Low buzzing through speaks


Hello All,

 

Need some serious help here. So I just (upgraded?) from a Marantz AV8802A to a McIntosh MX122 preamp. I also just got brand new Revel Performa3 speaks all around (5 channel setup). I disconnect everything from the Marantz and then into the McIntosh, connect the speaks and I have a faint buzzing through all 5 speakers (that was not there previously). I have everything plugged into a Furman Elite 20pfi power conditioner which is plugged into a dedicated 20 amp circuit. My power amp is a Simaudio Titan HT200 5 channel. This is not going through the Furman but directly into the other outlet on the same 20 amp line. I even tried plugging the Sim amp into the Furman to see if that helped-no change faint buzz is still there. I have unplugged just about everything, and the buzz is still there. It is very faint and does not get louder when I turn up the volume. Again it is faint and you have to put your ear up to the speaks to hear but it is definitely there. I have tried so many things and nothing gets rid of it. It is not my cable box (I did have that issue previously with the Marantz but as soon as I unplugged the coax from the box it went away so I just bought a coax loop eliminator connected the cable to that and noise was all gone) as I unplugged that and started there.

 

Any help would be so sincerely appreciated????

kingbr

Showing 9 responses by russ69

@kingbr OK are you ready to solve your problem? I think the high gain of the XLR connection or amp/preamp combo gain is your issue. A 10 db attenuator will kill that.  You might have to use a XLR to RCA adapter to make it work in your application. I'm 99% sure that is what your issue is.

Be sure to read this: A Discussion About Idle Hiss – Upscale Audio

I am going to disconnect XLR’s and try the RCA’s first thing in the AM. Then I’ll try connecting the wire for the ground between the Mac and Sim…

If you have the RCA option, that will be 3db down and might solve your issue, if not see above. 

Wouldn't the XLR 10 db attenuator pad attached to each of my XLR cables work?

Yes, it would. 

BTW, I had this issue with my Mac402 amp. The attenuator did the trick. 

for every -dB of attenuation (5, 10, 20, etc.) that is used, you’ll lose that in volume when playing your system

In almost all cases you'll have plenty of gain to fully drive the amp.

 

I would hope that both would be 0.0V with no audio playing, or the volume turned all the way down.

That is very seldom the case. Volume potentiometers knock down the preamps full power output. Once the gain drops below the audible range there is no need for further attenuation. That is why the idle hiss can be audible, there is still gain being passed through the preamp.

So it would appear switching to RCS’s won’t make any difference, no?

The RCAs will be 3db down from the XLR connections. 3db might be enough to knock down the hiss a bit. 

The old amp did not moan and hum, so I doubt that changing the whole home’s wiring is going to be easier than chucking in the old amp.

The two most common sources of new/increased noise when things were fine before, is an amp with more gain or a more efficient pair of loudspeakers.