Help with hum caused by amplifier

[SocialCircle]

I have an ATI amp driving my front speakers. You can hear a hum coming from the speakers when the amp is driving them. There is no hum when I had my Denon receiver driving them. At regular and high volume levels the hum is not very noticeable. However, during quiet periods of movies or music or at low volume levels, then the hum is bothersome to me. Any suggestions on how to eliminate this?

[Geoffcin]

I have an ATI amp driving my front speakers. You can hear a hum coming from the speakers when the amp is driving them. There is no hum when I had my Denon receiver driving them. At regular and high volume levels the hum is not very noticeable. However, during quiet periods of movies or music or at low volume levels, then the hum is bothersome to me. Any suggestions on how to eliminate this?

The first thing you want to try is a "cheater" plug. This will often cure a ground loop. You may also want to try it on your source which may be the cause even though you didn't have a problem with your receiver.

[SocialCircle]

What is a cheater plug?

[Geoffcin]

A cheater plug has a three prong receptical in and a two prong termination out. It allows you to bypass the ground prong.

[SocialCircle]

I purchased a Panamax line conditioner/ protector that keeps the components isolated. This took all of the hum out of my center and left front speaker. The right front has a slight hum that I can live with now with and without the cheater plug. So I' m happy now. I do not notice the hum in the right front speaker unless I get right up next to it. I guess there is some small situation with channel 5 and/or 6 on my ATI 1506....as those are the two channels I have bridged to drive my front right speaker.

Thanks.

[mlsstl]

Hum can be caused by a lot of different things.

Since you still have some slight hum in the right channel, try trading the left and right input source cables to the amp. If the hum changes from the right to the left, you next might try a different cable. You might have one with inadequate shielding or a poor internal connection.

Try turning nearby components off and see if the hum disappears. If that is the case, repositioning your equipment may help. It would also be useful to know if the hum is present with all input sources (CD, phono, tuner, etc.) or just one of them.

Trying to narrow things in that manner can help you solve the problem.

[SocialCircle]

I took the old speaker wire off and put new speaker wire running from my amp to my right front speaker and no change.

The hum only occurs when I turn my amp on....so I still believe it to be a small situation with channels 5 and/or 6 with my ATI amp. The hum is very slight now and it does not bother me.

The long term cure is going to be to upgrade my Denon 4300 to a separate processor and/or a more recent Denon A/V receiver and purchase a 3 channel amp. I can let my ATI 1506 drive my two main fronts by bridging channels 1 and 2 and then 3 and 4. Then my 3 channel amp can drive my center and my two surrounds.

I'll gain better bass management by being able to set my exact crossovers with all speakers and I'll get rid of the slight hum by not using channels 5 and 6 of my ATI amp.

[mlsstl]

Hum is fairly unlikely to come from speaker wires. It is a relatively rare cause.

I was talking about switching the input source cables. Normally these are pairs of RCA plug cables that run from your CD player or tuner to the amp.

However, you indicate it doesn't bother you now so it may not be worth your time to investigate any further.

[SocialCircle]

I misunderstood. I may try that as I have some other cables I can try.

[Robert-The-Rambler]

I have an ATI amp driving my front speakers. You can hear a hum coming from the speakers when the amp is driving them. There is no hum when I had my Denon receiver driving them. At regular and high volume levels the hum is not very noticeable. However, during quiet periods of movies or music or at low volume levels, then the hum is bothersome to me. Any suggestions on how to eliminate this?

If you are connecting the external amp to a receiver then connect a RCA ground loop isolator to the pre outs between the receiver and the amplifier.

Here is the link from Radio Shack.

http://www.radioshack.com/product/index.jsp?productId=2062214

They work really well and really saved me from audio disaster when I went the separate amp route years ago. For $17 it is worth a try. Good luck.

[Luvin Da Blues]

If you are connecting the external amp to a receiver then connect a RCA ground loop isolator to the pre outs between the receiver and the amplifier.

Here is the link from Radio Shack.

http://www.radioshack.com/product/index.jsp?productId=2062214

They work really well and really saved me from audio disaster when I went the separate amp route years ago. For $17 it is worth a try. Good luck.

I've always wondered if these degrade the signal in any way?

[Robert-The-Rambler]

But it is way better than dealing with the hum. For my application the hum was so bad that I couldn't do much of a comparison.