Ok, I've owned my Denon AVR-3801 (http://usa.denon.com/ArchivedAVReceivers.asp?archivedModelSearch=true&clearCurrent=true&archivedCategory=AV&archivedModel=AVR-3801&imageField.x=14&imageField.y=12)for about 4-5 years without a problem but I recently changed a connection and it has since been producing a low volume, medium pitched hum from all 5 speakers + the sub.

Here is what I have tried to trouble shoot with no luck:

1. Disconnect all components from Monster power strip/surge protector.
2. Add 2 prong adaptor to receiver cable.
3. Disconnect new connections (that seemed to have spawned issue).
4. Disconnect all digital inputs.

Here is what seems to affect the pitch and slightly affects the volume but does not remove the hum:

1. Changing digital-in assignments in the set-up and turning them all off.
2. Changing input from CD to DVD to etc. etc. (even selections that have nothing connected to them and are not assigned to anything).
3. Xbox 360 and HDA2 powered on when reading disc (I had both on at the same time so I'm not sure if it was one or both, I will isolate that tomorrow. I did however disconnect both of them from the 3801 which made no difference).

Here is what removes the hum:

1. Receiver turned off (obvious).
2. Hands touching receiver.
3. Receiver set on carpet.

Right now I have the 3801 connected to a Toshiba HDA2, Xbox 360 (both via optical) and a Pany BDP-10A via 3 sets of Monster RCA's via ext. in for PCM. The 3801 is feeding an Aperion 5.1 rig with a HSU VTF-3 MK3 and I have a cheap A/V cable connected to my XBR3 for OSD. That's about all I can think of for now. I won't have computer access for about the next 18 hrs so apologies in advance for any unanswered questions to help me trouble shoot. I'll get back on asap.

Any aid would be MUCH appreciated, this is going to drive my nuts!

..........................but I recently changed a connection...............
And what change did you make?

And what change did you make?

I got my BD player about 2 weeks ago and connected it via coax but found out I could get PCM out of it if I used 3 sets of RCA's out to my 3801's Ext. in section. I pulled my receiver out far enough to reach the rear and make the connection changes and for the most part it has been humming since.

When I disconnected those connections it continued to hum so I turned it off and tried it the next morning (still w/out the new connections) and the hum was gone. I reconnected it last night with some new cables and the hum is back but again is unresponsive to disconnect or any of the other things I listed in my original post.

Any help from the experts would be most welcome:o

Is this hum coming through your speakers? Or coming from the amp itself?

Here is what removes the hum:

2. Hands touching receiver.
3. Receiver set on carpet.


Those two scenarios sound like you are grounding the thing to me.

Now I asked you about the receiver power-cable in one of your other threads. You said it had only 2 prongs. I think it should have 3. If it doesn't, then you may have the wrong cable (don't know how.)

Is this hum coming through your speakers? Or coming from the amp itself?
He said speakers in one of the other threads.

Those two scenarios sound like you are grounding the thing to me.

Now I asked you about the receiver power-cable in one of your other threads. You said it had only 2 prongs. I think it should have 3. If it doesn't, then you may have the wrong cable (don't know how.)

I was going to see if I could swap it with another cable that had the three today to see if that makes a difference but I'm pretty sure it does have the 3 on the female end that connects to the receiver.

speco2003 - The hum is coming through all 5 speakers and the sub.

If the reveiver only has a two-prong cable going into it, then a three-prong cable in the wall won't help. The receiver uses "insulated shell" instead of "grounded shell" for taking care of safety, which insulates it from house ground.

If it's a differential between the BD player and the receiver, then try using an optical (TOSLINK) cable instead. If that won't work, because you want LPCM (5.1) output, then try using an Ebtech HE8 (http://www.zzounds.com/item--EBTHE8) hum blocker.

I was going to see if I could swap it with another cable that had the three today to see if that makes a difference but I'm pretty sure it does have the 3 on the female end that connects to the receiver.

speco2003 - The hum is coming through all 5 speakers and the sub.
From the looks of things, your power cable may be of the hard wired type vs. the computer cable type. I'm surprised it only has 2 prongs.

One thought I had is to rotate the plug 180 degrees and reinsert it into the wall. I'm probably reaching here, but what they hey.

Here's another straw grasp; try plugging the player into the receiver's power outlet.

If the reveiver only has a two-prong cable going into it, then a three-prong cable in the wall won't help. The receiver uses "insulated shell" instead of "grounded shell" for taking care of safety, which insulates it from house ground.

If it's a differential between the BD player and the receiver, then try using an optical (TOSLINK) cable instead. If that won't work, because you want LPCM (5.1) output, then try using an Ebtech HE8 (http://www.zzounds.com/item--EBTHE8) hum blocker.

Ok, I've confirmed that it does have a 2 prong power cable and it is hard-wired to the receiver. Since I've already tried completely disconnecting the new connections and BD player and it still hums is there anything else I could try before I have to shell out $200 for this hum blocker? (I don't even understand how this thing works, the back of looks like it's desinged for guitar inputs or something.

Ok, I've confirmed that it does have a 2 prong power cable and it is hard-wired to the receiver. Since I've already tried completely disconnecting the new connections and BD player and it still hums is there anything else I could try before I have to shell out $200 for this hum blocker? (I don't even understand how this thing works, the back of looks like it's desinged for guitar inputs or something.
Have you read the "Hum" sticky thread in this forum?

Is everything plugged into the same outlet? If not, try that.

Have you read the "Hum" sticky thread in this forum?

Is everything plugged into the same outlet? If not, try that.

I've read some of that thread but some is a bit over my head. Everything is plugged into a Monster powerstrip/surge protector which is in one outlet. I'll try switching it to another outlet.

