2. home-theater
  3. 1395084824

Buzz between Marantz SR5008 and Mcintosh C2300

I've got a HT and 2 channel setup I'm trying to marry for use of FL and FR speakers on both.

2 Channel - Computer Channel D/Pure Music to PS Audio Perfect Wave MKII to McIntosh C2300 to Sanders Magtech 2 channel to Snell AIII's.

HT - HD cable/BlueRay/Apple TV/Webcast to SR5008. RR, LR, Cntr and Sub speakers (all Snells) out from the SR5008. FR and FL are Pre-Out (RCA) from SR5008 to C2300 Passthrough designated input. C2300 power triggered from SR5008 to engage Passthrough. FR and FL from C2300 to Sanders.

All are powered through dedicated 20amp line and then through a Furman Elite 20 conditioner.

AND, the problem is a low volume buzz in the sparkers - all channels. I've plugged and unplugged everything, plugged every configuration on the Furman and the only remedy is to take the C2300 out of the chain. No buzz SR5008 to the Sanders. No buzz in the 2 channel set up.

Thoughts? Is the SR5008 pre out to the C2300 just never gonna work? Just to much difference in the equipment configurations? Seems to me this how the C2300 Passthrough should work. Yes?

Or is this just the excuse I need to upgrade the low-end processor? :)

Thanks to all.
Tccaux
tccaux

Showing 6 responses by tccaux

tccaux OP
36 posts
 
Hmmm? The buzz happens when the FL and FR pre out from the Marantz are connected to an input which has been designated as Passthrough on the C2300. In Passthrough mode the Marantz drives unity gain (if I'm understanding you correctly). The buzz is also heard in the other channels which have their speakers being driven directly by the Marantz,

The buzz does not happen when using the C2300 as 2 channel but I must disconnect the Marantz - even if the Marantz is powered off. So wouldn't that eliminate a failing tube?

I might be uncomfortable doing a ground lift but given the Furman configuration, where would you suggest putting the cheater? On the C2300 at the Furman?

Talking to Mac support seems a good idea. Many thanks!
tccaux OP
36 posts
 
Very helpful all. Thanks for the responses. I won't be able to test until this weekend so I'll report back with results.

Theo, I have disconnected the C2300 and the buzz goes away in the other channels.

Jim - Yes, I'm pretty sure all is connected to the Furman, even the cable box.

More info this weekend. Thanks!
tccaux OP
36 posts
 
Well, it was the PS Audio dac that was the main source of the gound loop. I put a cheater on the C2300 and the buzz decreased. I added a cheater to the PS Audio and it went away. I haven't tried removing the cheater off the C2300 since I'm feeling good about NO buzz!

Now, all I have left to figure out is why the power trigger from the SR5008 is constantly on which keeps the C2300 powered on in passthrough mode. I have to unplug the mini plug from the SR5008 to power down the C2300. Been through all the menus, even disengaged all trigger on's on the SR5008. No difference.

Thanks again for the suggestions! Much appreciated.

Tccaux
tccaux OP
36 posts
 
Should have mentioned that. Interestingly, the coax is also going through the Furman. I disconnected the coax at the wall and the buzz did not go away. I by-passed the Furman direct to the SR5008 and buzz remained. I'd previously checked the cable ground to the main grounding and it visually seemed properly connected. Am I missing other possible confirmation to eliminate coax as source?

Many thanks
tccaux OP
36 posts
 
I removed the cheater from the C2300 but left on the PS DAC and the buzz came back. I put the cheater back on the C2300 and, upon really close listening, it's apparent that the buzz doesn't entirely go away. It just gets barely audible.

Traveling again this week so will wait until I'm home and have time to pull things out and try the cheater on other units in the chain. For the moment, it's just nice to be listen to HT without a noticeable buzz.

Its a satellite cable btw. The ground is connected to the satellite chassis mounted on the roof. The other end is connected to gang box connected to the house ground.

Thanks
tccaux OP
36 posts
 
All interesting but am I correct to assume that since the buzz did not go away with the cable/satellite coax disconnected at the wall that it's been eliminated as a source of the buzz? And that the process of elimination will be using cheaters on each piece of gear connected to the Furman?

Thanks for the continued feedback!
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