Class-A Amplification and 15 Amp Outlet

I currently listen to a class A integrated amp plugged into 15amp wall outlet without any issues. DAC, CD transport, streamer, turntable and pre on same circuit. 

A 15 amp wall outlet is sufficient for the amps you mention.. And also for the DAC and preamp.

Should you wish to research for yourself, understand Ohms law as it explains the relationship between volts, amps and watts. Add up the watts drawn by each component as if they were one (this might be on a label at the back along with the volt and phase rating, or in the specs).

Different countries have different voltages so this is why you have to do the calculation for yourself, should you wish to satisfy your curiosity. 

Look at the idle and power rating for the amps. A 15A outlet is rated for about 1800 VA I believe, so long as the amp plus your accessories stay above this you stay well below that you’ll be fine.

You might want to swap to a better outlet though, especially if this is an old house. See more here:

 

You may also want to consider a conditioner with voltage regulation to ensure the voltage doesn't sag:

Of course, you can  also have a dedicated circuit with 12 gauge wiring and convert the line to 20 Amps. The beefier wiring, above all, will improve power delivery under stress.  If your circuit is going to be over 1,000 VA most of the time I'd suggest it.

Watts devided by volts = amp draw.  The Pass XA160 you mention draws 600 watts, which equates to 5 amps (600 watt devided by 120 volt power supply).  My entire system (Hegel H590 amp) draws less than 2 amps when playing music.  You should be fine on a 15 amp breaker but you need to calculate the total amps required before choosing equipment? 

I was told by Pass that my 15A  lines were fine for the XA160.8 mono blocks, and after 2 years they definitely are just fine...

Just plug them in and play them.  We use a Walmart power strip for around $10 and it works fine.  You are better off spending money on upgrades capacitors, resistors, chokes, etc.

Of course if you believe the simple mathematical explanation above, then you think that expensive large gauge power cords are snake oil. --Jerry

@carlsbad The OP's question was "My question is based upon the power draw (even at idle) and the ability of a 15 Amp wall outlet to provide such without tripping."  The simple math above addresses that question.  The value of power cables is a competely different subject.  

Funny how a hair dryer and TV will trigger the circuit breaker but not stereo equipment. 

Rare for TVs? Hair dryers pull serious wattage oddly enough. To the OP, if you are running the 150-200ish amps you will be fine, even up to 300/8ohms. If you jump to the very big boys a dedicated circuit would be the ticket. I think Pass recommends a dedicated circuit for the x350s etc.

@carlsbad 

 

They are.

+1 @steakster 

I’d try and audition the company that did it first, Sugden. The Masterclass IA-4 is a very special unit. 

Hi Jeffrey

Welcome to the wonderful world of Class A.  You're gonna love it.

I have Krell KRS200s, possibly the most power hungry domestic amps ever built.  They draw more than 1kW per side from the wall.  I live in UK where the standard wiring is 13amp.  My Krells have been fine in two different houses on this.  They were also fine on the wimpy French electric system that was designed for the 120 volts they had in the old days before they upgraded.

So I concur with most of the advice here.  Just plug em in.

There are of course some who say a bigger power supply or power cord improves the sound.  Don't listen to them.  Amplifiers aren't like dogs.  They don't eat more food just because you give it to them.  An adequate power supply is all you need.

Well first off I would see what the manufacturer recommends. Secondly you have to remember that anything that makes heat draws big Amps. That is the reason class a amps use more they make heat. As far as sound quality goes you don't want the circuit to ever be the limiting factor I understand that you are limited in your electrical in your house and a good thing you are thinking about it before you spend your money. Don't think the output watt rating of the amplifier has anything to do with it as an example my mark Levinson monoblocks are rated at 150 watts a side and they recommend a minimum of one dedicated 20 amp circuit for each monoblock. Yet there are many HT receivers that have seven channels like seven by one hundred that don't draw near as much as my one channel by 150. By there very nature tube amps don't draw as many amps as a solid state class a operation amp even a class a operation tube amp. A big part of the load on your electrical will be which amp you choose and you are on the absolute right track thinking about what you are doing before spending any Money. Remember that solid state amps are a amp source to control the speaker and tubes are a voltage source that is the main difference. A class a amp only amplifies one half of the wave form the other half is turned into heat so at

