Line Voltage Drops

[oguinn]

Over the past couple years there have been some topics on these forums about how low voltage from the mains can cause funky performance, but I'm having trouble finding the ones I'm looking for. Can anyone tell me what it sounds like when that happens?

The reason I'm trying to find information is because recently something in my system has been creating an extremely intermittent pop. Like once, maybe twice, per listening session. It's been very difficult to troubleshoot because of how infrequently it happens. I've tapped on the topside of every chassis in the chain with no results, although I wouldn't necessarily expect any. I'm trying to avoid working on the Kaiju and BeePre if I can help it because they're unwieldy.

(Not really looking for troubleshooting steps here since I figure it's going basically boil down to me catching it when it happens, figuring out which channel it's coming out of, then removing pieces from the signal path until I narrow it down. Mostly ruling out mains voltage sag and kvetching)

[Paul Birkeland]

Low line level voltage will cause a BeePre 1 to develop hum that wouldn't otherwise be there.  A pop could be other pollution on your mains though, does it happen on both channels?

[oguinn]

I don't know yet, unfortunately. The only times I've heard it happen is when I'm across the room and unable to tell which channel it's coming from.

[oguinn]

Paul, I think I caught it happening. It seems to be in both channels.

[Paul Birkeland]

That would likely point to something going on with the powerline.

[oguinn]

Honestly, I'd prefer that. It's infrequent and I don't feel like chasing cold solder joints forever, so even if it isn't I'll probably let sleeping dogs lie until it's a real problem.

Are there any solutions to shitty power that don't include me ripping the plaster off of 110 year-old walls and running new wire?

Thanks, Paul.

[Paul Birkeland]

It's possible that whatever is causing the problem is some kind of device in your house, and you might be able to swap the feed to that device to the other half of your panel to resolve the issue.

[Doc B.]

Could be something turning on like a burner with an electric start, or a fridge with a funky capacitor. Do you have an oil burning furnace/hot water heat?

[oguinn]

It isn’t immediately apparent what could cause it. It doesn’t seem to be the upstairs furnace, and it doesn’t seem to be the mini fridge in the office. I haven’t noticed a correlation, but who knows. I’d almost bet it does have something to do with the fridge since bringing it into the office is around the time the popping started.

[Paul Birkeland]

It could also be something stopping that's doing it.  I know one of my bathroom fans does some funny things to electronics in another room when it turns off.

[oguinn]

Old thread at this point but wanted to provide a final update.

It was the mini-fridge we moved up here over the Fall. When the compressor kicks on it causes the popping I heard (actually at the power strip, which I’m sure is a great sign).

[EricS]

Glad to heat that you found it!  I was going to suggest running through the house and trying EVERY switch, lamp, etc while someone is listening for your pop.

Around here (central Pennsylvania), they switched our AC mains service to include TWACS (two-way automated communication system) for remote meter reading - this is a major pain.  The carrier wave is about 400Hz and CANNOT be filtered out because it's too close to the primary frequency of 60Hz.  So, every 40-60 mins, a number of my electronics equipment emits a high-frequency "chatter" sound for several seconds.  This chatter noise bled straight through the Class-D amps I used to have (this is why I no longer have them).  I can hear it in all of my equipment, but it no longer comes through my speakers.