Hum in the system


Hi, I just installed a MSB Link DAC III in my system and that promptly caused a low but audible hum. The hum goes away as soon as I turn off my power amp. (but that's not exactly a workable solution....) Now, both the power amp (Acurus A-100) and the MSB have 3-pronged plugs, so I wonder if there is a ground loop problem. My question is, how do I fix it? The Mondial M.A.G.I.C won't work, because it is a cable ground isolator - at any rate I don't have cable TV. Any suggestions/solutions will be much appreciated. Thanks!
Ag insider logo xs@2xsrama
My system, a Naim CD3 CD player, Denon DVD player and some other high end brand FM tuner hooked up to an Angstrom 200 preamp and Tandberg amplifier, running out to a pair of Bag End TA-15 professional speakers, created a slight hum (definitely noticeable) before I got cable TV. When I got cable, the hum increased somewhat. I tried swapping out the interconnects with other interconnects between the amplifier and the preamp, but had no real change in hum. Is there something that I can use to decrease the hum? Thanks! JuanCAyllon@yahoo.com
I'm currently having a bit of a hum problem myself. I was originally using a Denon 2700 receiver to power my speakers but after adding a proceed amp2 the speakers started humming. Would using the balanced inputs on the amp help the problem at all?
You can buy a cheater plug from any hardware store - it is essentially a 2-prong plug, with a 3-prong socket on the other end into which you can plug your component's 3-prong plug. It is NOT intended as a device to drop the ground - it has a little metallic tab that you are supposed to screw into the wall plate - of course, if you do that, you will not have dropped the ground so people tend to bend the tab back, away from the wall plate and thus effectively drop the ground. Hum caused by hooking up a TV or VCR to your amp or receiver is cause because the cable is grounded separately from your power line - this causes a ground loop hum. In order to get rid of this hum, you have to isolate the cable ground - the safest way to do this is to buy Mondial's MAGIC box - which stands for Mondial Antenna Ground Isolation Circuit. Essentially, you connect it to the cable outlet in the wall and then run another cable from the Box to your TV or VCR as the case may be. This will get rid of the Ground loop caused by Cable TV, guaranteed. Note, that the Magic Box only has inputs and outputs that accept the standard coaxial TV cable - it can only isolate hums caused by cable tv - NOTHING ELSE - as some people seem to mistakenly believe.
I just thought I'd update what ended up happening with Shiv's DAC hum. We first dropped the ground, which worked for about a day. After being left on all night without the ground, the entire DAC died. I suspected power supply (wall wart) problems, though MSB denied the likelyhood of this. Shiv's wall wart was cold to the touch, and normally they are slightly warm whenever left plugged in. MSB wanted the whole DAC sent back, but I talked them into starting with just sending another power supply--I didn't want a customer who just purchased a new DAC to have about two weeks of downtime if it wasn't nessasary. It did end up being the power supply, and the DAC has worked just fine every since the wall wart replacement. Dealers as well as customers take note...if you even encounter the problems like at the start of this threat, begin with the power supply after a few other routine checks such as interconnects running near power cords, etc. Jeff