So this morning when I powered on my monitors (speakers) they produced a loud continuous buzz regardless of what level I set the volume.

Any audiophiles out there have an idea of what is going on?

I kind of need these suckers and I can't really spring for the ~$100 to replace them.

9/29/2010 12:36:36 PM

Outlet's not properly grounded, maybe? Plug them into a different outlet, see if they still buzz.

9/29/2010 12:37:28 PM

gave that a shot but no dice

this is more than just a hum
it is a very loud buzz

and I'm not getting playback at all from the speakers

9/29/2010 12:46:10 PM

Loose cable, phase switch in wrong position?

9/29/2010 12:50:41 PM

I checked my signal chain and it all seemed right

the speakers produce the buzz even without any signal being sent to them - and with the inputs unplugged!

I even took the left speaker (the one that houses the inputs, etc) to another outlet and plugged it up alone and it makes the loud noise

the noise is produced with the volume knob turned all the way down and turning the knob only produces some mild distortion in the signal - it doesn't alter the intensity of the sound in any way

9/29/2010 12:58:35 PM

Maybe you have a punctured cone.

9/29/2010 12:59:18 PM

the loud buzz is transmitted across BOTH speakers, however

I popped them open to sniff around for burned out electronics and to look for corrosion but I didn't really find anything

I'd be willing to pay an EE or somebody to fix these things!

9/29/2010 1:19:12 PM

further investigation!

so I fear that I might be the victim of the capacitor plague
I've got two bulging capacitors with a little bit of electrolyte on top

who on Tdub can replace capacitors?

9/29/2010 1:57:49 PM

definitely an internal problem--id say you've found the culprit. hopefully a soldering iron and some new caps will save you some dough.

9/29/2010 2:12:38 PM

okay I'm now looking for someone who is handy with an iron
my soldering is sloppy and I'm not confident with it
also it looks like these caps are epoxied on (I guess you break them free with a heat gun?)

I know someone on here has to be damn good at this - didn't y'all go to school for it?
a little help sourcing these capacitors would be nice too but I can find them on my own if need be

I'd just like a quote from someone who wants to make a couple bucks doing something simple

9/29/2010 2:18:22 PM

some pics of the capacitors

9/29/2010 3:51:15 PM

paging fregac

9/29/2010 5:42:23 PM

yeah I sent him a PM already

9/29/2010 5:59:09 PM

I need two 4700 uF capacitors (electrolytic)

the power source outputs 14V (x2) @ 8A

found 'em on DigiKey

they come in a 16V and 35V version
suggestions as to which I should go with?

[Edited on September 29, 2010 at 6:33 PM. Reason : ?]

9/29/2010 6:29:04 PM

The 35v. But, you should be able to see on the caps on the board what they are rated for.

9/29/2010 6:44:54 PM

is there a reason the 35V is preferred?

there are two capacitors

is it safe to assume that the power source puts out two 14V rails running independently to the caps?


I took the speakers apart further and confirmed that the caps are 35V

[Edited on September 29, 2010 at 8:04 PM. Reason : ]

9/29/2010 7:46:34 PM

THANKS FOR EVERYTHING, TECH TALK

you guys rule!

9/29/2010 10:16:26 PM

2v really isn't enough margin of safety. On power up I wouldn't be surprised if those rails rise above 14v for a brief period of time.

Be absolutely certain you get the polarity right when you replace them. On the positive rail you'll have the ground terminal of the cap to ground, on the negative rail you'll have the positive terminal to ground.

[Edited on September 29, 2010 at 10:34 PM. Reason : .]

9/29/2010 10:33:45 PM

With filtering caps you always want them to be rated well above the voltage you will be dealing with. 10v or more above, usually. Most caps for a 12v rail will be rated for 25 or 35v.

Also, you'll need proper Low ESR caps. Something from Radio Shack won't cut it, they'll just die again.

9/29/2010 10:57:41 PM

I have an electronics degree from EZU and I say that you just have something plugged into the wrong port.

bwhahahahahahahaha epic rips coming

hahahahaha have no mercy, shred hard, i can take it

9/30/2010 1:15:02 AM

I have a MA in reading books and plugging shit up from a pinko school in NYC

which means I double checked plugging things up right and then I read about it
and then I checked it again

I have a good understanding of the signal chain in my audio system and I troubleshooted (? - troubleshat?) the problem to two bulging caps squirting electrolyte juice all over the place

no one is going to rip on you
thanks for playing

10/1/2010 4:22:29 AM

I replaced the capacitors and the speakers are working!

I took some pictures and video. I'll edit it together into an instructable or something.

10/10/2010 9:48:29 PM