Home Theater Forum and Systems banner

1 - 20 of 25 Posts

·
Registered
Joined
·
14 Posts
Discussion Starter #1 (Edited)
Hi,

I did some research on this, and I can't seem to find a good answer under these circumstances.

I just bought a brand new Pinnacle Subsonic subwoofer, and I'm noticing a hum/buzz from the unit. Even if I unplug all rca connections and keep the volume down it is still present. It seems to be quieter on one different wall outlet (and I've tried all outlets in the apartment). Also, it seems to be louder when I put the sub on its intended shelf.

One more thing, I also bought a small guitar amplifier a couple of months ago. I mention this because I also have the same problem with this amp- there is a low hum/buzz with no inputs plugged in and the volume all the way down, on any outlets in the apartment.

Is it possible the problem lies with the apartment building? It's old, built in 1920.

Any input would be appreciated-

Thanks.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #3
Hi Peter,

The hum is at the same level no matter what I do with the volume. And I believe the hum is coming from the amp.

Honestly, I don't even know what a power conditioner is... might it be a possible solution?
 

·
Premium Member
Joined
·
3,374 Posts
It is not a permenant solution but try a 3 prong to 2 prong adaptor on the subwoofer power chord and see if the hum goes away. That will at least let you now if it is a 60cycle hum from a bad ground or the amp on the sub.
 

·
Premium Member
Joined
·
3,374 Posts
OK Then try a 2 prong to an adaptor with a ground on it.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #8
Thanks for your replies.

I tried a plug adapter with a ground, and it did not help.

So, it looks like trying a power conditioner might be a solution. Any recommendations on one? Maybe any one will do? I looked on Amazon and saw one made by Furman for around $50- The reviews are good.
 

·
Registered
Joined
·
49 Posts
Is the hum emanating from the speaker or the amplifier? If the former, it is probably a ground fault or power supply problem in the amplifier. If the latter, the amplifier transformer is probably the source and could be due to DC on the power line.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #10
Hi rkeman,

I believe the hum is emanating from the amplifier. Could you explain more about what you mean by 'DC on the powerline'?

Thanks.
 

·
Premium Member
Joined
·
5,802 Posts
Hi rkeman,

I believe the hum is emanating from the amplifier. Could you explain more about what you mean by 'DC on the powerline'?

Thanks.
If it is coming from the amp... You can disconnect the inputs, and outputs and it should still make the noise, I believe.
 

·
Registered
Joined
·
14 Posts
Discussion Starter #12
Oh thanks. Yes, that is the case.

So, possibly it could be the amplifier transformer, or the fact that I live in a very old building and have had other hum issues with a guitar amplifier. So, I'm still thinking about the power conditioner solution that a couple of you guys have mentioned. Hopefully that will clear it up... unless anyone else wants to chime in about this issue.

Thank you-
 

·
Registered
Joined
·
49 Posts
Direct current (DC) on a power line can overload (oversaturate) a transformer and cause the coils to vibrate. This results in the hum. If the transformer is loose, poorly damped mechanically, or is wound too loosely a hum may also occur. The latter will not respond well, if at all, to line conditioning. Relatively few power conditioner block DC and the least expensive one that I have experience with is sold by Emotiva. An internet search is sure to yield other possibilities. Good luck!
 

·
Premium Member
Joined
·
3,374 Posts

·
Banned
Joined
·
76 Posts
One thing not mentioned here. You may want to buy a receptacle tester. They cost less than 20$. They have diagnostic LED's and what they mean right on the plug. I found my wall plugs to be wired wrong and some without grounding in my old house.
 

·
Premium Member
Joined
·
5,802 Posts
Oh thanks. Yes, that is the case.

So, possibly it could be the amplifier transformer, or the fact that I live in a very old building and have had other hum issues with a guitar amplifier. So, I'm still thinking about the power conditioner solution that a couple of you guys have mentioned. Hopefully that will clear it up... unless anyone else wants to chime in about this issue.

Thank you-
Any chance you could plug the amp in another outlet to see if it is that outlet causing the problem... Or better yet take it to a friends house and see if you have the same noise?
 

·
Registered
Joined
·
4,017 Posts
One thing not mentioned here. You may want to buy a receptacle tester. They cost less than 20$. They have diagnostic LED's and what they mean right on the plug. I found my wall plugs to be wired wrong and some without grounding in my old house.
Any chance you could plug the amp in another outlet to see if it is that outlet causing the problem... Or better yet take it to a friends house and see if you have the same noise?
+1
And +1
 

·
Banned
Joined
·
76 Posts
I should add its important to test the entire circuit. Your circuit breakers will let you know which plugs are on the same circuit. The plug you are using might be wired right but that doesn't mean the others are right. Plugs without grounds are still polarized snd that wider prong serves as the "ground" electrically. If some receptacles are reversed then the items plugged into them will "ground" into the live connection at the other receptacle. Finally - having all the audio equipment on the same circuit helps. When connecting low level lines, as you do for a sub, if the amps are on different power circuits there is a greater chance of humming and noise as you are effectively creating a bridge between two high power circuits using a thin wire thats carrying just a couple of volts.
 
1 - 20 of 25 Posts
Top