The Smell of Hot Electronics

karl · 4442

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Offline karl

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on: January 26, 2011, 09:30:32 AM
If I place my nose within a foot of the vent and directly over it, I can smell what I would describe as "hot electronics." I am assuming the smell is coming from the sandbar resistors, which are directly beneath the vent. It is not a strong smell.

Should I be concerned?

Everything else appears to be fine.

Regards,

Karl


Offline Grainger49

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Reply #1 on: January 26, 2011, 09:36:24 AM
If your voltage measurements were good I wouldn't worry.  That is a dynamic test and if you were within 15% that is to be expected.  As the unit warms up finger oil and other things on the components that heat up will burn off then be gone.


Offline karl

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Reply #2 on: January 26, 2011, 11:03:30 AM
I understand what you mean, but this happens every time I switch it on. It is definitely not a burning smell. I wonder whether I am smelling the hot insulation of the two wires that run directly under the vent and above the sandbar resistors (looking down into the vent). Could the sandbars be heating the insulation?

Regards,

Karl


Offline hasafraker

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Reply #3 on: January 26, 2011, 12:12:23 PM
I would second Grainger's comments here, my Crack smelled for a week after I finished it... (that never gets old LOL) After the resisters burn in you won't notice it anymore. I fire mine up now and don't notice any difference at all. I ran it in for 10 days straight initially. I would assume it will work itself out on it's own with a little time.

as long as it sounds good, who cares?

Main system; AT-LP120-USB Turntable w/AT440MLa, Bottlehead Reduction Phono, Decware ZSP1 Preamp, Pass Labs ACA Monoblocks, PSB Alpha B1's, MartinLogan Dynamo 300 sub. Bottlehead Crack w/Speedball, Interconnects and stands all DIY.

Offline Grainger49

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Reply #4 on: January 26, 2011, 01:28:44 PM
Quote from: karl on January 26, 2011, 11:03:30 AM
I understand what you mean, but this happens every time I switch it on. It is definitely not a burning smell. I wonder whether I am smelling the hot insulation of the two wires that run directly under the vent and above the sandbar resistors (looking down into the vent). Could the sandbars be heating the insulation?

Regards,

Karl

Try running it for a half hour and then turn it off and unplug it.  Allow it to "drain" for a couple of minutes then sniff the underside.  Sounds strange but it might help you find the source of the odor.


Offline dstrimbu

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Reply #5 on: January 27, 2011, 05:15:39 AM
Karl,

Make sure that the wires that run "underneath" the two 3k wirewounds ("underneath" when the chassis is inverted, of course...) are as far from the wirewounds' cases as possible...  I actually lengthened the white B+ lead from 5L to B4 a tiny bit to allow me to position it further from the big resistors... same with the crosstie from 2L to 4L, which I flattened against the bottom of the top plate, and "squared off" a bit to keep its distance...

Finally, I routed the twisted heater wires a bit outside to keep them out of the plane of the wirewounds, but I was also cautious to keep them (they carry 6.3V AC) away from my finely-braided <g> signal leads.

So, minimal "stink" on power-up.  I did rub the cases of the wirewounds with some denatured alcohol before assembly... not sure if this helped, or not.

Cheers,

-don


Offline karl

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Reply #6 on: January 27, 2011, 09:12:37 AM
You have confirmed my suspicions. I think the sandbars are heating the insulation of the wires. I may need to replace the 5L-B4 white wire with a longer one and try to reposition the 2L-4L red link.

Regards,

Karl


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