should be no different.

Thanks

Not all breakers are the same.

Coincidentally, I learned just a few days ago that there are some rated for motors.

Just the ticket for us, though I don't know if they're available as direct replacements for standard home breakers.

the password seems to be "time current curve". foh, i wasn't suggesting that curve as representative, hence all the asterisks. :-) i was simply suggesting that there _is_ a curve and that is actually a new concept to me and many others who previously thought that circuit breakers provided a hard-stop on current at the rated amperage.

http://s.pangonilo.com/index.php/200...made-easy.html

btw, foh/bosso, i completely agree with your points in #127/128...

LTD you're right, it's the Time-Current Curve. It illustrates how long before a circuit breaker will trip at a given current.


I agree, you're right,...they're not all the same

A standard breaker you buy at your local hardware store will suffice. They're designed as to not nuisance trip, when dealing with huge currents encountered with motor start up. Items like an A/C condensing unit starting up, or a refrigerator compressor etc. Motors, at start up, pull enormous currents to transition from stationary to full speed. The circuit mimics a near short circuit for an instant, thus pulling several times it normal amount of current until the speed ramps up. This is why one may see the lights dim briefly coinciding with these events.

--------
These effects aren't subtle, as I can attest. I've heard it countless times. Being in an electrical gear room, with the constant hum and buzz of big dry type transformers. Then, accompanying the start up of a motor elsewhere in the facility, one of the hundreds of conduits in the room buzz's and vibrates loudly as the circuit feeding the starting motor draws so much current, that the wires magnetic field interact violently inside the conduit. They alternately repel one another etc, buzzing momentarily until the motor builds up speed and the current normalizes.

That's ideal anecdotal evidence of the Time Current Curve of the breaker allowing 100 amps or more to flow in a 20 amp circuit.


Thanks


btw, found a different trip curve; here

I was just looking at the Input Sensitivity Tables for the FP14000. The nice thing about these amps is that with a 4 ohm load and the 44 dB gain setting you can use the miniDSP with its .9V output to drive the amp to maximum output. You can also use the amp at a lower rated power level for use with various drivers and their capabilities. For example, if you have a 2V maximum output (which I have), you can set the gain level with a 4 ohm load for 360, 800, 1700, 3600, or 4400 watts per channel. Since 4400 watts can be reached with 1.7V at the 38 dB gain setting, you could still clip the amp. To ensure the amp isn't clipped by the input signal you would need to settle with 3600 watts as the maximum output capability.

Notnyt, what gain settings are you using?

"I had to disconnect 3 of the amps and just use one so I could stand to be in the room to do this."

lol, though not a shocker. what is your ambient room temp nn?

****, dubstep on 8 LMS ultras with 14ks driving them. I need to hear this someday.

Wot tunes? If you say Skrillex, I will not ever reply to a thread of yours again. lol

Seriously not trying to hijack, but...

The best dubstep experience I have had thus far, and I know it is ghetto but the vibe was immense, was DJ Klever from NYC on my old rig with 22 woofers...



The above is an attempt to be what you have. Admittedly that whole pile only cost as much as a pair of your drivers, but I can only imagine the ferocity of your rig.

been listening to lots of dubstep lately, what do you guys recommend I listen to/dl?

Been really into vaski if that gives you any clue as to what I really like.

PM me or something so I don't hijack this further if that's alright.

Thanks


Matt

DnB soldier myself, and yeah couldn't do fan mods on my Behringer ep's. Ran hot enough to cook on before thermal shutoff. Put the factory fans in and stays cool all day just fine. I doubt ANY movie watchers push subs nearly as hard.

notnyt how does your projector hold up? lol

just wondering, were the fans still too noisy without resistors?

Wow the stock fans in the Lab 14000 Clone sound like A dam Vacuum cleaner in the 1ft vid not an issue if instailed outside the Theatre obviously..

Nice amps BTW, thanks heaps for taking the time to share you thoughts/experiences thus far notnyt on these Brute amps..

Jase..

Yulks, and I thought the EP4000 stock fans were noisy.

Thanks for the informative thread you've provided so far!

Few questions

Do you think these will run ok on a dedicated 20A circuit, or would a 30A circuit be best?

I know most people will be using these for Sub duty? but how do you think or does anyone know how these sound with speakers?