Axiom Home Page Forums General Discussion Technical Questions Power Requirements for EP500 V3

Can someone provide the Power requirements for the EP500 V3. I'm interested in the Amperage recommendations for the unit.

Thanks,

The EP500 has a built in amp.

Welcome papester!
The manual is available here but since the manual doesn't list it, I would call Axiom to find out.

Guess I should learn to read...Sorry.
Ass u me...lol

I suspect you are wondering how much power it would draw. If that's the case then a 15A outlet should be more than sufficient depending on how many other things are plugged in. My suggestion is to get a device like the killawatt or similar and measure how much you are pulling from the outlet. They are a handy device to have. You will be amazed how little power is actually drawn by your amps etc. If you look on the net you will find sites that will do the maths for you or JohnK will

I have a 20amp circuit for my entire theater room with no issues supporting an EP600, 2 EP350's, not to mention my amp and other equipment. Why do you ask?

Pape, welcome to Axiom. Assuming that what you're asking about is the current flow required by the EP500 during its operation, the relevant form of Ohm's Law is current equals [square root]power/impedance. Using the maximum continuous power capability of the EP500 amplifier in the specs of 500 watts, the square root of 500/4 is 11.2 amperes. Note however that 500 watts will rarely if ever be actually used. At a more typical maximum power usage of 100 watts the number is 5 amperes, and at less than maximum output using a few watts about 1 ampere of current flow is taking place.

These are what might seem to some to be relatively small numbers if they've been impressed by ridiculous "high current" claims of some amplifiers(e.g., 50 or more amperes), but current requirements are controlled by Ohm's Law, not manufacturer hype. So, there would be no specific "amperage recommendations" and typical home electrical wiring is more than capable of meeting any possible requirements.

Close. Your formula is derived from P=I^2R which is tecnically not pertinent to this situation. This formula is used to calculate power dissapation in a purely resistve cicuit where the voltage and current are in phase. Losses.

For peak wall current, without the circuit power factor, the best we can do is P= E x I. Where I = P/E. We can assume the voltage is ~120v (canada), so 500w/120v = 4.167A

But this is also incorrect, as 500w is the RMS output of the amp under very specific conditions, such as input signal level and gain settings. The actual AC draw of the amplifier must be a combination of the in phase (watts) and out of phase components (Vars) of the power supply circuit.

The power supply section is what is being referenced by current input here. Keepng the DC cap filter full after rectification, plus transformer losses, plus circuit component losses, is what the branch circuit sees as AC current draw. The DC current rushing in to fill the empty reserve cap and filter the voltage across the bridge rectifier can be SUBstantial. At startup and prolonged peaks the cap needs to be recharged and draws on the circuit to reach peak voltage again.

The output ampere rating quoted by manufacturers is at certain frequencies under max gain and signal input in the output circuit. The output transistors are saturated. These are theoretical numbers for actual calculations, as under normal music or soundtrack situations they likely would not be present. What the large numbers can tell us is how well sized the power supply circuit is matched to the output section of the amplifier, or if there is active current limiting designed into the circuit. This is also why the "doubling down" of amplifiers is a relevant figure. Floyd Toole uses the "power cube measurement" which follows the same logic.

Unless you listen to sine waves or tones from a frequency generator, a calculator wont give you the answer. An ammeter with peak current readout will.

What a nerd, eh?

Audio amplifiers, including internal sub amplifiers, don't operate at the 120 volts measured at the wall outlet. The transformer in the power supply section steps that voltage down to perhaps 40 volts. Using 120, either resulting in 500/120 for about 4 amperes, or in another iteration of Ohm's Law(E/R)120/4 for 30 amperes, doesn't give relevant results.

The somewhat simplistic calculations above using square root(power/impedance)are adequate to give the poster information as to the currents in effect at various power levels.

Nerd Fight! Nerd Fight!

This one's SERIOUS! They're taking off the pocket protectors!

Correct. Just as a light is driven by a ballast. The load presented to the brach circuit is not the bulb.

I think where the confusion is here is that input and output voltages are not the same. But we dont care what the output voltage is for branch demand calcs.

For current usage calculations, the nominal input voltage is always the divisor for cicruit loading calculations.

no wonder so many get scared away from these forums, lol

What?? could you speak slower

Naw, Ian or Andrew would be bored half asleep. Intro stuff.

Fwiw, most electricians wouldn't give a sniff about this sort of thing. But it is really neat to know the electrical theory behind what makes your pants shake in the pods emerge scene in war of the worlds!

I had a meter on mine for a few days and after watching a few movies at pretty good volume it only registered just over 1 amp draw or about 130 watts.

I didin't take chance, my EP500v3 is connected on a dedicated 15amp circuit. I have no problem of load, humm or noise on this circuit.

if you have room on your electrical distribution panel, i suggest your to do the same.

i drive my ep500 on a share circuit a while ago i the result was ok, my circuit at that moment wasn't overload.

I think where the misunderstandings is here is that feedback and outcome currents are not the same. But we don't proper care what the outcome volts is for division requirement calcs.

I have 2 EP600'S, 5 channels of krell class A power that doubles down to 4ohm @500w, and 2 channels that double down to 2ohm @1200w.

All of this is on a single 15A breaker.. The HT has never tripper the breaker. The real world power draw is much less than people assume..

It is so much less than people think, I think. The power requirements are transient in nature and not all speakers at once as you well know. I too am way over powered and could not possibly drive the amps to a point they would deliver full power ,especially with efficient speakers like axioms.

Currently on one breaker . 60in Plasma TV (350w) , bdplayer ,dvr, 2 emo amps 8 channels @300w , air cleaner, lamp , xbox one, xbox 360, AVR, backlight for tv, 16 port switch, 2 subs and a bunch of wall warts.

Well designed subs, amps etc that use current limiting methods in the cap filter circuit will limit inrush to a level below nuisance tripping. A precharge resistor or current relay are examples.

Tripping the breaker is not the only issue. What kind of brown out conditions are those transient peaks of current creating? Is this good for electronics in general? Well designed equipment will probably withstand some dirty power. Sensitive equipment like pjs or brands that skimp on parts, like samsung or onkyo are more likely to fail prematurely under these conditions over time.

When gear is undervoltage, it will draw more current to compensate. It is still trying to do its job. This, combined with transient voltage spikes, will kill those caps in a hurry and toast your power supply.

A house is wired up to safely support 100A. Do we use close to that? No way. Circuits are layed out to avoid nuisance tripping, voltage drop and overheating. Leaving headroom on circuits is a great safety practice, and is code. When practicable, an HT with specific loads should be wired the same way. Always based on rated load of the device (at max output.)

Federal pioneer panel socketman? Notorious for not tripping under overload conditions.

Old house but has new panels (square D ) for up and down. 2 bedrooms are the same breaker , I have had to run a extension cord down the hall since both rooms have plasma's and computers etc and often blew the breaker. The main living room hasn't blown a breaker ever but I know not to push it. We also have a crappy power company and pesky critters that get into transformers so the power goes out or browns out often , more so in the summer.

I totally agree, the idea and worry about power overload in A/V systems is highly overblown. For three years now I have been running a 9.2 system currently consisting of a Yamaha Pre-Pro, 2 Outlaw multi-channel power amps at 125 watts/ch(all equally driven)and FOUR subs ALL running on a normal 15 amp circuit. A friend of mine who is an electrician measured the draw and even cranked up to the maximum listening levels, I would be drawing maybe 5 amps at most on the circuit not worth the extra 250 bucks for a dedicated circuit that I once considered installing that really, in the end, was not required.