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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
jea48
4,398 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?
03-23-14: Tccaux

I by-passed the Furman direct to the SR5008 and buzz remained.
Not sure what you mean. Remember the SR5008 does not use the safety equipment grounding conductor. The power cord that came with the unit is only a 2 wire cord and plug. The SR5008 can pass a ground loop potential, voltage, current from any RCA line input to any RCA output through the outer shell of the RCA jacks. All the signal grounds are common, connected together, in the SR5008.

Interestingly, the coax is also going through the Furman. I disconnected the coax at the wall and the buzz did not go away.
First thought if you disconnected the coax cable from the wall, there by breaking the connection from incoming CATV provider's signal coax cable, that would isolate the Cable TV from the rest HT and 2 channel audio system......
So if we assume the CATV is not causing the ground loop hum what is?

You think it is being caused by the PS Audio DAC . If that is true then you should be able to remove the ground cheater from the C2300 and still not hear the hum.

Edit:
[quote]"I'd previously checked the cable ground to the main grounding and it visually seemed properly connected."
[/quote]
Just curious, when you traced, followed, the ground wire from the CATV grounding block located on the outside of your house where does the other end of the wire connect to?
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
jea48
4,398 posts
 
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.
03-25-14: Tccaux

Well that does make a difference. For one the Jensen ground loop isolator will not work on a satellite system.

"The other end is connected to gang box connected to the house ground."

Gang box??? Connected to the house ground? Do you know where the connection is made?

Quote from link provided below.
Grounding the lead-in antenna cables and the mast help prevent voltage surges caused by static discharge or nearby lightning strikes from reaching the center conductor of the lead-in coaxial cable. Because the satellite dish sits outdoors, wind creates a static charge on the antenna as well as on the cable attached to it. This charge can build up on both the antenna and the cable until it jumps across an air space, often passing through the electronics inside the low-noise block down converter feed horn (LNBF) or receiver. Connecting the coaxial cable and dish to the building grounding electrode system (grounding) helps to dissipate this static charge.

Although nothing can prevent damage from a direct lightning strike, grounding with proper surge protection can help reduce damage to the satellite dish and other equipment from nearby lightning strikes.

The grounding electrode conductor must terminate in accordance with (1), (2), or (3).

(1) Buildings or Structures With an Intersystem Bonding Termination. The grounding conductor for the antenna mast and antenna discharge unit must terminate to the intersystem bonding terminal [Art. 100 and 250.94], as shown in Fig. 1. Bonding all systems to the intersystem bonding termination helps reduce induced potential (voltage) differences between the power and the radio and television systems during lightning events.

(2) In Buildings or Structures Without Intersystem Bonding Termination. The grounding conductor for the antenna mast and antenna discharge unit must terminate to the nearest accessible location on the following:

• Building or structure grounding electrode system [250.50].

• Interior metal water piping system, within 5 ft from its point of entrance [250.52(A)(1)].

• Accessible means external to the building, as covered in 250.94.

• Metallic service raceway.

• Service equipment enclosure.

• Grounding electrode conductor or the grounding electrode conductor metal enclosure.
http://ecmweb.com/qampa/code-quandaries-7

http://ecmweb.com/qampa/code-quandaries-7
.
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!
rbautista
97 posts
 
See if this will work for you. I skimmed so you may have tried something like this. I did the same as you where I disconnected the coax and still had the buzz. The buzz is coming from the cable box.

http://forum.audiogon.com/cgi-bin/fr.pl?bhome&1333386303
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