So in step 2 above the buzz starts when an hdmi cable is plugged in only one end with the other end unplugged? Did you try a differnt hdmi cable in that condition? If the tv hdmi cable is somehow the problem it could affect all your othe tests. You should not have any noise using the RCA cables. At this point I think it is a problem with the tv or a cable but that doesnt jive with the RCA cable noise.

It should not buzz with just the RCA cables hooked up (just speakers, RCAs and two power cords right?).

Go back to this setup and try just one RCA cable at a time. If it stays quiet with only one RCA at a time then start adding them one at a time (i.e. without removing the existing connects) and see where the buzz starts. Maybe your amp has a blown channel or power supply problem?

Regarding the 2 posts above;

XenonMan, you are correct, one end is plugged in at the 7005 and the other end is not plugged in at all. I have tried another brand new Monoprice redmere HDMI cable and the result is the same.

The noise heard with the RCAs was quie loud. Not "oh my god turn it off its too loud" loud, but it was WAY to apparent not to ignore.

EEman; correct, the amp and 7005 were both plugged in, speakers hooked up and the 7005 was connected to the amp via RCAs.

I will unhook the XLRs tomorrow or tonight and try the RCAs one at a time and see if that helps.

Thanks for the contiuing responses guys.

What position was the XLR/RCA selector switch in when the RCA connectors were installed?

Unbalanced.

Something is askew if you are getting noise out of the RCA connection and the XLR has some hum. Maybe your TV has lost its ground somehow or other.

Any thoughts on how to test that? I could try buying a new AC cord. However, keep in mind that running a HDMI cable to another smaller LCD HDTV, on another outlet/circuit, I still get the buzz.

I will do this again with the new unit in case I forgot as part of the troubleshooting procedure.

Before you do that let's go back to the RCA connect. You said with just speakers, amp and pre-pro you get buzzing. I'm assuming the Monster power converter is also hooked up?

What I'm thinking is there might be a ground offset between the pre-pro and the amp. If the offset gets big enough then even balanced connects are not going to help. It also makes sense to me that adding more cables to the pre-pro could make the ground offset worse. Can you ground strap the pre-pro to the amp somehow? Using the cheater plug with the RCA setup would also be interesting as that should float the amp earth ground.

However if you really want to understand what is going on, let's put the volt meter to work. We'll (i.e. you'll) be checking continuity so unplug the Monster from the wall.

1. Unplug everything from the Monster. Put the voltmeter on Ohms and check for continuity between the third prong of the input plug and the third prong of the output plugs. If the pictures I found of the internals of this unit are correct you should read zero ohms.

2. Now check the other two output prongs back to the ground prong of the output (or third prong of the input power if they are tied together). I can't tell from the photo if the neutral wire is tied to the chassis ground of the Monster. This will tell us.

2a. It looks like the outputs of the monster may be isolated from each other. Measure between two output power ports and seee if there is any continuity.

3. Moving to the pre-pro. Unplug everything but the power cord. Check for continuity between each of the two input power pins and the ground on the RCA jacks that goes to the amp (just to be clear that's the shell of the RCA jack NOT the center conductor). Check all RCA jacks to each of the power input pins. All these measurements should result in an open circuit. (Note: This is 14 measurements for a 7-channel system)

4. Now the amp. Do the same measurments as you did for the pre-pro but add the third prong of the power input for a total of 21 measurments. I would expect the RCA shells to be tied (0 Ohms) to the third prong of the power connector (earth ground). I don't know how Outlaw handles the neutral input on their equipment. This test will test us. If you see zero ohms between the third prong and one of the other prongs then the nuetral is tied to earth ground in the chassis.

5. With your newfound understanding of your system you should be able to draw a diagram of where the power and grounds are going for these three units. If not, let me know what you measure. I already have a sketch of what I think is going on but I don't know the internal connects for the units, so no smoking guns yet.

Whew, that was a lot. If you're still reading this, congrats. You might just be an electrical engineer

Thanks EEman, I will try steps 1-5 tomorrow when theres more light in the basement. I did try grounding the Marantz 7005 and the Outlaw 7700 and that did nothing.

I still have a Monster Power Bar at the TV, its a 1200, but the Monster Power 2600 has been replaced by a Tripp Lite Isolation bar and this feeds the amp, pre and some source compenents like the Oppo and the DirecTv DVR.


I got a Hum X and connected the Plasma to it. With the HDMI cable connected at the 7005 to the TV, and multiple HDMI cables connected to the 7005 inputs, except the DVR, no noise!

Connect the DVR via HDMI and the noise returns.

Connect the DVR via component video cables and the buzz is still there.

Tomorrow I am going to swap DVR. The one in th eroom now has a 3 prong plug, but I have a H22-100 (I think) in another room that is only a 2 pronger.

Did more work today;

Already tried to gorund the amp to the preamp before with no luck. Tried a diff DVR (2 prong), no help.

Hooked up a Marantz SR7005 to the amp via RCA and got buzz. The buzz even whirled a bit, changing pitch, loudness, it was wierd.

Hooked up the speakers to the SR7005 along with everything else; BLISS!

Looks like I may be selling the 7700 amp. I hate to, I love it, and it brought great sound to my speakers. But I cant go on with this loop or whatever else is the issue. I will be calling to return the Marantz AV7005 tomorrow



At least I have good sound working in my theatre....