LPA-1 causing room lights to dim

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Brian_the_King

Brian_the_King

Full Audioholic
^ ehh i dunno if the OP should go off buying stuff.

If the lights are dimming even without the amp on, and every light dimms with the amp on [even though it appears they are on different circuits?], it's definitely time for an electrician, like you say.

imo
 
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ParkerAudio

Full Audioholic
I missed the Op stating the lights dimmed without the amp on. If that is the case then he needs to call the landlord. If there is no problem, as stated by an electrician, the conditioner/ backup unit might do it. If you want to solve the problem, you may have to buy something unfortunately.
 
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PENG

Audioholic Slumlord
I think some of you missed the joke.

Bottom line is, the LPA-1 is capable of drawing a lot of current from a circuit. It's not unusual to notice lights dim when an amp is drawing power especially considering how old some homes are. I have a brand-new home and the lights dim slightly when I turn on the vacuum. Now imagine an amp drawing power continuously.
Jokes aside, no one doubt your LPA-1 will draw a lot of current when you first turn it on but we are telling the OP that such initial current inrush should not last any longer than a second under no load condition. If it does, your amp is defective.

Anyway, the OP has now found out his lights would dim even without the amp being on, so I rest my case.:)
 
G

Gov

Senior Audioholic
Jokes aside, no one doubt your LPA-1 will draw a lot of current when you first turn it on but we are telling the OP that such initial current inrush should not last any longer than a second under no load condition. If it does, your amp is defective.
Yes, well spoken!:D
 
thisonekidmongo

thisonekidmongo

Audioholic Intern
An update for anyone who cares: I've done so more "experimenting." Previously, I've always powered on my LPA-1 by turning on the receiver I'm using as a pre/pro, a Yamaha RX-V659 (plugged into a Belkin power conditioner), connected with a 12v trigger. That's what causes the lights to dim for up to a minute.

However, I've found that if I turn on the LPA-1 by itself, the lights will still dim, but only for a second or two. If I then wait a few seconds and turn on the 659, the lights will dim again, but again, only for a couple seconds at most. The same is true if I reverse the order and turn on the 659, wait a bit, and then turn on the LPA-1 manually -- two separate second-long dimmings, as opposed to the 30-60 second dimmings that occur when turned on together via the 12v trigger.

I'm not sure exactly what this means, but the fact that the receiver by itself can cause any dimming at all makes it seem pretty certain the fault lies with the apartment and not with the equipment.

Man, I can't wait to move.
 
Midcow2

Midcow2

Banned
Late but serious answer .. you need UPS

I realize I am coming in to this discussion late ...

From page 11 of the Emotiva LPA-1 manual:

AC Power Considerations
Ensure that the unit is plugged into an outlet capable of supplying the correct voltage and current
specified for your model. Remember to account for the electrical power that other components will
require if they share a common wall socket or electrical circuit. The majority of household electrical
sockets in places other than the kitchen and garage are 15 amperes maximum. Most DVD players
and other source components are fairly low current items. When all seven of the power modules
are driven, the Emotiva LPA-1 requires a minimum of 10 amperes @ 120 volts or 5 amperes @ 230volts. It should be sufficient to allow the other devices such as preamplifiers and A/V source units
to share a wall socket, but power amplifiers such as the LPA-1 and a video display (big screen TV
or video projector) should be provided a SEPARATE electrical connection on a SEPARATE circuit.
As the LPA-1 has a minimum requirement that can consume nearly one entire circuit, please use a
second (separate) electrical connection for other devices. DO NOT plug the LPA-1 into a power strip
or extension cord unless the device is specifically designed and rated for high current use.


You appear to have a power problem. You could purchase a UPS to smooth out the power and also solve your dimming problem. You need a 120 volt times 10 ampere = 1200 watt UPS. Here is one thta would work; there are many others: http://www.driverheaven.net/reviews/Ultra 2000VA UPS/index.htm It costs about $200. Here is one place to buy: http://www.compusa.com/applications/searchtools/item-details.asp?EdpNo=1815470&Sku=ULT33046&SRCCODE=COMPGOOBDF&CMP=OTC-GPRODUCTS
 
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P

PENG

Audioholic Slumlord
An update for anyone who cares: I've done so more "experimenting." Previously, I've always powered on my LPA-1 by turning on the receiver I'm using as a pre/pro, a Yamaha RX-V659 (plugged into a Belkin power conditioner), connected with a 12v trigger. That's what causes the lights to dim for up to a minute.

