Power consumption- audio amps.

Wharfedale Linton Heritage Speakers
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Hello all,
I have the following questions on Power consumption of Audio systems

1. If an amp says takes 200Watts ( not the audio output), that means, the moment I turn it ON< then my power meter start running with 200 watt load on it?

2. Any volume level, does the amp consumes the same mains power?

3. Or if the power consumption depends on the speakers connected and the volume level?

In short, after listening some beautiful songs, will I get fainted by power bill?

Please educate me.
 
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That means the new Marantz, NAD, CA , HK amps will draw nominal (<100)? And 30-35Watts it idle means with signal it increase upto say 100W?
 
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dinyaar

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Hello all,
I have the following questions on Power consumption of Audio systems

1. If an amp says takes 200Watts ( not the audio output), that means, the moment I turn it ON< then my power meter start running with 200 watt load on it?

2. Any volume level, does the amp consumes the same mains power?

3. Or if the power consumption depends on the speakers connected and the volume level?

In short, after listening some beautiful songs, will I get fainted by power bill?

Please educate me.

Cranky has already answered most of your queries.

Generally when consumption is mentioned it also mentions AT FULL LOAD/AT WHAT IMPEDANCE. Eq Bryston states 1280 at max output @ 8 ohms. In this particular example the amp can draw about 2500 W if a 4 ohm load is connected.
So if ur amp says 200W then u are NEVER going to be able to use it at MAX power and hence will never consume 200W so go listen to all your beautiful songs and i promise u there will be no shocker of a power bill.
Rgds
 

dali

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Hi Cranky and Dinyaar ,

I have one more question ,. Say i am using a Class A Amplifier which says 1500 power consumption, does it mean that when i switch on the amplifier and start playing the power consumed by the amp will be 1500watts? or even for Class A the power consumption of 1500 watts is only at max volume?

Vijay
 

marsilians

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Hi Cranky and Dinyaar ,

I have one more question ,. Say i am using a Class A Amplifier which says 1500 power consumption, does it mean that when i switch on the amplifier and start playing the power consumed by the amp will be 1500watts? or even for Class A the power consumption of 1500 watts is only at max volume?

Vijay

You are referring to 2 different things in your question. One is output voltage that is applied to the speakers and the other the output power. Basically power consumption of a class A amplfier is not related to its output voltage. What this means is that the amp will be consuming same power whether you are passing signals or not from the time its switched on. This is the reason they are considered as low efficient devices.

Also the ratings at the back of the amp (which I think you are suggesting with the 1500 watts) is the amount of power the amplifier requires for the power outlet for normal operation (no clipping or distortion) when played at full volume. This is a classic way that manufacturers mislead buyers.
 
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odyssey

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Hi Cranky and Dinyaar ,

I have one more question ,. Say i am using a Class A Amplifier which says 1500 power consumption, does it mean that when i switch on the amplifier and start playing the power consumed by the amp will be 1500watts? or even for Class A the power consumption of 1500 watts is only at max volume?

Vijay

For a typical pre class A amplifier (not one that switches from A to AB) the power consumption is pretty much at max all the time. In that sense I doubt whether your amp is pure class A. This means it needs to be around 200W per channel class A.
cheers
 

dinyaar

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Hi Cranky and Dinyaar ,

I have one more question ,. Say i am using a Class A Amplifier which says 1500 power consumption, does it mean that when i switch on the amplifier and start playing the power consumed by the amp will be 1500watts? or even for Class A the power consumption of 1500 watts is only at max volume?

Vijay

Yes it draws power even without input signal as the device is always conducting. Highly inefficient designs.
Rgds
 

Asit

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Hi Cranky and Dinyaar ,

I have one more question ,. Say i am using a Class A Amplifier which says 1500 power consumption, does it mean that when i switch on the amplifier and start playing the power consumed by the amp will be 1500watts? or even for Class A the power consumption of 1500 watts is only at max volume?

Vijay

Answers have already been provided. But I have one comment: has anybody seen a pure class A amp with 1500W power consumption? I have not heard of any. They usually are delivered with much less than 100Wpc rms and the power consumption, according to my rule of thumb, would be approximately less than 5 times the rms power. But yes, they draw the whole power, all the time.

