Operating power requirements?

[Thompsonuxb]

How important is it when choosing an amp.

i.e an amp with 500watts operating power v an amp with 350watts.

How significant is this figure against the output power - is it efficiency related.

Or an intrinsic part of how well an amp delivers its sound?.

 

[expat_mike]

Probably has to be considered in conjunction with where you want to locate the amp.

If your amp is consuming 500watts of electricity, but only delivering 100watts of this to the speakers, then the missing 400watts is converted internally into waste heat by the amp. The greater the amount of waste heat, the more attention that you have to pay, to ensuring that the amp is located where there is an adequate flow of cooling air.

 

[Al ears]

Probably has to be considered in conjunction with where you want to locate the amp.

If your amp is consuming 500watts of electricity, but only delivering 100watts of this to the speakers, then the missing 400watts is converted internally into waste heat by the amp. The greater the amount of waste heat, the more attention that you have to pay, to ensuring that the amp is located where there is an adequate flow of cooling air.

Unless it's class G monoblocks that is.

 

[Thompsonuxb]

You think?

I was just comparing

My Rotel Ra-1520 measures 60watts p/c to 300watts. Compared to the Arcam FMJ19 50watts p/c for 350watts

The next class up the operating power ramps up into the 500watt category for a 10 to 20 watts p/c increase.

Is it about efficiency?

 

[expat_mike]

Unless it's class G monoblocks that is.

The second law of thermodynamics applies to all amplifier topologies.

 

[davedotco]

You think?

I was just comparing

My Rotel Ra-1520 measures 60watts p/c to 300watts. Compared to the Arcam FMJ19 50watts p/c for 350watts

The next class up the operating power ramps up into the 500watt category for a 10 to 20 watts p/c increase.

Is it about efficiency?

Different types of power supply have different levels of efficiency, ie some amplifiers have more of the input power usable to the actual amplifier section than others, Switched mode power supplies tend to be much more efficient than conventional supplies with toroidal or R core transformers.

However assuming the power supplies we are comparing are of the same 'type', most amplifiers use regular toriods or R core transformers and the usual electrolytic storage capacitors, then the bigger the power supply for a given output power rating, the better.

The bigger supply allows the amplifier to deliver greater current for the same (measured) output spec, so greater capability into lower impedances or otherwise difficult loads.

 

[Thompsonuxb]

There is a conflict then more power for better current delivery or inefficient amps.

Going through the reviews section the specs on a few amps on this site make for interesting reading.

 

[AilisRiess]

If your amp is consuming 500watts of electricity, but only delivering 100watts of this to the speakers, then the missing 400watts is converted internally into waste heat by the amp. The greater the amount of waste heat, the more attention that you have to pay, to ensuring that the amp is located where there is an adequate flow of cooling air.

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