Digital/Opt humming?? Didn't think it did...

Jim Wy

Co/ax vs Digital Optical
I've searched up and down the forums and the above link/debate was the closest I could get to answering my problem that is seriously pi**ing me off :mad:
Met me start with what I have.
AVR 330
JVC DVD player w/ digital opt and digital co/ax out
VCR in (RCA analog)
Sat receiver in

When my DVD player is on (turned on) thru the Monster dig/opt cable (4') to my AVR I get a nasty hum to my l/r speakers in my AVR. Unplug the toslink to either the player or the AVR and "boom" hum gone. Turn off player and hum is gone too. According to the above link---toslinks don't hum!
Is it my DVD player or my receiver? Or the toslink? Should I spend some more money on a dig/co-ax or is there a cheapie way to prove stuff one way or the other? I want to go shopping tomorrow for the right thing and if the guru guys here say it's definitely the toslink I'll just go to FutureShop (have the bill but no box) and yowl a bit.
I've got a hundred movies I want to watch, but the hum is way beyond anything I can stand!

Jim W
PS I just ran a separate 15A ded. plug from my panel to my rec.
Everything else is plugged into either my residential plugs in the house or a UPS.
PPS The dig/opt cable works, just with the hum. I had to change the output of my JVC DVD player to PCM/stream (whatever that is ) to get the DTS output to my receiver.
The DVD player set-up guide also talks about 48k/96/128k sampling rates and other stuff I know nothing about.

BrentMcGhee

Well that is def odd. I can think of a few things for you to try though

*Do you have any analog cables running from the dvd player to the receiver as well as the optical cable. If you do then make sure that the receiver is set to pull in the digital cable and not analog one

*Do you have any other devices hooked up to your receiver using a digital connection (either optical or coax). If so do they humm as well. This could narrow it down to the receiver

*Have you tried using that optical cable to hook up another peice of equipment or another optical cable to hook up the dvd player to the receiver. This could narrow it down to the cable.

*Have you tried using a coax cable to hook up the dvd player to the receiver, if you do not have one lying around to try this you can use any cable that has the male rca ends on it temporarily, they will carry the digital signal as well as the analog signals they are designed for. This could prove it to be the dvd player (more specifically the optical out on the dvd player) or the optical cable.

Hope that helps

TheReaper

If you have any analog cables running from the dvd player to the receiver, try disconnecting them. Sometimes an un-used input will hum, but when you switch to using it (by unplugging the opto), the hum will stop.

By the way, having components plugged into different electrical outlets/circuits. Increases the potential for humm.

disneyjoe7

TheReaper wrote:

By the way, having components plugged into different electrical outlets/circuits. Increases the potential for humm.

Agree try power it all up with 1 outlet, see if the hum goes away.

Jim Wy

Thanks for all the responses :rolleyes:
I had read the first post from Brent last night but didn't have time for a proper answer to his questions so hee goes now...

Do you have any analog cables running from the dvd player to the receiver as well as the optical cable.

No.Out of my player is a 3 set (obviously) of component out into my recv. and the dig/opt. That's it

Do you have any other devices hooked up to your receiver using a digital connection (either optical or coax).

No again. That's the only dig out device I have.

Have you tried using that optical cable to hook up another...

Nope, one cable- one device to out it from :rolleyes:

Have you tried using a coax cable to hook up the dvd player to the receiver

There's the kicker. I wasn't sure if I could use the co-ax in/outs with cheapie rca dollar store jobbies that I have around or if I needed a small piece of co-ax with rca's on temp. Now I know

By the way, having components plugged into different electrical outlets/circuits.

Been there done that. Before I ran the new plug (I'm an electrician w/ dip in elec-mech eng.) I put everything into the UPS/into the residential outlet/into my new plug/into an extension cord run from my split plug in the kitchen.
hummmmmmmm........
9:30 and playing with my wires

Jim

Fallen Kell

Jim, do you have another device that you can plug the optical output from the DVD playing into (something like another reciever or a computer) and listen on headphones or something to see if there is still the buzz/hum? I am just trying to isolate the problem by trying this.

Can you also try removing the component connections from the back of the reciever as well and see if that gets rid of the hum (this will electrically remove the DVD player from interacting with the reciever)?

Also, please try using a different optical cord if you have one laying around (don't go buy an expensive one if you don't have one).

Please let us know what those turn up. I have seen poor implementations of optical outputs and poor implemtations of co-ax digital outputs which are noisy. It may simply be that the DVD player is faulty as well... Optical cords will 99.99% of the time not work at all if there is a flaw in it, so it is usually not the cord if you are still getting a signal.

F1nut

It's your Sat receiver that's causing a ground loop hum.

Jim Wy

Can you also try removing the component connections from the back of the reciever as well and see if that gets rid of the hum (this will electrically remove the DVD player from interacting with the reciever)?

