Axiom Home Page Forums General Discussion Home Theater power conditioners

my friends, i get a hum from my ADCOM amp if i dont use a cheater plug. i was thinking about getting one of these, see link below.

http://catalog.belkin.com/PureAV_detail.process?Product_Id=178415

it sells for 350$ but i can get for 250$ from an authorized dealer. the specs seem better than the Monster units and it's 100$ less, what do yo think.

URL police Can't comment on the PureAV as I don't own one yet, but have been looking at them recently. There are many reviews on the net that say these things do exactly what they state, however, there are a few folks on this forum that will tell you it is all hype

http://catalog.belkin.com/PureAV_detail.process?Product_Id=178415

I have seen the PURE at BB but as stated above the reviews are a mixed bag. APC is coming out with 2 models for AV that I have been looking at including battery backup.

I would first try to find the source of the problem.Then if you still want a conditioner then I say go for it.

Hi 500,

You have a "ground loop", one of the most common ills affecting audio and A/V systems, and the power conditioner would be largely (or entirely) a waste of money and may not help. There is no need to "condition" the power for your Adcom amp. It already has a power supply with filters, transformers, etc. and no further filtering is normally required.

First, remove the cheater and use the regular Adcom plug. Now, look at all your connected components (preamp, turntable, video gear, CD player etc.). With the power OFF, reverse the AC plugs one by one of any other components that have a standard 2-prong plug that isn't polarized (one prong is wider than the other, so you can only insert it one way). Each time you reverse a plug, turn on the system with the attached component and your Adcom and see if the hum disappears. In most cases, reversing one or more plugs will eliminate the hum.

If you have a turntable with a separate ground wire, try removing the ground wire from the preamp (if you're using a separate ground). If not, connect the ground wire to the preamp or your Adcom and see if the hum disappears. Likewise, if you are using a powered subwoofer, try reversing the AC plug on the sub and see if the hum disappears on the Adcom. Anything connected to your system with an electrical link is suspect.

If you have any cable feed from a satellite or local cable system remove that, and see if the hum goes away. Often, it does. You may have to insert two cheap balun transformers end to end to "lift" the ground from the cable system, which may be faulty.

Try these fixes before you spend any money on a power conditioner. Keep at it, until you find the source of the hum.

Regards,

Wow! I didn't know why, but this solution fixed my hum as well. Turns out a have a video amplifier for my OTA HD and reversing the plug was the trick.

Alan. Thanks for the lesson.

That's why Alan gets paid the BIG bucks my friend. To help out guys like you and me.

Jay, a Alan pointed out in his excellent reply, the fact that the "cheater" plug worked shows that you have a ground loop. This is caused by there being more than one path to ground in your equipment rather than the desirable single point ground and has nothing to do with the "condition" of the power coming from the outlets. There are safer ways than using the cheater to stop the hum, but they don't require replacing a $1 item with a $250 one. Just to touch on perhaps the most likely cause, if you find that disconnecting a cable TV feed also stops the hum, you can use the item Alan mentioned, such as this one.

what do you mean by "reverse the AC plugs one by one" . do you mean change outlets. i currantly have all my gear plugged into a surge protector. also, the hum only appears once the ADCOM has been running for 20 min or so.

The AC plugs have a wide and a narrow blade. Most outlets will accept the plug with the wide blade on either side. Try unplugging, then rotating the plug 180 degrees, then plugging back in again.

Alternatively (if your outlets don't cooperate) disconnect the input signals (satellite, cable box etc..) one at a time to see when the hum goes away.

If you still get hum when only the amp and speakers are plugged in and hooked up that's probably something different, but usually grounding seems to be the issue.