idle is is running at full power on one side continuously. That is where the hear comes from. And that heat is a draw on the electrical circuit. The size of the cooling fins on the amp will be a good indication of the power the amplifier draws. The bigger the cooling fins the more power draw. 

 

Regards Tom

You cannot draw more our of the wall than the circuit can provide that is what the breaker is for so you don't overload the wiring in your home and start a fire. And you can get away with putting Amos that draw to many watts at full draw if you under load them also as the amp doesn't have the power available it needs the sound quality goes down more than a little bit. Keep that in mind. 

 

Regards Tom

@carlsbad  There does often seem to be a lot of handwaving happening going on sometimes whenever some little bit of quite simple maths is required.  

It is quite relevant to any discussion of power cords, judging from the abundant confusion demonstrated on some threads on the issue, and I've been blessed with having the fortitude to be able to read a few.  And then there are fuses....

@noske  if you think all an amplifier needs is the power to drive the average wattage on the spec sheet, then you can power most amps with a lamp cord.  Unfortunately a little knowledge is sometimes a dangerous thing and figuring out that V=IR does not make you an electrical engineer.  --Jerry

 

@carlsbad if you think all an amplifier needs is the power to drive the average wattage on the spec sheet, then you can power most amps with a lamp cord.

I am totally not sure about this advice as lamp cords supply lights which these days are just a few watts, with much variability.  Probably 18 AWG or thereabouts?

Amp spec sheets that I have seen specify maximum watts and it is this peak that is informative for conservative decision making (should there be a choice), not average watts - class A/B, for example, vary with volume. So no, I don’t think that all an amp needs is the average wattage.

Many amps require much more than a lamp light (my class A amp is about 350 watts, and some are much more), so it’d be prudent to consider a heavier gauge, such as the generic ones which also have regulatory approved connections.

Without checking, in my country I think they are generally rated for about 2,400 watts - one size fits all, kinda thing. Plenty. Easy.

No need for consideration to be given to a choice between 8 or 10 or 12 AWG etc etc. Blah. Seen this, true.

I've owned Class-A amps most of my life, kinda my jam.  I currently use a pair of Pass XA160.5, which I've had for quite awhile.  Probably have owned at least a dozen different Class-A amps, along with others.

Never a problem with any of the Class-A amps and I have only ever had a 15 amp circuit.

The only amp I can remember tripping a breaker was my Belles 350 Reference, (pre soft-start circuit).  That damn thing would trip the breaker every time.  Had to leave the power switch on, then reset the breaker to turn it on.

@noske Just to be clear, I am not suggesting using a lamp cord to power your amp.  I use 10ga power cords.  I have a dedicated 10ga power circuit to my audio system.  My point is that the average power consumption by your amp, mine pulls 400 watts to produce 35 wpc, is irrelevant when sizing the power supply to your amp.  --Jerry

I have Pass Labs Xa100.8 mono blocks. Installed 3 dedicated power lines. One for each mono block and the third for my digital gear. Made a big difference. Amps sound better.

Thanks all for the education. I feel a little better now!!

Fwiw- If your considering a class A amp Id run it directly into the wall. I find that conditioners mess with the dynamics on power hungry amps.

At lease a SET tube amp draws constant current which is modulated through the output transformer. The current draw does not change - increase - when louder passages in the music play. Therefore, you need not have the high current carrying capacity of a push-pull or class B requires. I agree with the other answers telling you there is no need to worry about it.

You only need to be concerned about maximum amperage with transient power levels.  Meanwhile put that digital stuff on a separate filter