Re: Dummy loads for amplifier fault finding
nice
nice
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Re: Dummy loads for amplifier fault finding
It's interesting to do some math.
With 1,000W (total) input you have around 35 minutes before the oil heats to 100°C, in a 20L barrel. So 2x500W as well. Water is much better at 105 minutes.
Very few, if any, audio amplifiers are designed to output full power as a sine-wave for long periods of time. It simply costs too much to size heatsinks, power transformers etc for that. Many are not rated for all channels driven, just a single channel.
My old (fanless) home-made gear can do it, but that is a DIY norm for audio power amps.
I hate parties where the crappy cheapy A/V receiver overheats and cuts out or blows up after 1/2 hour. Buzz kill!
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Re: Dummy loads for amplifier fault finding
water expands and contracts - not good in a can!
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Re: Dummy loads for amplifier fault finding
Yeah thought about distilled water when putting it together (which is pretty cheap) but got offered the oil free & it gives plenty time ... easy to build in thermometer or pressure releases too but I've never bothered ..
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Re: Dummy loads for amplifier fault finding
I think the water volume goes up around 4% from 20-100°C so 20L becomes 20.8L... time for an expansion tank lol. I wonder how those oil-filled electric radiant heaters handle it.
Otherwise it's cooling fans I guess, on larger resistors not immersion heating elements.Comment
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Re: Dummy loads for amplifier fault finding
5mins @ 6kW is plenty of time for a barrage of tests ...
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I have here a Magnum IA.100 which belongs to my parents.
The unit powers on & when the relay kicks in, you get a pop from the speakers (this might sound weird but is usual behavior for this amp). However, you get nothing coming through it from any of the inputs & no pops and crackls from any of the controls.
Because of the sound from the speaker when the amp turns on I have assumed that the output section probably works but I could be wrong & I'm not sure how to test that side of things further.
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Hi, people.
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