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!
srama
First try a cheater plug. Place on one component at a time and see what happens. Let me know the results and we'll then go to the next step.
I had a crackle in my system after I added a Rotel DAC and I finally narrowed it down to the digital interconnect. Some brands may not be compatible with all players or it may be defective. I put in a different brand cable and it fixed it right away. Also, check to be sure your cables are not in a "birds-nest" behind your cabinet. Piles of cables not run cleanly and neatly can lead to noise in more complex systems. But try the first posts recommendation first because it is most common fix (using non-grounded cheater plug).
If have cable box connect with TV & DVD. You need to but a MagicBox.($100 for cable box) I had same problem before. (only on some amp) E-mail me if need more info. tlc@gus.net
I HAD THE SAME PROBLEM LAST WEEK WHEN I ADDED SOME COMPONENTS TO MY SYSTEM. 9 OUT OF 10 TIMES, IT'S THE VIDEO THAT CAUSE THAT GROUND LOOP SOUND. FLOATING THE GROUND IS A EASIEST WAY, BUT NOT RECOMMENDED FOR HIGH CURRENT AMP. COULD CAUSE FIRE! THE MAGIC BOX IS THE BEST WAY TO GO. IT'S THE ONLY ONE THAT WORKS. $100 FROM MONDIAL. GOOD LUCK, ANDY
I had the same hum problem , i called Carol Nelson at MSB and Carol swaped a new dac with the problem dac and it fixed the hum problem . Carol is a very nice person and MSB stands behind their products . 650-747-0400 hope this helps .
Thanks for all your responses. I was on the phone with MSB tech support and their suggestion (after we had tried a couple of other things) was to use a cheater plug. That worked.
A quick follow-up. It turned out that the hum was caused by a faulty power supply. MSB sent me a new power supply and voila!, no hum. I don't need to use the cheater plug any longer, which I am really glad about. Again, thanks for the suggestions.
Magic Box for $100? Uh, no. Xantec makes a version of this for $8. brian@hellohifi.com
What is a cheater plug and where do I get one? Please let me know! Thanks...
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
I get hum in my system when my Naim 3.5 cd player is plugged into the wall and the system contains and MFA Magus pre-amp. If I unplug the Naim, the hum is gone. If I replace the Magus with and Audible Illusions L1 pre-amp, there is not a hum problem with the Naim. If I replace the Naim with a Rega Planet, there is no hum with the Magus in my system. So, each piece of gear works correctly and without hum, and there is only a problem when the Naim 3.5 and Magus are in the system at the same time - but, this is my favorite combination, so I want to fix it, any insights?
Had this problem for long.Solved by a really bright guy Arnie Nudell AKA Genesis Tech.I have Three inputs into my KBA A+V Standard(KBA)=Krell Boat Anchor DVD/CD(coax)SAT(Toslink)VCR(composite analog)He said turnoff and unplug imputs.I unpluged VCR and no hum.I had tried everything.
Had this problem for long.Solved by a really bright guy Arnie Nudell AKA Genesis Tech.I have Three inputs into my KBA A+V Standard(KBA)=Krell Boat Anchor DVD/CD(coax)SAT(Toslink)VCR(composite analog)He said turnoff and unplug imputs.I unpluged VCR and no hum.I had tried everything.Ihad tried it all.Krell Tech said cheater plugs Mac Tech said file plug on my 7106 and reverse polarity Dealer said ground chassis together.All said turn off inputs but turning them off does not affect ground loop.GOOD LUCK