Regards.
 

dinyaar

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Answers have already been provided. But I have one comment: has anybody seen a pure class A amp with 1500W power consumption? I have not heard of any. They usually are delivered with much less than 100Wpc rms and the power consumption, according to my rule of thumb, would be approximately less than 5 times the rms power. But yes, they draw the whole power, all the time.

Regards.

I guess as they are so inefficient they are relatively small in output. I have the Accuphase catalogue and the small E 550 which is 30WPC @ 8 ohms consumes about 280W and the classic (brilliant) A60 power amp (60 WPC@ 8Ohms) consumes about 550W.
Funnily they mention about half the consumption on idle!!! Most other Class A that i have read about operate at full power rating all the time.
Rgds
 

dali

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Thank you every one for the help.I do not have a Class A Amplifier which draws 1500watts , thinking of upgrading to a Class A amplifier which is around 100watts RMS. Any idea how much current a 100watts Class A amplifier will consume.

Vijay
 

AMITNOIDA

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I want to purchase an Isolation transformer and a servo stabiliser for my audio equipments. My audio setup may be BE-718 + Operetta + Nova Peachtree + CDP

What will be the approx. power consumption in case of listening at moderate level? Does audio systems draw more current when listened at high level?

Equipment's maximum load are generally specified. As an example, Operetta maximum load of Operetta power amp is 950 W. Does it mean that whenever, one operates Operetta the power consumption for the amp will be 950 W during the listening period?

Will a 2.5 KVA Servo stabiliser will be sufficient for my setup?

Guys, those have high power audio set-up, how much power bill you pay for playing the audio set-up?

The problem is more as I have already three ACs and three aquariums including one Marine with no. of heaters and a chiller and my power bill is already in the range of 4k per month.
 
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The problem is more as I have already three ACs and three aquariums including one Marine with no. of heaters and a chiller and my power bill is already in the range of 4k per month.
I think you will be a noted guy in World Climate change forums. Did you get any call from UN or Greenpeace?
:eek:
 

AMITNOIDA

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I know a guy in Chennai, who had about 14 aquariums in his Fish room and his power bill used to be around 7-8k per month. Now he has scaled down to 7 aquariums. :D

I think you will be a noted guy in World Climate change forums. Did you get any call from UN or Greenpeace?
:eek:
 

exhilaration157

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Let's clear something up here, Class A does not draw full load all the time. If that were the case it would be quite hot to the touch even at very low volume playback. The following explanation is not complete, but I think it gives the general idea.

To understand a bit about class A vs. class B and class AB you must understand that an amplifier (for example sake) uses an electrical device called a triode (meaning three elements). This can be a tube or a transistor. The input and output of the amplifier are on either end of the circuit and in the middle there is an element in the triode where a voltage is applied. When a small voltage is applied to the input the voltage applied in the internal element amplifies it and sends it to the output. SO... when this amplification happens current flows (voltage x current = power consumption). When no input is given there is still a small amount of current called idle current (aka bias).

In Class A: All the triodes are on at the same time and they amplify both positive and minus portions of the voltage wave. Class A is for small amps that are "single ended" i.e. one triode, and single ended is prone to harmonic distortion. For amps with more than one triode one half of the wave is given to one triode and the other is given to the 2nd triode, making for a distortion free sound. However in class A the triodes are kept on all the time consuming current, so class A is inefficient

In Class B: One triode does the positive side of the wave and the other triode does the negative side of the wave. Each triode is switched off when it's partner is doing the other half. So the triodes are on half the time. This makes for efficiency, but also makes for nasty nasty cross-over distortion at the point the positive and negative sides of the wave join.

In Class AB: the triodes are still switched but they are both powered on for a short time as the wave is passed from one to another. Hense the name class AB push-pull design.

Now for the power consumption question: When an amp uses electrical power (i.e. Watts) it heats up as most of the electricity is dissipated as heat. If your amp was consuming 100 watts at idle, it would be hot like an easy bake oven with light bulb inside. You probably notice that it only heats up when you play loud music for a long time. So even if your amp is using a bit of idle current it is not consuming much power.
 
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