Axiom Home Page Forums General Discussion Technical Questions weird problem with optical sound

This is undoubtably a problem with my AVR, but thought I'd ask here for similar experiences.

I'm driving my new Axiom HT with a Yamaha RXV-1800. So far, I've only set up the M60s, the SWFR, and the center speakers, not the surrounds. Sound is coming from a Mac mini, via the TOSLink connector.

My problem is that the Yamaha shuts down if I have any but the tiniest volume set on the Mac. The Yamaha dealer says that is the way it should be, volume should be controlled from the AVR, and the Yamaha shuts down to protect its circuitry if there's any significant input from the Mac.

This sounds pretty weird to me. It's also a real PITA, cause it's pretty hard to set, say, iTunes on the Mac so that the sound is minimal, yet still audible.

Any thoughts?

Regards,
David

I suppose the Mac's output could be extraordinarily high, but I've never heard of that happening with analog outputs. Is there an Apple Store nearby?

This is truly weird. The optical cable is only carrying the digital image of what to play. Sounds like either a defective AVR or that the MAC's connectors are optical, but they are configured for a different protocol and cause the AVR to misinterpret what it is receiving.

At least with my AppleTV, even though it is connected via optical digital only (TOSLink, just like yours), you can control the volume from it alone (like from the other room, via AppleRemote). In other words, unlike a DVD player, Apple does tinker with the "levels" coming out of the digital connection. That might have something to do with it.

I've never had any problems like you're describing, but my receiver is a Pioneer, so that's obviously going to be a bit different than your Yamaha.

But one thing I'd try first is to replace that optical cable. I've had bizarre problems with optical cables in the past that were always solved with simply getting a new cable. All it takes is one too-aggressive of a tug or a too-sharp of a bend and you start to break fibers. Break enough and weird things can start to happen.

Something to try, anyway.

One other question...

When you set the level on the MacMini to that very small but usable one, how loud is it? Is the sound level comparable to what you'd get from a DVD player, for instance? Or do you have to really crank your Yamaha way up to hear it?

On my AppleTV, the loudest setting is roughly what I expect from a DVD player. In other words, it seems like the AppleTV's volume is just a function of limiting the output.

That seems to be the case on iPods as well--you have to crank them up to get line level output. But that's the analog outs.

Thanks for the help, all. What I didn't mention was that I had the system set up as described, then decided - since doing the surrounds was going to be more work - to stop and listen a while :-) I had no problems, and I'm *sure* I didn't have to fiddle with the volume from the mini. It was only the next day, when I turned the system back on, that the problem appeared, when - theoretically - nothing had changed.

Peter, I do have to crank up the volume on the Yamaha, well past half-way, to get reasonable sound when the mini is set to minimal volume.

Soo, I'm going to:

1) See if there's any problem when I use analogue output from the mini

2) replace the optical cable

and see what happens.

Again, thanks - will post results.

Regards,
David

Hmm. Switched over to analogue input from the mini, and have the same problem (slightly different levels of volume, in fact I have to crank the AVR volume almost to the max to be able to hear it).

I think I'll check all my speaker connections again . . .

And the problem was . . . speaker connections. I disconnected everything, hooked up only the front speakers (making sure everything was tight, tight, tight), and the problem went away.

Sigh. Such a noob.

Thanks again,
David

[Quote] making sure everything was tight, tight, tight [Quote]

Sounds like a reggae song.

making sure everything was tight, tight, tight
got mah speakers cranked up all the night, night, night
tokin' on my joint I'm feelin' right, right, right

The Dundler Mifflin people fight, fight, fight
Get away from me Dwight, Dwight, Dwight
Michael's in his office, feeling bright, bright, bright
But to his comp'ny he's a blight, blight, blight

For some reason, I am now thinking of this Adam Sandler song

Piece of Sh!t Car.

Must be the reggae tones.

Language is NSFW but the video part is SFW.

Funny to hear the backup singers curse like sailors.

I think it's a lot funnier in the radio edit version, where they use horns to bleep it out.

Problem is still there, just intermittent. I *hate* intermittent problems!

I've gone so far as to replace bare wire connections with banana plugs, to no avail. In fact, the frequency of problem occurrence is probably higher.

I have this really bad feeling that I'm going to end up in a serious discussion with the yammie dealer, and we're going to be talking about Mac minis, and how he doesn't know anything about them, and blah, blah, blah. Sigh. The doco on these things is so shit.

Mind you, I'm now the proud possessor of a chinese-made tractor, and that's pretty obscure wrt doco. There are lots of examples, but my favourite is the chapter entitled "Trouble and Shooting" I guess if worst comes to worst, I can shoot the sumbitch (tractor or yammie dealer, I'm easy)

Regards,
David

That's funny.



Sorry, David, wish I could help.

Finally found the problem, and it wasn't the yammie after all, but one of the M60s!! If I replace that M60 with any of the other speakers (including using the same cabling, banana plugs and port on the yammie), all is OK.

Bummer. Have contacted Axiom re how to replace the bad boy.

Regards,
David

Could be a simple check of the interior wiring for each driver, or the speaker terminals. Just losen a few screws and check each driver. That would be easier than shipping a whole speaker back to the states.

Good thought, I'll do that. Given the distance they've travelled, anything might shake loose.

Thanks and regards,
David

With most AVR's, even one little wire strand on a speaker wire touching the opposite terminal can put a receiver into protection mode.

My guess is the same thing might happen within a speaker, just a guess. I'd see what Axiom says as well.

No suggestion from Axiom to fiddle, just return the speaker. They suspect damage in transit: seems likely, as one of the two M60 boxes was fairly messed up, dunno whether this one was in that box.

Sooo, another week or so before perfect sound

Regards,
David