Am I correct in saying an amp can not be 1000watts when the power consumption on the back of the device says 250w at 50hz?
I have stereo that's 3500watts and I am running it of an Australian power socket which is 240v 10amp = 2400watts
can it really put out more than it is drawing? or is it totally different thing?
Cheers
I have stereo that's 3500watts and I am running it of an Australian power socket which is 240v 10amp = 2400watts
can it really put out more than it is drawing? or is it totally different thing?
Cheers
It's most likely a PMPO rating (Peak Music Power Output). A completely useless (except for marketing purposes) measure 
RMS rating is what you really need to look for. It is a theoretical figure that the amp can possibly produce on a transient for a split second.
If the consumption figure is 250W then you are probably looking at most 100W per channel RMS and most probably lower.
Tony.
RMS rating is what you really need to look for. It is a theoretical figure that the amp can possibly produce on a transient for a split second.
If the consumption figure is 250W then you are probably looking at most 100W per channel RMS and most probably lower.
Tony.
learn to read the supporting literature.
100W+100W into 8r0+8r0, both channels driven continuously by 1kHz sinewave with a maximum distortion of 0.1% to stand xxx, is completely to unambiguous.
It is also impossible to get more of this output power continuously, than what is put in continuously.
Change the spec to:
127W+127W into 8r0+8r0, 1kHz gated sinewave, 5% duty factor, to standard xyy, is equally valid.
Similarly:
317W+317W into 8r0 peak instantaneous power to standard zyx is quite possible.
The transformer for all these specifications is likely to be somewhere between 200VA and 500VA.
The labeled power rating could be any number the manufacturer cares to put on the device that they think gives guidance to potential users and operators.
100W+100W into 8r0+8r0, both channels driven continuously by 1kHz sinewave with a maximum distortion of 0.1% to stand xxx, is completely to unambiguous.
It is also impossible to get more of this output power continuously, than what is put in continuously.
Change the spec to:
127W+127W into 8r0+8r0, 1kHz gated sinewave, 5% duty factor, to standard xyy, is equally valid.
Similarly:
317W+317W into 8r0 peak instantaneous power to standard zyx is quite possible.
The transformer for all these specifications is likely to be somewhere between 200VA and 500VA.
The labeled power rating could be any number the manufacturer cares to put on the device that they think gives guidance to potential users and operators.
No
Many manufacturers measure the power consumption with 1/8 output power. Then 250w seems reasonable.
If you listen to music and not sine waves, it is no problem to get peaks of 3500w out of your 2400w socket.
This should have read :
RMS rating is what you really need to look for. PMPO is a theoretical figure that the amp can possibly produce on a transient for a split second.
Tony.
i have to amps : arcam delta 290 rated 75w 8ohm (150w 4 ?) and cambridge audio 740C rated 100w 8 / 150 4 ohm , with the same speakers (4 ohm) the arcam plays the same " loudness level " at 1/3 volume while with the cambridge i have to go to 1/2 volume
Yes, a reseacher came out to field to weld strain gauges to a cast iron pipe with only a battery powered "attache case".
The peak power at the spot weld must be enormous to melt the strain gauge and the 18mm thick cast iron at the interface. Yet it was all done at 12V and without a dc to dc converter.
The peak power at the spot weld must be enormous to melt the strain gauge and the 18mm thick cast iron at the interface. Yet it was all done at 12V and without a dc to dc converter.
the position of the volume control has nothing to do with amplifier output voltage/power.
Measure the input and output voltage ratios to find the "gain" at your volume control position for the two amps that sound the same "loudness".
Indeed, but I was thinking of conventional 4R or 8R speakers, so I think you'd need to boost the voltage up somewhat..?
I am not arguing against your example.
I believe your post is completely valid.
I am pointing out that there are other examples of where instantaneous peak power is available from "low power" type supplies. My example simply confirms what you are saying.
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