Help me decide how to eliminate transformer hum

jrlouie

So what do you guys think? I have transformer hum.
http://www.polkaudio.com/forums/showthread.php?t=38893
FYI...I have flipped off all circuit breakers except the one my amp is on, and only having the amp plugged in I still get the hum/buzz.

I have a Tripplite LC1800, but this mostly just does surge and voltage regulation. Not much filtration. I called them to find out exactly. It did not help in any way either. They said they had never heard of having “DC” on your AC lines, which PSAudio states can cause transformer hum.

Anyway, I’m thinking about buying a conditioner (maybe Panamax or Monster) using the 30 day trial period and just see if it eliminates it. The other option is the Humbuster from PSAudio. Do you guys think the conditioner is the best bet? Or maybe the Humbuster (unfortunately PSAudio's trial period does not include free return shipping)?
Do you think a conditioner will remove the hum/buzz?

SuperDave

Sounds like a conditioner would work for this problem. Your flickering lights show that your power is unsteady. If you have an ohm meter and a basic understanding how to use it check the resistance from ground to a copper waterpipe (since you are in an apartment). The resistance should be less than100 ohms (much less I hope). If you are close to the bottom floor you can run some copper wire to earth ground. Check with an electrician if you are unsure what to do. Getting a good ground might be cheaper than getting a line conditioner. Perhaps your maintenance dept could check this. Tell them about your power flucuations.
Another way to t/s the problem would be to take your equipment to another location (a house with a good ground) and see if the hum persists but this would be a pain.
Good luck.

SD

Skynut

Ground everything.

I had a hum and I put ground wires from the chasis of each component to my power conditioner. Now I have no hum.

You need to ground the cable coax also.

try to unhook the cable from the system and see if the hum goes away.

Skynut

When I first got my hum I unhooked all but the basic equipment and still had a hum.
I grounded each component and the hum went away.
So I hooked everything back up including the t.v.
The hum was back.
I unhooked the cable and the hum was gone.
It was comming from the cable through my set and the rca output in the set back to the rcvr.

I grounded the cable coax and the hum was gone again.

jrlouie

I flipped all breakers off in my apartment, except the line my amp is on. I unplugged everything else on this line including the satellite cable (amp only thing plugged in). My amp still had a buzz. Nothing from the speakers, just the amp itself. Also, I live in an apartment complex.
Don't know if those details matter for your suggestions.

Skynut

If it is not comming out the speakers then it might just be the amp.
Is the amp grounded?
You can use a cheater plug to see if it is the ground.
Was anything hooked up to the amp? speakers or the source?

jrlouie

Yeah, I probably should've just summed up that other thread I put a link to. Sorry. Cheater plug doesn't help. I did not disconnect items from the amp itself, although the only things connected could be the 990 and speakers. The 990 was unplugged.
I contacted Outlaw and they suggested it could be low voltage or DC on the AC line. I tried using the amp on my voltage regulator, but that didn't help. So I was leaning towards DC on the AC line. But I don't know.

BlueMDPicker

jrlouie wrote:

My amp still had a buzz. Nothing from the speakers, just the amp itself.

So, you have mechanical hum?

Make sure the transformer is snuggly mounted (no loose bolts/nuts) to the amp chassis.

Try setting the amp on another surface. I have an old tube amp that has a deafening transformer hum (mechanical) if placed on anything less than a perfectly flat surface.

jrlouie

Seems like if there were loose nuts/bolts, it would do it all the time. In my scenario, it tends to be more noise during the evenings. Sometimes it is dead quiet. But definitely something to consider I guess if I have a little free time to pop off the cover.

Tour2ma

First if your amp has a 3-prong plug on your amp, I do not beleive that flipping breakers would have any impact.

Second, many transformers hum... some louder than others, but many hum.

Tour2ma

Added thoughts...

If the humming is audible over music at your normal listening levels, call your amp Manufacturer's CS.

RuSsMan's Radii's hummed noticeably. I think he reported that when he upgraded power cords that the hum dropped significantly.

ohskigod

my carver has a little hum, actually alot of carver's I heard had a little hum, nothing too nuts though

jrlouie

Tour2ma wrote:

If the humming is audible over music at your normal listening levels, call your amp Manufacturer's CS.

I would say that it is mostly not audible when I listen to music. But, when watching a movie and during quiet passages, say when two people are having a quiet conversation, I can hear it. I have called Outlaw CS and we've been doing a little testing. Every test so far has not uncovered anything and it seems it is their experience that this transformer hum can be from low voltage or DC dirtying up an AC line. I have a voltage regulator so I would think low voltage isn't the issue, but I'm no electrician

I'm not exactly sure what "a little hum" means to everyone. I guess that can be subjective. I'll put it this way...although fairly faint, I can hear it sitting on the couch about 10 feet away during low level dialogue like a quiet conversation in a movie (or whispering). Any more sound from the movie or if I'm listening to music, will drown it out. It is faint enough that my girlfriend says she doesn't even notice it. But I do.

Tour2ma

Once you know it's there, you'll always hear it.

Hope a PC helps you...