Fridge makes amp "pop"

LennyPenny · #1 09-24-2011, 05:26 AM

Hi,

First off, yes I did do a search before posting this, but when looking for "fridge", all I found had to with 810 cabs...

The problem is that, when my fridge kicks in, my amp (GK MB112) pops/snaps/whatever you want to call it. This only happens when I have my ATK700 plugged in (with the amp turned on), not with my P-bass.

Side note: I'm not sure if the ATK is an active of passive bass. The previous owner says it's active, and it does have a 3 band EQ, but on the internet I read that the pickups are passive and only the EQ is active. Can anyone please confirm one or the other? I always plug it in the active input but it's a lot quieter than my P-bass. This doesn't affect whether or not the amp pops, though.

Any suggestions on how to prevent this?

Thanks!

cashpoor51 · #2 09-24-2011, 05:39 AM

you may want to have an electrician look at you electrical system
there could be problems in the system
if the popping gets loud enough you could blow a driver at high volume

WingKL · #3 09-24-2011, 06:03 AM

If this only happens when you have the ATK plugged in then it means that the ATK is picking up whatever interference/spike your fridge is putting out when it kicks on. Is it a really old fridge? Possible solutions are modifying your ATK to include more shielding if the pickup and control cavities are not shielded, using a better shielded instrument cable, making sure the ATK pickups are actually operating in a humbucking mode. Temporarily rewiring the ATK for passive operation to see if it's the preamp that's causing the problem. Lastly you could replace the fridge if it's really old as that would probably save you energy and fix the interference problem.

Vincent P · #4 09-24-2011, 06:06 AM

LennyPenny · #5 09-24-2011, 06:48 AM

Only just noticed that it occurs with the P as well, sorry...
I'm a student and rent a room in the city where I study, and my landlady probably won't get me new fridge just because of my problems with a bass amp. She'd most likely kick me out if she knew how loud I play at times, but there are other musicians in the building and it's sort of an unspoken rule that we won't grass on each other for playing too loud

My landlady is a real cheapskate, she's been messing with energy bills and such. My old fridge broke (for which she blamed me...) and the replacements are kept in a warehouse somewhere, so it's most definitely not a high end model.

I guess there's not much to solve, my room is too small to try to move the amp out of range, if that's even possible. I don't play at execively loud volume at home, just over 9:00 tops, but I'm still worried about damaging the amp.

Could someone please answer my second question as well: does the ATK go in passive or active input?

RickenBoogie · #6 09-24-2011, 07:14 AM

The active input on an amp can be misleading. You should always use the passive input, unless the signal from your bass is just too hot, and if you have a gain control, that works just as well.

LennyPenny · #7 09-24-2011, 07:19 AM

Quote:

Originally Posted by RickenBoogie

The active input on an amp can be misleading. You should always use the passive input, unless the signal from your bass is just too hot, and if you have a gain control, that works just as well.

Thanks for clearing that up!

runmikeyrun · #8 09-24-2011, 09:09 AM

the outlet you're plugging into must be tied to the fridge's outlet. Try a different outlet somewhere else in your place.

Savage_Dreams · #9 09-24-2011, 09:15 AM

Quote:

Originally Posted by runmikeyrun

the outlet you're plugging into must be tied to the fridge's outlet. Try a different outlet somewhere else in your place.

thats what i was thinking too. if your on the same circuit as the fridge that could be the prob.

Spectrum · #10 09-24-2011, 09:27 AM

Also, turn the fridge control up, or unplug it, before playing so it won't kick on. Just don't forget to turn it back down or plug it back in when you're done or your beer will skunk.

ETA: Your milk will also go bad, if you're the kind of guy who drinks milk...

LennyPenny · #11 09-24-2011, 11:45 AM

Quote:

Originally Posted by Spectrum

Also, turn the fridge control up, or unplug it, before playing so it won't kick on. Just don't forget to turn it back down or plug it back in when you're done or your beer will skunk.

ETA: Your milk will also go bad, if you're the kind of guy who drinks milk...

No beer for me, or any alcohol for that matter, and yes, I do drink (soy) milk

Thanks for the suggestions, I'll try another outlet, otherwise it'll have to, and I'll unplug the fridge if I need to play louder than usual.

seanm · #12 09-24-2011, 12:43 PM

You could try getting a UPS and plugging the amp into that. The UPS should suppress the spike as the fridge goes on.

craig.p · #13 09-24-2011, 01:30 PM

I had a similar situation about 20 years ago that I tracked down to heat tape on an outside pipe. The heat tape's little thermal switch was throwing nasty transients onto ALL the house wiring. Not just that breaker, and not even just that phase -- BOTH phases, all outlets. A spike/surge suppressor didn't help. I got rid of the tape and went to a different style that has no switch. But the one thing I didn't try was plugging the heat tape (the source of the noise) into a suppressor, to trap the noise at its source. This might be worth a shot with this refrigerator problem. And a side note: you'll probably get best results with something better than some cheap pos you get at Staples for the same price as a happy meal. A good Corcom from their general-purpose RFI filter line would qualify as "getting serious" but you'd have to mount it in a Bud box and run lines (or chassis connectors) for in and out.

LennyPenny · #14 09-25-2011, 04:41 AM

Another thing to bare in mind: this never happened with my 30W Roland cube guitar amp. Maybe because of the difference in power..?
I don't know what a UPS is, and I didn't understand a thing of what Craig just said... English isn't my native language.

craig.p · #15 09-25-2011, 05:56 AM

Sorry, Lenny. Basically what I was suggesting was to try putting a HIGH quality suppressor on the noise SOURCE, i.e. the refrigerator.

You should also check ground (earth) continuity from amp to outlet. You might have a defective power cord. You'll need to open the amp so you can access it with an ohmmeter. If you don't know what I'm talking about, find someone you know who can help.

Also the building wiring might be substandard. Old or corroded or loose or ??? Can you borrow an outlet checker from someone? Or buy one? They're small, plug into the outlet, and give you indicator readings for reversed polarity, ground lift, and so on. Check both the amp outlet and the refrigerator outlet.

sedan_dad · #16 09-25-2011, 08:04 AM

What are you doing playing in the kitchen?

Spectrum · #17 09-25-2011, 08:09 AM

Quote:

Originally Posted by LennyPenny

Another thing to bare in mind: this never happened with my 30W Roland cube guitar amp. Maybe because of the difference in power..?
I don't know what a UPS is, and I didn't understand a thing of what Craig just said... English isn't my native language.

A UPS is an "uninterruptible power supply", used to protect computers from power outages, and may also smooth out some of the noise in the line.

LennyPenny · #18 09-25-2011, 09:13 AM

Quote:

Originally Posted by sedan_dad

What are you doing playing in the kitchen?

It's a (relatively big) dorm room.

Tried another outlet and no pop! Will check at louder volume later today.

LennyPenny · #19 09-25-2011, 10:55 AM

Played at normal volume (same as with the first outlet) and still pop...
I reckon it's the building's wiring, seeing as how the landlord is always cutting corners.

dmusic148 · #20 09-25-2011, 11:11 AM

Does it happen when the bass is unplugged, but the amp is on? Your first post says no, probably. In this case it is NOT a wiring problem or any other such nonsense, it's airborne noise that your bass's electronics pick up. When the relay in the fridge trips ON, there is a large arc(spark) at the relay contacts, which broadcasts itself over the air, like a radio broadcast. There is a way to prevent this, by modifying the fridge, but there's no way we're getting into that here.