OK I'm pooped and perterterbed but now I know my problem

Apparently my H/K doesn't like my dvd player to have it's component input # the same as it's dig/opt #. By that i mean that if I have my comp-in jacks to my comp#1 input of my receiver I can't have the toslink as input one also.
I'm serious .
As soon as I moved my toslink to input#2 the buzz/hum went down to a level that was almost non-existant. Move my comp cables over to comp input #2 on the back of the receiver (along with toslink #2) and I'm back to the Howard Stern hum again. Keep comp in #2 and move the toslink back to #1 and quiet again. It's either a) dvd player or b) receiver.
Receiver $1300CDN new... dvd player (JVC) $99 on sale. Which one do you think :-)

It's your Sat receiver that's causing a ground loop hum.

Sorry bud, tried that. S-vid unplugged along with the 2 rca jacks in every combination (s-vid out, jacks in- s-vid plugged in, jacks unplugged)

I think I may have it. It's not fixed it's just not quite as broke as it was.

Jim Wy

Fallen Kell

Now that is interesting... Havn't seen/heard that before. My HK DPR-1001 sure doesn't do that, but it is a completely different line then the AVR 330.

Jim Wy

Update:

Gave up with the toslink and went out and bought a 4' digital co/ax. Haven't watched many movies lately so haven't been able to verify one way or the other if things have goten significantly better or not until last night watching De-Lovely (going for the waf factor last night ) Same damned thing as the toslink :mad: .
So I then proceed to go outside to my garage and REMOVE the ground from the ground buss in my panel (dedicated plug with only my AVR plugged in). My dvd player, sat receiver and everything else is either plugged into my residential outlet or a UPS and then into my res. outlet.
So now I have a ded. plug with the gnd removed at the panel and the rest of the stuff plugged into another outlet. Turn on dvd player and still a hum... but not nearly as loud tho.

Funny thing and maybe somebody can tell me their opinions on what this might be... with the dvd player plugged in and "playing" I get a hum on
1. Dolby Dig. in
2. Vid 1, 2, 3, 4.
3. A bit on the radio.

In the OSD of the h/k AVR 330 I have, this is what I get when going under "Input Setup"...
1. A hum on the digital input I'm using but not on any of the others. (ex. if I'm plugged into co/ax 1 on my receiver, co/ax one hums but nothing on opt 1-2-3 or co/ax 2 or 3)
2. A hum on analog. (this will make sense if you have a h/k. The Input Setup
rotates through Opt 1> Opt 2> Opt 3> Co/ax 1> 2> 3> Analog> and then back to the start again)
Turn off player and hum is gone.
Next step tonight is to put my panel cover back on my panel, pull the dedicated plug off the wall, and remove the ground from the circuit.

Any ideas ?!?! Wires packed in the back? Heat? Dvd player? Receiver?

Jim

PS One thing I forgot to say about the player. The hum starts/stops depending on where the actual dvd movie is in the playing. By that I mean when the previews start the hum starts. The two seconds between when the previews stop and the "FBI Interpol Warning" starts is quiet. Between Warning and movie (two sec. again) it's quiet. Movie starts it's going again. It also seems to grow and fade as the movie progresses.

Next step ground loop isolator??

steveinaz

I think F1Nut is right. Buy a Mondial Magic ground loop isolator, either connect it to your cable from the street (to kill hum on all of your cable drops) or connect it at the system. It's the best $99 bucks you'll spend and the Mondial will not degrade your tv picture. 99% of "mysterious" ground hums are attributed to cable tv drops.

My next guess would be a problem with the DVD player. You should not have ANY hum.

Tritonman

Call me crazy but I dont think a ground loop isolator will solve the problem. It may mask it..but ultimately there is still a bigger issue.

Based on your comment..

PS One thing I forgot to say about the player. The hum starts/stops depending on where the actual dvd movie is in the playing. By that I mean when the previews start the hum starts. The two seconds between when the previews stop and the "FBI Interpol Warning" starts is quiet. Between Warning and movie (two sec. again) it's quiet. Movie starts it's going again. It also seems to grow and fade as the movie progresses.

Leads me to believe its either the dvd player..or the receiver. What it sounds like is when the receiver is attempting to decode a digital signal being sent from the dvd player to output audio, thats when the hum begins. also stating that it seems to fade in and out during the movie would lead me to beleive at the times it fades out there is "no" digital signal being sent to the receiver to decode. Either the internal digital decoder in the receiver is having issues or the DVD players digital signal to the receiver is bad.

Easy way to narrow this down is hit walmart..buy the cheapest dvd player you can get with digital outputs..bring it home..hook it up..and listen. If its gone then time to get a new dvd player..if not..well..you know what to do. When testing is complete...return cheap purchased dvd player for refund