[mcullinan]

I have all my equipment plugged into a Belkin Power Conditioner. I recently changed my DAC and now get a buzzing from my speakers. When my Superbam (Part of the Merlins, Goes right before amps in chain) is unplugged from the Power Conditioner the buzz disappears.

What is going on and how do I fix it? I tried a 3 prong to 2 prong on the Bam, but that didnt do much. I plugged the Bam straight into the wall. That didnt do anything.
Please help with suggestions.
Mike

[Sonny]

Mike, seems like the problem was introduced when the DAC was plugged into the system.  Have you tried using a cheater plug on the DAC?  So, put the cheater plug on the dac, then plug it into the conditioner.
Hope that works... you know, electrical stuff is strange sometimes...
It could also be a ground loop issue.
Tuan

[mcullinan]

Thanks Sonny, I will try that.
Mike

[TomS]

Mike,

I've never had any noise with my SBAM, so not sure what's happening there.  I agree it sounds like a ground loop.  There are many causes, but sometimes it's caused by a piece of gear that internally ties the third pin of the AC plug to chassis (required for safety) AND to signal ground, interacting with one that does not (some preamps/phono stages).  Some gear, such as my Arcam AVP, even has a "ground lift" switch to break that connection, though most don't.  Doing this with a two to three pin adapter to separate the component from earth ground is ok for brief testing, but really not safe long term (much debated in these parts).  A few questions -

- Does the buzz change up or down with level adjustment?

- Is it still there when you flip the BAM to battery but leave the ac/charger plugged in?

- Have you tried moving the BAM to between the DAC and before the preamp instead of after?  Any change to the noise?

Tom

p.s. - I do love that avatar de jour

[mcullinan]

Tom,
The buzz ceases with the bam on battery IF I unplug the cord. If the cord is still in, it buzzes. I shut off my preamp entirely and the buzz is still there. I took off the audio out cords that go to the Bam from the preamp, still buzzes. The buzz does grow louder if the preamp is on and I turn it up. I am going to try the cheater plug and inverting the polarity by flipping the cheater plug upside down, see if that works.
I think it is a ground loop issue.
Mike

[mcullinan]

Ok its definitely the Bam. I tried the cheater plug right way upside down, maybe something is wrong with the Merlin SuperBam idk...
Any other tips?
Mike

[TomS]

So you still have the lovely Supratek Sauvignon?

What is old DAC and new DAC?

What power conditioner and have you always plugged old DAC and SBAM in there too?

Any new cables, power cords, or cabling changes?

Sorry, just trying to eliminate here...otherwise you probably need to work it through with Mr. Merlin himself.

[mcullinan]

I read in the deep Hemp hum issue that you might have to use multiple cheater plugs. Let me try that see if it helps. The new DAC is the DA100 Signature from Stello. I have purchased new wires but disconnected them and the hum remains.
Cheater Plugs next... Sledge hammer to follow!
Mike

[Mag]

Do you use a turntable, cd player, or both?

[mcullinan]

Neither. Squeezebox 3
Mike