I'd rather not plug the BD player into the receiver because then I have to have the receiver on anytime I want to watch a movie, so if I'm watching w/out surround sound it would still be on. I guess it's worth a try but again, even when I unplugged the BD player the hum was still there.

I've read some of that thread but some is a bit over my head. Everything is plugged into a Monster powerstrip/surge protector which is in one outlet. I'll try switching it to another outlet.

I'd rather not plug the BD player into the receiver because then I have to have the receiver on anytime I want to watch a movie, so if I'm watching w/out surround sound it would still be on. I guess it's worth a try but again, even when I unplugged the BD player the hum was still there.
How is your BD player connected to your TV, both audio and video?

The hum blocker is a ground loop breaker. It's basically a 1:1 set of isolation transformers. You can plug a signal in one end, and it comes out the other end, galvanically isolated, meaning no ground loop. You need cables to adapt RCA to tele, but those can be had at any music store for not too much money. Maybe even Radio Shack. It only works on audio frequencies, though; the transformers have too high inductance for a video or digital signal.

However, if the problem is not a ground loop in a specific connection (i e, removing the connection doesn't fix the problem), then the isolator will not fix that problem. The hum blocker will work specifically when there is a hum where there is a connection, but not when the connection is not there; it will allow you to make the connection without creating a ground loop.

The BD player is connected to the TV via HDMI and to the receiver via 3 sets of RCA's.

Based on what I've said so far does anyone think that the humX (http://www.ebtechaudio.com/humxdes.html) from EBtech used inbetween the receiver power and Monster powerstrip; or monster power strip and wall, would make a difference?

Once again, the hum is removed when I place both hands on the sides of the receiver. What does this mean? Does this help narrow down what the issue could be??

The BD player is connected to the TV via HDMI and to the receiver via 3 sets of RCA's.

Based on what I've said so far does anyone think that the humX (http://www.ebtechaudio.com/humxdes.html) from EBtech used inbetween the receiver power and Monster powerstrip; or monster power strip and wall, would make a difference?

Once again, the hum is removed when I place both hands on the sides of the receiver. What does this mean? Does this help narrow down what the issue could be??
You said everything runs into the monster strip. That includes the TV, right?

You said everything runs into the monster strip. That includes the TV, right?

That's correct, but again even when I unplugged it the hum remained.

You need to start with only the receiver, with all speakers connected except the subwoofer and add connections until the hum returns to isolate the ground-loop or ground difference. If your receiver with only the speakers connected is not humming, start by adding the subwoofer. Common culprits are the subwoofer, cable TV connection and any other equipment with three-prong power connections. Your hands on the chassis suggests you have a ground potential difference between two pieces of equipment which could possibly be a defective/broken cable shield. Forget the power strip while doing the troubleshooting.

You need to start with only the receiver, with all speakers connected except the subwoofer and add connections until the hum returns to isolate the ground-loop or ground difference. If your receiver with only the speakers connected is not humming, start by adding the subwoofer. Common culprits are the subwoofer, cable TV connection and any other equipment with three-prong power connections. Your hands on the chassis suggests you have a ground potential difference between two pieces of equipment which could possibly be a defective/broken cable shield. Forget the power strip while doing the troubleshooting.

Thank you for the advice, I'll give that a try tonight. I did try disconnecting the power of each component one by one which did not effect the hum but at no point have I disconnected all of them. I'll try that tonight, thanks again!

Thank you for the advice, I'll give that a try tonight. I did try disconnecting the power of each component one by one which did not effect the hum but at no point have I disconnected all of them. I'll try that tonight, thanks again!
Well you know when the PCM, analog cables are disconnected from the receiver you don't have the hum. It has to start somewhere.

Well you know when the PCM, analog cables are disconnected from the receiver you don't have the hum. It has to start somewhere.

Actually that's not true, when I first connected them to see if it would work that is when the hum came but when I disconnected them the hum was still there. It eventually went away but returned when I reconnected things.

I was able to get the hum to go away by touching and tapping on the side of the receiver but when I turned it on the next day the hum was back. I talked to some guys at Magnolia in BB who thought it sounded like something wrong internally. I'll troubleshoot for a bit more and may just put up with it for a while but I think I'll eventually want to grab a 2808 or something similar to upgrade.

FWIW, my 3300 occasionally starts humming for no apparent reason. Eventually, after cycling the power a/o spinning the main vol up/down on an inactive input, the hum clears.

I suspect this is related to whatever is causing the audio cut-outs/static that my AVR produces as well. I suspect a wonky trace or two (or a connector) on the "motherboard" since the cutouts/static respond favorably to light pressure applied to the main heat sink.

If you can get the hum to start with only the speakers connected and no other equipment you have a situation like HDTVChallenged, a defective receiver. There is no way a speaker (other than a sub) can create a ground loop or difference in ground potential.

Should all the other components be disconnected from power only or totally disconnected from the receiver?

Should all the other components be disconnected from power only or totally disconnected from the receiver?
Both. Try everything.

However it sounds as though things are taking a turn. I had forgotten you said that the hum remained after removing the new RCAs, but did you say it remained after removing everything but the speaker cables?

Are any of your receiver's RCA jacks loose. Sometimes those things can even pop right off, but there could be a loose one grounding to the chassis...

maybe.

Otherwise...

:(

Should all the other components be disconnected from power only or totally disconnected from the receiver?

If there is no hum from the receiver/speaker combo add the connections from another device, plug it in, turn it on, select it and use it. Check for hum and move on to the next component. If the device results in hum, remove it and check the other devices in the same way. Make a note as to which devices produce the hum if it's more than one.