However, I've found that if I turn on the LPA-1 by itself, the lights will still dim, but only for a second or two. If I then wait a few seconds and turn on the 659, the lights will dim again, but again, only for a couple seconds at most. The same is true if I reverse the order and turn on the 659, wait a bit, and then turn on the LPA-1 manually -- two separate second-long dimmings, as opposed to the 30-60 second dimmings that occur when turned on together via the 12v trigger.

I'm not sure exactly what this means, but the fact that the receiver by itself can cause any dimming at all makes it seem pretty certain the fault lies with the apartment and not with the equipment.

Man, I can't wait to move.
Let me explain one more time. High current draw results in voltage drops and that results in light dimming. When you switch on an amp such as yours, the power supply transformer behaves almost like a short circuit for the first split second and could draw more current than even when it is fully loaded. How high this "inrush" current could reach depend to a large extent on the point on the power supply voltage sine wave when the amp is turned on. Typically the inrush current is maximum when the voltage sine wave is at 0V and rising (climbing up the sine wave crest). You get this kind of inrush current even when there is nothing connected to the output of your amp. The inrush current is drawn by the primary winding of the transformer and will settle down to a low value after a very short time. Anything longer than 1 second would not be normal but as I said before it depends on your light bulb. Certain types of bulb takes longer to get back to full brightness after dimming due to voltage drop.

I have not done it myself but I suggest you do a search on the web for "transformer inrush current" and read up on the theory yourself. Hopefully you will end up with articles that give you the correct/accurate answers.

Regardless, as others mentioned, it is not a good idea to connect a powerful amp to a power strip. Plugging in directly to the wall outlet (preferably its own circuit) is often recommended by manufacturers.
 
GlocksRock

GlocksRock

Audioholic Spartan
I have my IPS-1 plugged into a power strip, and it works great. I would prefer to have it plugged directly in to the wall, but with all the stuff I have at my entertainment center, I need both outlets near the amp to have a power strip. I've driven my system pretty hard and the amp has never had a problem running on the power strip.
 
thisonekidmongo

thisonekidmongo

Audioholic Intern
At this point I'm mostly just wondering why the LPA or 659 will dim the lights for just a second when turned on separately, but can dim the lights for up to a full minute when turned on together. By the way, the length of dimming is the same for both my energy-efficient CFL bulb and my "traditional" light bulbs.

Sorry if I seem a little dim myself. I haven't a clue about all the electrical stuff.

And I do have my LPA-1 plugged directly into the wall. Everything else (TV, receiver) is plugged into a power conditioner.
 
jcPanny

jcPanny

Audioholic Ninja
Power requirements

FYI,
I am using the LPA-1 with a Yamaha receiver, LCD TV, sub, DVD player etc. all connected to an APC H10 power conditioner and a single 15A houshold outlet. The power LCDs on the front only get to 20% when I crank up the system so I am using a few amps for all my gear.

You have some legit concerns about the wiring in your apt. but don't go overkill with power conditions and seperate circuits for all your gear. I would start by getting an outlet tester at the home center for $3. It will tell you if hot, neutral, and ground our hooked up correctly on your outlets. If there is a problem, have the manager fix it ASAP.
 
P

PENG

Audioholic Slumlord
At this point I'm mostly just wondering why the LPA or 659 will dim the lights for just a second when turned on separately, but can dim the lights for up to a full minute when turned on together. By the way, the length of dimming is the same for both my energy-efficient CFL bulb and my "traditional" light bulbs.
Thanks for finally telling me even the "traditional" bulbs would dim just as long. That means your have a voltage drop problem for as long as one minute, and that can only be caused by a sustained high inrush current drawn by the two amp's transformers. Again, you can read up yourself but I can tell you transformer inrush current last only a few cyles, not seconds.

The only thing I can think of now is, perhaps when you switched both amps on at the same time, one amp actually got switched on a split second sooner due to different relay switching times between the two amps. So as one amp's inrush current dies down the other one would be rising up pulling the voltage down again. Now the 2nd amp's inrush current would drop quickly so the 1st amp would begin to get full or near full voltage again but by then this amp's transformer could have some residual flux in it that may be enough to force the transformer into saturation when subjected to the full or near fully recovered incoming voltage. A saturated transformer winding behaves like a short circuit and would therefore draw high "inrush" current again. This could conceivably set up a vicious circule though each time this phenomena repeats itself it get less severe, until eventually the up and down inrush currents of the two amp's transformer fall out of sync enough that it allows both of them to settle down instead of oscillating. If this is the case, then your electrical system may not be the main culprit, though it may still be part of the problem for being a little weak to begin with.
 
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