I would try it on the TV just as an experiment. If you try it on the 7700 don't use it at too high of power. Also the ground pins on the XLR connectors may not function fully for noise reduction but should be OK.

Okay, went out and got three of the "3 prong to 2 prong" adapters. I disconnected everything except the XLR cables from the preamp to the amp and all speakers;

* Just the amp on, dead quiet!

* Took the 3 prong Plasma electrical cord and used a 2 prong adapter and plugged it in and I got buzz

* Used a 3 prong adapter on the Outlaw 7700 amp with the TV using the 3 prong cord and I got buzz

* Used a 3 prong adapter on the amp AND on the plasma and the buzz is 90% GONE!


I tried connecting the TV to both the dedicated outlet and also to the Monster Power bar and that did not make a difference.

For experimental value, I connected a ethernet cable and downloaded and installed the updated frimware. While the process was running, there was no buzz, but when it restarted, the buzz was there.

Thoughts?

Have you tried connecting a ground wire between the Marantz the 7700 and the TV? It sounds like a ground loop between the amp and the TV. Connecting a ground between the chassis of all 3 eliminates that loop.

Remove the 3 prong to 2 prong adapters and do that? I probably could as a temporary fix to see if it kills the buzz. Doing so as a long term solution would be very difficult as they are not near each other. The amp, pre, DVR, Oppo, and the CD and DVD jukeboxes are in a wooden stereo cabinet about 15 feet away and on a perpindicular wall to the TV, PS3, Wii and HD DVD player.

Just temporary for testing. I would leave it as is with the adapters and fine a good chassis screw and connect a piece of speaker wire to all three.

So right now you only have power cords, HDMI and XLR (and speaker wires) in the system correct?

Have you tried unbalanced connects from the Marantz to the Amp? (Takes the XLR out of the equation)

Have you tried running component to the TV from the Marantz, taking the HDMI out of the equation?

If either of these works then the grounding scheme related to the cable removed is wrong/broken.

I have some other suggestions that may provide insight however they may cause damage to your speakers, so we'll leave that on the table for now. Basically I want to get the Marantz out of the loop and feed audio directly from the TV to the amp but the TV specs don't show analog outputs so I don't know how to do this gracefully. Any ideas?

Do you have a volt meter?

Not necessarily.
It is entirely possible that the "feed" to the TV has lost its ground. I have seen cases where landscapers busted the grounding wire to antenna / satellite / cable ...

I have used these for problems with cable -- http://www.jensen-transformers.com/iso_vid.html

You might also check to see if there is a grounding block and ground rod with nice un-corroded wire firmly attaching them -- http://www.amazon.com/Cables-Go-41037-Si...grounding+cable


If you have a grounding issue with DirectTV this might have enough bandwidth to work -- http://www.mcmelectronics.com/product/33...CFY1DMgodxi8AxQ


Good Luck!

The pre, amp and the TV?

Yes, I have a voltmeter.....

I get the new Marantz tomorrow; regarding plugging stuff in and making connections, do I need to have everything off and unplugged when making the connections (XLR, RCAs, HDMIs, etc...)?

It is always safest to have all equipment turned off especially the amp and subwoofers. Once it is all off you just have to disconnect the old and reconnect the new.

I received the new AV7005 last week. I hooked it up yesterday and slowly started to connect stuff. At first I tried using RCA cables to connect the 7005 to my Outlaw 7700 amp. That did not go well, awful noise. I took them out and connected my Outlaw XLR cables and with just those 2 components hooked up and my speakers connected, DEAD SILENCE!

Then I started connecting stuff, Here are the results of my testing scenarios;

#1; Preamp connected to Amp via XLR (7 channels), Amp feeding speakers, amp on = no buzz, turn on preamp = no buzz. All else unplugged and unconnected (no power or HDMI cables, no subwoofer)
#2; Connect a HDMI cable to HDMI out #1 at 7005, EXTREMELY low buzz, I will rate it at .5 or 1/2.
#3; Connect above HDMI to HDMI in #1 at unplugged Plasma HDT, buzz a little more noticeable, I will rate it at “1”.
#4; Plug in plasma, buzz is heard, same as when plasma is not plugged in. I will rate it the same, a “1”.
#5; Attach cheater plug to TV and plug in, stays about a “1” and a crackle is heard every 5-8 seconds. Remove cheater plug.
#5; Attach both DirecTv RG6 lines to DVR, buzz stays a “1”. Plug in DVR, buzz remains a “1”.
#6; Disconnect the HDMI out from the 7005 and buzz goes back to a “.5”.
#7; Connect a HDMI in at number 3 on the back on the 7005, buzz is a tad louder, a “1”. Connect the HDMI at the DVR and the buzz is a tad louder, now at “1.5”.
#8; Disconnect the HDMI cable at both ends for the DVR (at the DVR and the input at the 7005) and disconnect the HDMI out on the 7005 and buzz is back at “.5”.
At this point the TV is still off but plugged in.
#9; Connect a HDMI to an output on the 7005 and to HDMI 1 on the plasma and the buzz is back at 1.
#10; Connect the HDMI from the PS3 (plugged in but not on) with no HDMI connected to the 7005 out, buzz is at “.5”. Connect the HDMI out at the 7005 and connected at the plasma and the buzz is back to a “1”.
#11; Connect the HDMI from my Oppo BDP-93 (not plugged in) and buzz is at “1”. Plugged in, it remains a “1”.

Somewhere somehow there seems to be a ground loop occurring, and to me it seems like when I connect the HDMI to the TV to complete a connection between the 7005 and the TV, the ground loop is either started or exaggerated to the point where it is audible. The buzz rating of .5 is barely heard from 3 feet. Very tolerable if I was on my counch watching/listening to something. With the buzz rating of “1”, it can be heard at a distance of 12-13 feet, however it is very, very, low. When standing within 1 foot of the speaker it is quite noticeable.

I also tried conecting the Plasma to the same Tripp Lite Isobar using a tick 3 prong extension cord, and also plugged it in to a different outlet on a different circuit. Neither helped.

I connected the other sources(PS3, DVD Jukebox, and the DirecTv DVR via HDMI and the buzz got up to about a “2”. This is easily heard, but not "loud" at 12 feet.

I think I am going to try an AV Receiver and try that and see if it works, with and without the amp.