Anybody solve this puzzle? (1 Viewer)

[BobH]

Any Sherlocks out there? I can't figure this one out:

I have a Pany RP56 connected via Toslink to a Classe' preamp/processor. On an increasing basis I am losing the center channel of DD5.1 movies. It is sudden but not complete, there is still sound but about 20dB down. I have narrowed the problem to either the DVD player or the processor but can't figure out which. Here are the conflicting pieces of data:

1. When I put a different (Pany RV30) player in line the problem sometimes goes away and sometimes doesn't.

2. When I turn off and unplug the Pany for an hour, the problem usually goes away. When I do the same to the processor it doesn't.

3. The problem is more common with dirty (rental) discs but not always. Cleaning the discs sometimes helps and sometimes doesn't.

4. Changing Toslink cables doesn't matter. Switching power amp channels puts the problem in another speaker. This is why I have narrowed it to the DVD or processor. Kind of sounds like a capacitor problem or a laser problem but that is pure guessing.

Of course it could be both machines but it would be unlikely to have the same symptom.

Any good solutions or even ideas to try??

 

[Thomas_Berg]

1. When I put a different (Pany RV30) player in line the problem sometimes goes away and sometimes doesn't.

this right here tells me it's probably the processor at fault. call up classe and/or panasonic and explain the problem to them. i'm sure both companies will be more than happy to resolve your woes.

 

[JayDaniel]

Have you tried the digital coax option, instead of Toslink. It's probably not the connector, but if for some reason it was damaged/bad, changing toslink cables wouldn't help. If the coax works, you've fixed it for under $20. Worth a try.

 

[BobH]

Both manufacturers suggest sending the equipment back for service; no suggestions. Since it is intermittent, I expect to get both units back with "found no problem." I would like to narrow it down a little first.

Late news: On the Home Theater SPoT forum for Panasonic, I found owners of Pany 82s and 62s with the same symptoms. Theirs were due to excess vibration (not my case) or the "Enhanced Dialogue" function turned on (not my case). I do find it suspicious that three models have the same symptom, regarless of the possible solutions . . . Could this be a Panasonic design flaw that only shows up intermittently on some players?

Anybody else seen this??

 

[JeremyFr]

never heard of a problem like this I'd lean towards processor though because with digital audio like DD or DTS its data so it either works or doesn't theres now dropping out of 1 channel or a fading in one channel, if this data was missing or corrupted in the stream you'd lose the whole datastream not just the 1 channel. So I'm gonna have to say its your pre/pro.

 

[BobH]

That makes sense, Jeremy. Since the output is still digital through the Toslink, it shouldn't corrupt quite like that. I still find it odd, although possibly coincidental, that the only fix is unplugging the DVD player for a while. That's usually a caps problem.

 

[Parker Clack]

Bob:

I agree with Jay. Try using the coax input instead of the toslink and see if you have the same problem. You might be having trouble with the Toslink connections out of the Pani or the input into the Classe. If you have the same problem then you know it is definitely a DAC problem in one of the units.

Parker

 

[BobH]

Hi Parker, long time;

The Pany RP56 doesn't have a coax output, only optical. Doesn't Jeremy's point make sense though, that the problem of lowered (-20db) audio output in one channel sounds like an analog problem rather than digital? If so, then I can blame the downstream electronics (the Classe). (?)

 

[ManW_TheUncool]

It sounds like you haven't considered the cable between your processor and amp yet unless you swapped the connection at the processor side in #4. Try switching out the cable you use for center channel to the amp before deciding it's the pre/pro.

_Man_

 

[Keith Mickunas]

Switching power amp channels puts the problem in another speaker.

That's the biggest clue there. What exactly do you mean? It sounds like its either the amp or the cable from the pre/pro to the amp. Its most likely not a problem with the player, it just doesn't make sense. If fiddling with your amp connections causes the problem to move to another speaker, why would you think its a player issue? The fact that unplugging the player for a bit causes the problem to go away sometimes is most likely coincidental. Plus the fact that you're using a digital connection also implies the problem is not in the player. Otherwise you'd be seeing completely drop outs or perhaps random noise.

 

[BobH]

Man and Keith;

Ah, yes, the cable ploy! (said with Clouseau accent)

I connected the Center plug from the Pre to another channel on the amp and that channel was bad. I did not think that the cable could be bad, but you're right, it could be. If I switch the cables out completely, that would be instructive. As soon as it acts up again, I will do that, thanks. I was just about to ship out the Pre.

 

[Parker Clack]

Bob:

I still think its the optical cable. I have heard of problems using optical cable as opposed to coax with making a solid connection to the pre/pro.

Also, does your RV30 have a coax output? You could try using the coax off of it it and see if the problem goes away. If it does you know you have a cable issue with the optical output off the 56.

Just a guess on my part but it wouldn't take much to check it out.

Parker

 

[Grant B]

How in the world can you blame this on a Toslink Cable?
There is one bit stream out of the source, not 6. It has to be an analog problem.When I need to get in back of my set up, I need to move the preamp. The right tends to drop out until I push the preamp to amp connector back in.
Digital: it is all or nothing if it's the cable.

I've been wrong before but I am pretty sure on this one

 

[Keith Mickunas]

Bob, so when you moved the cable connecting the center output to a different channel, the speaker that was now connected to that processor's center channel output had dropouts? That definitely means its in the processor or the cable. It could be the processor's RCA connector is bad also, or a more signficant problem in the processor itself. Hopefully its just a flaky cable.

I highly doubt that it could be the digital cable or player. It just doesn't make sense that the problem would be isolated to just one channel. You'd get either complete silence, or perhaps (and I highly doubt this) random noise.

 

[BobH]

Sorry Parker, I think the argument for digital good/bad is a sound one.

Technically the problem could still be the source since the problem has only been located so far to be at the end of the center channel cable. I agree with Keith that it is either something in the prepro (ugh) or in that cable (yea). Naturally I suspect the prepro even though it is a quality product (Classe').

Of course since I substituted the RV30 I have had NOT ONE freaking dropout for days! God hates me.

 

[BobH]

Since a watched pot never boils, I gave up. I am sending the prepro back to Classe' for repair anyway. Five year unconditional warranty (

 

[Keith Mickunas]

Bob is it possible while swapping players you jiggled the cables? Get something playing strictly through the center (shut off the mains if you can) and reach back there and yank on the cable some. If that causes the problem to come back, you know its in the cable or the connector on the pre/pro. Then swap cables and see what happens. Its a quick, easy test that could save you a lot of trouble.

 

[BobH]

Ooh, too late, I already shipped it back. Good idea though.