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
theo's avatar
theo
2,690 posts
 
I take it that you are using the unity gain on the C2300 and is that whe the Buzz occurs? Is the buzz present when using the C2300 as 2 channel only? If it is present, is the rest of the system (everything connected to the Marantz) off? You may try lifting the ground on the C2300, I have had a few McIntosh pre-amp processors and had grounding issues with a phono pre-amp buzzing and lifting the ground cleared it right up. Also you may give McIntosh tech support a call and see what they suggest. I have always found them to be very helpful. One last question, is the C2300 the only unit in the group that has tubes? Could it be a failing tube?
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!
jea48
4,451 posts
 
Cable TV?

For a test disconnect the CATV coax cable from the CATV cable box then check for the buzz. Post back your findings.
.
theo's avatar
theo
2,690 posts
 
I would lift the ground at the furman as that would be easiest. But Jea48, raises an interesting point as well. I have at one time or another had ground hum induced by sat TV boxes. And re-reading your comments, have you disconnected the 2300 and determined if the buzz occurs in the remaining channels with just the Marantz on? Also you might try lifting the ground on the Marantz. I don't envy you I have chased these buzzes/hums many times but eventually they do reveal their source of irritation.
More to discover