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.
What Ive done........01-01-2025, 01:26 PM -
- Prior owner tried a replacement main board. No difference.
- Samsung 2x red blinking standby LED = panel fault
- Jumpered FB_TRDY_1 (pin 1 CN1300 left. main tcon->left side buffer boards) and FB_TRDY_3 (pin 95 CN1301 right. main tcon->right side buffer boards) This allows testing individual T-Con (on main board) connection to panel on this Samsung. Found fault on left side (viewing from rear of TV)
- Each side has 2 buffer boards, disconnected left side flex between 2 buffer boards. Fault is on the left most board.
- Tape masking eventually isolated to CN1300 pin 15 (CKV4_GOA) Display
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I have been having a fun time at work with two pieces of equipment that had shorted components or shorted component cables to machine frame
I would check what my multi meter was telling me about how many ohms I getting with the multi meter was telling versus the ESR was telling me about weather or not it really was a short to machine ground or not
One note at first we thought that it might be a bad I/O card or a malfunction PLC including me as well but I thought I would try and see if removing the I/O cables would make a difference or not and this time it did make a difference... -
My childhood best friend was killed about 9 years ago. His parents are finally letting go of his things, and they offered me his Polk RTi100 tower speakers. The Polk RTi100 towers are one of a handful of designs from the early 2000s that is a full range 3-way tower with a built-in self-powered subwoofer. This is accomplished with a plate amp integrated into the speaker input panel.
I think they used them for a while, but they've been sitting for at least a few years now. After about 40 hours of driving to their house and back (both they and I have moved in the last 9 years) I got... -
Hi, people.
I've got an amplifier assembly from Mackie CR4 parts. It's just an amplifier, there was no speaker housing, so I used my set of CR4s to test it.
Anyway, upon connecting everything and hooking the "new" amplifier to an audio source, the sound played clearly and strongly for the first ten seconds. I was happy it was working. Then the sound started to fade out during the playback until it was no more. After it had "dropped to zero", there were two very short intervals of sound playing at the normal volume, as if the amplifier was trying to...
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